Article

Influence of light on health‐promoting phytochemicals of broccoli sprouts

Authors:
  • Spanish National Research Council- (CEBAS-CSIC)
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Abstract

BACKGROUND: Broccoli (Brassicaceae) is a rich source of phytochemicals (glucosinolates and phenolic compounds) and micronutrients (vitamins and minerals). Germinated broccoli sprouts contain much higher levels (10–100 times) of aliphatic (glucoraphanin) and indolic glucosinolates than the inflorescences. This quality characteristic of broccoli sprouts plays an important role in human health and disease prevention. Although it is known that genetic and environmental factors can affect the composition of broccoli inflorescences, the influence of such factors on the seeds and sprouts has not been widely reported. Therefore the aim of this study was to determine the effect of light versus dark growth conditions on the phytochemical composition (vitamin C, phenolic compounds and glucosinolates) of broccoli sprouts. RESULTS: Broccoli sprouts grown in the light were found to have much higher concentrations of vitamin C (by 83%), glucosinolates (by 33%) and phenolic compounds (by 61%) than those grown in the dark. During a 7 day period there was a clear and analogous trend in both treatments, with a general reduction in concentrations over time. Among the different organs studied (seeds, cotyledons, stems and roots), the cotyledons contained the highest levels of bioactive compounds, while the roots contained the lowest. CONCLUSION: Light treatment of sprouting broccoli seeds increased their concentration of health-promoting phytochemicals, mainly during the first 3–5 days of development. Therefore the younger broccoli sprouts are a better source of bioactive compounds for the consumer than the inflorescences. Copyright

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... Most of these studies have been conducted on higher plants, whereas only a few information is available on sprouts, which are usually cultivated in the dark or under limiting light conditions. In 2008, Perez-Balibrea and co-workers [30] reported an increase in the phenolic content of broccoli sprouts grown under 400 μmolm −2 s −1 fluorescent light, compared to those grown in the dark. An increment in vitamin C has been found in white-light growing Chinese kale sprouts, while a monochromatic blue light was responsible for a higher level of phenolic compounds and antioxidant capacity in the same species [31]. ...
... Even though sprouts are commonly grown etiolated, in our experiment the exposure to specific light quality significantly improved morphological development and phytochemical content. This is in agreement with previous studies where a clear benefit of light over dark was found, especially concerning sprouts phytochemical composition [30]. In our study, Dark-exposed sprouts only elongated the hypocotyl, as well as incremented the number of stomata on both adaxial and abaxial surfaces at 0 and 0.3 Gy compared to other light regimes (Table S3). ...
... Indeed, the effects of LEDs on plant growth and physiology are known to be species and cultivar-specific; within the same species/cultivar, the responses may vary also depending on the light intensity, plant developmental stage and the interaction with other environmental parameters [44,45]. Major attention has been directed towards the use of red wavelength alone and/or in combination with blue light, since these wavelengths are known to be the most useful for the photosynthetic process [30]. The most commonly reported effects of red wavelengths on plants are the promotion of stem elongation and accumulation of dry biomass [44]; while the blue light seems to reduce plant total height, leaf area and to induce more compact and thicker phenotype [23,45]. ...
Article
Sprouts are nutritious food, easy to produce even in extra-terrestrial platforms, where the exposure to ionising radiation can alter their morpho-anatomical traits and phytochemical content. The aim of this study was to evaluate whether sprout production under specific light wavelengths can mitigate the negative effects of radiation and/or stimulate the induction of hormesis. Germinated seeds, with actively proliferating cells, of mung bean were irradiated with increasing X-ray doses (0–20 Gy) and then incubated in controlled conditions under four different light regimes: dark (D), white light (W), red light (R), red-blue light (RB). Morpho-anatomical development of the sprouts was investigated through light-microscopy and their content of flavonoids and isoflavones was quantified by HPLC. Two significant conclusions emerged: 1) RB wavelength induces hormesis by stimulating the production of antioxidant compounds; 2) R wavelength offsets the harmful effects of radiation on morpho-anatomical traits, even at the highest X-ray dose.
... En los primeros días de germinación las semillas de brócoli (Brassisca oleracea L.) alcanzan valores nutritivos de 10 a 100 veces más que las plantas en estado adulto (Fahey et al., 1997). Específicamente este germinado contiene compuestos fenólicos del tipo flavonoide, ácidos hidroxicinámicos, vitamina A, C, E, K, ácido fólico (B9), riboflavina (B2), hierro, calcio y potasio, indol-3-carbinol y sulforafano (Pérez-Balibrea et al., 2008;Moreno et al., 2010;Bjorkman et al., 2011;Manchali et al., 2012). ...
... No. de 254 nm 254 nm (2019) compuestos fenólicos (Kim et al., 2005;Pérez-Balibrea et al., 2008). Así mismo, Long y Jenkins (1998) observaron que la luz azul induce a las enzimas involucradas en el metabolismo fenólico, como la fenilalanina amoníaco-liasa y la chalcona sintasa. ...
... La extracción de dichos compuestos la realizaron con agua destilada a diferencia de nuestro estudio que la extracción de los compuestos se realizó con metanol, obteniendo 1.8 mg EQ de muestra seca a los 6 días de germinación, por lo que las diferencias entre ambos estudios pueden deberse por el tipo de extracción utilizada. En un estudio diferentes,Pérez-Balibrea et al. (2008) obtuvieron 310.2 mg por 100 g de muestra fresca de compuestos fenólicos en extractos metanólicos de germinados de brócoli cultivados por 16 h luz blanca/8 h oscuridad durante 7 días. Aunque los flavonoides son los polifenoles mayormente distribuidos en las plantas(Martínez-Valverde et al., 2000) no necesariamente quiere decir que un alto contenido de fenoles indica un alto contenido de flavonoides(Bedascarrasbure et al., 2004). ...
Article
Light is one of the most important environmental factors that regulate the development of plants. The main objective of this study was to determine the influence of different light conditions on the antioxidant activity and the phenolic compounds content in broccoli sprouts. The broccoli sprouts were produced in a rotary spreader with 10 s of water spraying every 90 min, 1 h of ventilation every 3 h, 2 rpm, 99 % RH and 3 photoperiod conditions: each one consisted of 11 h of white light, in addition to 5 h of red light, 5 h of blue light or 5 h of green light, emitted by Leds, depending on the treatment, and 8 h of darkness. The red light condition generated 0.71 g GS/g seed with a significant difference (p < 0.05). The blue light obtained significant difference (p < 0.05) in the inhibition of both ABTS and DPPH radicals with an EC50 of 1.1232 mg/mL and 1.1577 mg/mL respectively. The highest phenols content was obtained with the red light condition of 10.17 mg EA/g and the flavonoid content 1.86 mg EQ/g. The different light conditions favor the increase of bioactive compounds in broccoli sprouts in the rotating germination device.
... En los primeros días de germinación las semillas de brócoli (Brassisca oleracea L.) alcanzan valores nutritivos de 10 a 100 veces más que las plantas en estado adulto (Fahey et al., 1997). Específicamente este germinado contiene compuestos fenólicos del tipo flavonoide, ácidos hidroxicinámicos, vitamina A, C, E, K, ácido fólico (B9), riboflavina (B2), hierro, calcio y potasio, indol-3-carbinol y sulforafano (Pérez-Balibrea et al., 2008;Moreno et al., 2010;Bjorkman et al., 2011;Manchali et al., 2012). ...
... No. de 254 nm 254 nm (2019) compuestos fenólicos (Kim et al., 2005;Pérez-Balibrea et al., 2008). Así mismo, Long y Jenkins (1998) observaron que la luz azul induce a las enzimas involucradas en el metabolismo fenólico, como la fenilalanina amoníaco-liasa y la chalcona sintasa. ...
... La extracción de dichos compuestos la realizaron con agua destilada a diferencia de nuestro estudio que la extracción de los compuestos se realizó con metanol, obteniendo 1.8 mg EQ de muestra seca a los 6 días de germinación, por lo que las diferencias entre ambos estudios pueden deberse por el tipo de extracción utilizada. En un estudio diferentes,Pérez-Balibrea et al. (2008) obtuvieron 310.2 mg por 100 g de muestra fresca de compuestos fenólicos en extractos metanólicos de germinados de brócoli cultivados por 16 h luz blanca/8 h oscuridad durante 7 días. Aunque los flavonoides son los polifenoles mayormente distribuidos en las plantas(Martínez-Valverde et al., 2000) no necesariamente quiere decir que un alto contenido de fenoles indica un alto contenido de flavonoides(Bedascarrasbure et al., 2004). ...
Article
Full-text available
Light is one of the most important environmental factors that regulate the development of plants. The main objective of this study was to determine the influence of different light conditions on the antioxidant activity and the phenolic compounds content in broccoli sprouts. The broccoli sprouts were produced in a rotary spreader with 10 s of water spraying every 90 min, 1 h of ventilation every 3 h, 2 rpm, 99 % RH and 3 photoperiod conditions: each one consisted of 11 h of white light, in addition to 5 h of red light, 5 h of blue light or 5 h of green light, emitted by Leds, depending on the treatment, and 8 h of darkness. The red light condition generated 0.71 g GS/g seed with a significant difference (p < 0.05). The blue light obtained significant difference (p < 0.05) in the inhibition of both ABTS and DPPH radicals with an EC50 of 1.1232 mg/mL and 1.1577 mg/mL respectively. The highest phenols content was obtained with the red light condition of 10.17 mg EA/g and the flavonoid content 1.86 mg EQ/g. The different light conditions favor the increase of bioactive compounds in broccoli sprouts in the rotating germination device.
... The variation in the moisture content for different soaking time might be due to the breakdown of cell wall of legumes thereby absorbing water rapidly. Titratable acidity was highest in flour prepared from 18 h soaked horsegram (1.20%) and was lowest in 0 h i.e. control (0.67%) owing to the enhanced ascorbic acid content during soaking in legumes, that might be due to reactivation of enzyme (L-Galactono-c-lactone dehydrogenase) involved in the oxidation of L-galactono-1, 4-lactone to ascorbic acid (Pérez-Balibrea et al. 2008). ...
... Thus, increase in the activity of this enzyme with germination confirmed its involvement in the biosynthesis of ascorbic acid during germination (Smirnoff 2000). Similar findings have been reported in soybean by Pérez-Balibrea et al. (2008). With increase in the germination time, the level of the protease activity get increased (Pal et al. 2016) and is thus responsible for the decrease in total protein content of the germinated mass. ...
... Higher amount of ascorbic acid was found in flour prepared from seed geminated in the presence of light (10 mg/100 g) and possible reason behind it may be the synthesis of secondary metabolites and photo protection. Thus, depicting that light during germination has significant effect on ascorbic acid (Pérez-Balibrea et al. 2008). Total protein content of the flour was influenced significantly by germination conditions, which might be due to reduced or eliminated antinutrients that affect protein utilization (Mubarak 2005). ...
... mg GAE 100 g -1 DW and 337.7± 51.90 mg GAE 100 g -1 , respectively. Broccoli is a rich source of phytochemicals (glycols and phenol compounds) as well as trace elements vitamins and minerals (Perez-Balibrea, et al., 2008). The analysed broccoli seed also had a high TPC content (208.00±19.30 ...
... However, the results of scientific literature have shown that a higher TPC was achieved by germinating seeds in the presence of light. (Perez-Balibrea, Moreno, & Garcia-Viguera, 2008). ...
... However, the results of scientific literature have shown that a higher TPC was achieved by germinating seeds in the presence of light. (Perez-Balibrea, Moreno, & Garcia-Viguera, 2008). in TPC during germination process, hemp seeds scavenging activity decreased. ...
Article
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Consumers are increasingly consuming sprouted seeds due to their low calories content, nutritional value, as well as beneficial effects on human health. Sprouts contain many bioactive compounds such as minerals, fibre, vitamin C, carotenoids and phenolic compounds. The aim of this study was to determine the effects of darkness, light and time total phenolic content and scavenging activity in alfalfa (Medicago sativa), radish (Raphanus sativus), broccoli (Brassica oleracea) and hemp (Cannabis sativa) seeds during germination. The seeds were washed, soaked in water by ratio of 2:1 (water : seeds) for 12±1 h and then germinated in light and dark conditions at a temperature of 22±2 °C and a relative humidity of 85±2% for different times (12, 24, 36 and 48 hours) in a climatic chamber ICH110 (Memmert, Germany). The quality changes of germinated seeds are determined by phenol content and scavenging activity. Un-germinated seeds were used as a control. The results of current studies show that after germination the highest increase in total phenols was in radish, broccoli and alfalfa seeds. The scavenging activity (SA) was higher after 48 hours of germination in all seed types compared to un-germinated seeds both in darkness and in light. This study shows that sprouted edible seeds are an excellent source of total phenolic compounds and has a high scavenging activity.
... cymosa Duch.) due to their characteristic taste qualities remain highly popular with consumers. 21 Like all the sprouts, broccoli sprouts constitute a good source of easily available nutrients, vitamins and minerals, 18,19,55 but their further benefits, such as antioxidant, anti-inflammatory or anticancer activity, may result from the occurrence of specific specialized metabolites. Two of the most important groups of phytochemicals in broccoli sprouts are glucosinolates and polyphenols. ...
... Two of the most important groups of phytochemicals in broccoli sprouts are glucosinolates and polyphenols. 13,17,20,55,56 Glucosinolates are S-linked glucosides, characteristic of the Brassicaceae family, that upon the disruption of plant tissues are hydrolyzed by myrosinase into volatile isothiocyanates responsible for the biological effects of the parent compounds and for the odor and taste of the sprouts. 57,58 The polyphenols of broccoli sprouts are represented mostly by sinapic acid derivatives (SADs), including mainly mono-, di-and trisinapoyl esters of glucose or gentiobiose. ...
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Broccoli sprouts represent health-promoting food, rich in antioxidant and anti-inflammatory phytochemicals, among which sulfur compounds are most extensively investigated. In this study, the phenolics of broccoli sprouts (Brassica oleracea var. italica ‘Cezar’) were examined for variability during germination and influence on the sprouts bioactivity. In the sprouts germinated in darkness, 31 compounds were identified by UHPLC-PDA-ESI-MS3 (18 sinapic acid derivatives, 8 glucosinolates, 5 flavonoids) with sinapoyl components (SADs) prevailing among polyphenols. The total SADs decreased during germination (down to 4.85 mg/g dw in 6-day-sprouts), but the concurrent changes in molecular structures of the leading compounds (sinapine was replaced by sinapate sugar esters and sinapic acid) increased the antioxidant activity of the sprouts. The glucosinolate-depleted 6-day-sprout extract (34.2 mg SADs/g dw) effectively protected human plasma components against peroxynitrite-induced oxidative damage in vitro (reduced the levels of 3-nitrotyrosine, lipid hydroperoxides and thiobarbituric acid-reactive substances) and enhanced the non-enzymatic antioxidant status of plasma. It also downregulated the release of pro-inflammatory cytokines (TNF-α, IL-6) from LPS-stimulated human peripheral blood mononuclear cells and increased the production of IL-10, an anti-inflammatory mediator. The relevant activity parameters of sinapic acid indicated that SADs might be linked to the observed effects. The results support the application of broccoli sprouts in oxidative stress- and inflammation-related diseases and the role of SADs as their bioactive components next to glucosinolates.
... Citric acid improves the antioxidant content of foods since it stimulates a larger synthesis of nutraceutical compounds that function as antioxidants, among that are the phenolic compounds and flavonoids among them [2]. They have a synergistic impact on growth, yield and a few chemical constituents of the many crops yet as dominant the incidence of most fungi on many crops [3]. ...
... An increasing the measured growth characters (plant height etc.) was thanks to that these fertilizers leading to a lot of accessibility micronutrients (Fe, Mn and Zn) and antioxidant like citric acid to be absorbed by the recorded plants. The positive result of the antioxidants included citric acid on growth could be attributed to their positive action on enhancing cell divisions and protective plant cells from free radicals that's accountable for plant senescence, , additionally to be attributed to their result on counteracting drought, salinity and diseases stresses as well as they have an auxinic action, consequently enhancing plant growth characters and stimulates a greater synthesis of nutraceutical compounds that function as antioxidants, among which are the phenolic compounds and flavonoids among them [2,26,27]. Citric acid can degrade conjugated phenols such as tannins to other simpler phenolic compounds by hydrolyzing and promotes the synthesis of compounds derived from phenylpropanoids and activates signaling cascade that increase antioxidant activity [3,28]. These compounds can accumulate in cellular vacuoles [29]. ...
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The objective of this investigation was to study the helpful effects of foliar application with antioxidant citric acid in combos with some micronutrients on growth, yield and a few chemical constituents of maize ( Zea mays L.) plants. The plants were grown up in clay soil, and foliar sprayed with eleven treatments (0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0.5%) of combined fertilizer (citrine) which contains (15% citric acid, 2% Fe, 2% Mn and 2% Zn). The obtained results indicated generally that each one studied vegetative growth parameters (i.e. plant height, stem diameter, number of leaves /plant, dry weight of leaves) similarly as grain yield /fed. and some of their components (i.e. ear length, ear diameter, number of rows/ear, number of grains/row, grain weight/ear, weight of 100 grain and ear weight/plant) and some chemical constituents of leaves (chlorophyll a, b, total caroteniods, anthocyanin, total carbohydrates, total and reducing sugars, total free amino acids, total indoles, nitrogen, phosphorous and potassium) and grain protein %, were accrued with application of the various treatments. The maximum values were obtained from the treatment of 0.3%. On the contrary citrine treatments minimized reducing sugars and free phenol in leaves as compared to the control. The simplest results were obtained by the application of citrine treatment at 0.3%. Hence, it can recommend using citrine fertilizers as foliar application at the speed of 0.3% for improving growth, yield and chemical constituents of maize plants.
... Petri plates were transferred to germinator with controlled conditions. Broccoli sprouts were produced under four different environmental treatments: Elicitor treatment (Instant yeast Saccaromyces cerevisiae (0.1%) was dissolved in distilled water and autoclaved, Germinating seeds were watered with distilled water (6ml/24h), After second, third and fourth day of germination, sprouts were watered with elicitor) 12 ,Temperature treatment (Temperature achieved by placed petriplates in germinator with controlled temperatures at 10ᴼC, 20ᴼC and 30ᴼC) 13 , Dark treatment ( Darkness were achieved by completely wrapping the sprouting plates with domestic aluminum foil) 14 ,UV light treatment (Seven days old sprouted plates were placed in laminar air flow with UV light for 2 hrs.) 15 . ...
... Our study is comparable to previous studies that proved yeast extract were an effective elicitor for improving phenolic compounds of broccoli sprouts 12 . Phenolic compounds were considered as main antioxidants and health-beneficent secondary plant metabolites in brassica spesies 14 . It should be noted that in w w w . ...
Article
Broccoli sprouts contains health promoting phenolic compounds, proteins, vitamin C and flavonoid that can be influence by applying UV light, elicitor (yeast), light and dark light treatment, different temperatures (10 0 C, 20 0 C and 30 0 C). In this study 0.1% yeast elicitor significantly increases the content of gallic acid, proteins and quercetin, whereas significantly decreases the content of ascorbic acid. Much Higher concentration of gallic acid, ascorbic acid, proteins, and quercetin were founds, when broccoli sprouts were grown in light conditions. Phytochemical content in broccoli sprouts increased when they grown at 30 0 C, but decreased when they grown at 10 0 C, 20 0 C. Sprouts were exposed to UV light for 120 minutes decreases the phytochemical content. Content of phytochemicals in germinated broccoli plays important role in the health of human.
... tomentosa). A number of bioactive compounds can be influenced by several parameters such as climatic conditions, soil, stage of maturity and genotype [44,45]. In our case, the trees from which the samples were obtained grow between residential blocks of an urban settlement (approximately 2 hectares), are the same maturity stage (40-year-old trees) and the soil and climatic conditions are similar. ...
... Flavonoid fraction is probably responsible for the antiradical properties of lime extracts. The content of biologically active compounds depends on their accumulation during the growing season [44,45]. Polyphenols are the main plant bioactive compounds, which act as natural antioxidants [46]. ...
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The significant healing effect of Tilia platyphyllos Scop. and Tilia cordata Mill. flowers are well known. However, the flowers of Tilia tomentosa Moench. are not suitable for harvest due to their toxic effects. To investigate the diverse background of this effect, we applied a functional miRNA-based marker, mannose expression analysis and determined the content of bioactive compounds. Out of nine tested markers, three (miR160, miR167 and miR408) provided reproducible miRNA-based loci and two of them (miR160 and miR398) enabled the acquisition of fingerprinting specific to flower and leaf samples of T. platyphyllos and T. tomentosa. The most pronounced profiling was specific for miR408 marker, the function of which is connected to plant defense and adaptation mechanisms. We confirmed the suitability of microRNA-based markers for polymorphism determination of flowers of selected species of lime-tree. The highest values of antioxidant activity, flavonoids, total polyphenols and phenolic acids content have been reached in silver linden flowers. When comparing the transcription activity of mannose in flowers, more than 30 times higher levels of mannose transcripts for the silver linden flowers was observed.
... Many studies have tested the effect of light intensity and quality on sprout phytochemical content, with contrasting results depending on the PPFD (photosynthetic photon flux density) and on the specific wavelengths [18,32,33]. However, the general tendency is to have a higher quantity of antioxidants in light-grown sprouts compared to dark-grown ones [34][35][36][37], even if sprouts grown in the light can be smaller compared to those grown in the dark [38]. ...
... Although sprouts are commonly produced in the absence of light, it has been demonstrated that even a low amount of PPFD may induce positive outcomes during germination. For example, Pérez-Balibrea et al. [34] found in light-grown broccoli sprouts an increment in phenolic compounds (by 61%) compared to sprouts grown in the dark. In contrast, Qian et al. [54] found in Chinese kale sprouts grown under blue-light, the highest levels of total phenolics and anthocyanins, as well as the strongest antioxidant capacity. ...
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In the last decades, there has been a growing interest in the production of sprouts, since they are a highly nutritious food, particularly suitable for indoor farming in urban areas. Achieving sprout production in indoor systems requires an understanding of possible alterations induced by the microclimate. The aim of this study was to analyze the combined effect of presence/absence of light and high/low air relative humidity (RH) on mung bean sprouts. Morpho-anatomical development and functional anatomical traits in hypocotyl were quantified. The content of antioxidants, soluble sugars, and starch were measured for nutritional and functional purposes. Different RH regimes mainly induced morpho-anatomical modifications, while the presence/absence of light changed the content of antioxidant compounds. Increments in stele diameter at high RH suggest a higher water uptake and conductivity, compared to the low RH treatment; low RH and light induced anatomical traits improving plant water transport (reduced number of cortical layers) and increased the production of antioxidants. The overall results suggested that RH and light, already at the early stages of development, affect the plant's nutritional value. Therefore, the combination of light and low RH allows the production of antioxidant-rich mung bean sprouts to be used as a food supplement.
... Among these compounds, the most abundant GLSs are glucoraphanin, glucoiberin, glucoerucin, glucobrassicin, and neoglucobrassicin [41]. In particular, glucoraphanin accounted for over 50% of the total GLSs content, which was quantified in the range of 605 to 1172 mg per 100 g of fresh weight (FW) [42][43][44]. ...
... Their phenolic profile composed mostly of sinapic acid, gallic acid, flavonoids (quercetin and kaempferol), and other hydroxycinnamic acids (chlorogenic, caffeic acid, and ferulic acids) ( Table 3). In general, total phenolic and flavonoid contents were determined to be in the ranges of 74-453 mg per 100 g of FW and 95-105 mg per 100 g of FW, respectively [43,65,77]. ...
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Sprouts and microgreens, the edible seedlings of vegetables and herbs, have received increasing attention in recent years and are considered as functional foods or superfoods owing to their valuable health-promoting properties. In particular, the seedlings of broccoli (Brassica oleracea L. var. Italica) have been highly prized for their substantial amount of bioactive constituents, including glucosinolates, phenolic compounds, vitamins, and essential minerals. These secondary metabolites are positively associated with potential health benefits. Numerous in vitro and in vivo studies demonstrated that broccoli seedlings possess various biological properties, including antioxidant, anticancer, anticancer, antimicrobial, anti-inflammatory, anti-obesity and antidiabetic activities. The present review summarizes the updated knowledge about bioactive compounds and bioactivities of these broccoli products and discusses the relevant mechanisms of action. This review will serve as a potential reference for food selections of consumers and applications in functional food and nutraceutical industries.
... Light is not only an energy source for plant photosynthesis, but also a regulator of plant physiological activity. Numerous studies have shown that light quality, light intensity, and photoperiod have extensive regulatory effects on plant morphogenesis, physiological metabolism, growth and development and nutritional quality (Anderson, 1999;Ward et al., 2005;Qian and Kubota, 2009;Pérez-Balibrea et al., 2010). ...
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Light is an important environmental factor which affects plant growth, through changes of intensity and quality. In this study, monochromatic white (control), red (660 nm), and blue (430 nm) light-emitting diodes (LEDs) were used to treat tea short cuttings. The results showed the most adventitious roots in blue light treated tea cuttings, but the lowest roots in that treated by red light. In order to explore the molecular mechanism of light quality affecting adventitious root formation, we performed full-length transcriptome and metabolome analyses of mature leaves under three light qualities, and then conducted weighted gene co-expression network analysis (WGCNA). Phytohormone analysis showed that Indole-3-carboxylic acid (ICA), Abscisic acid (ABA), ABA-glucosyl ester (ABA-GE), trans-Zeatin (tZ), and Jasmonic acid (JA) contents in mature leaves under blue light were significantly higher than those under white and red light. A crosstalk regulatory network comprising 23 co-expression modules was successfully constructed. Among them, the “MEblue” module which had a highly positive correlation with ICA (R = 0.92, P = 4e-04). KEGG analysis showed that related genes were significantly enriched in the “Plant hormone signal transduction (ko04075)” pathway. YUC (a flavin-containing monooxygenase), AUX1, AUX/IAA, and ARF were identified as hub genes, and gene expression analysis showed that the expression levels of these hub genes under blue light were higher than those under white and red light. In addition, we also identified 6 auxin transport-related genes, including PIN1, PIN3, PIN4, PILS5, PILS6, and PILS7. Except PILS5, all of these genes showed the highest expression level under blue light. In conclusion, this study elucidated the molecular mechanism of light quality regulating adventitious root formation of tea short cutting through WGCNA analysis, which provided an innovation for “rapid seedling” of tea plants.
... Another successful example was Chavan (Chavan et al., 2011) who enhanced the accumulation of -tocopherol and pigment productions in cell cultures of Carthamus tinctorius utilizing abiotic elicitors, NaCl and MgSO 4 . Light conditions have been mentioned to provide a significant influence on phytochemicals of broccoli sprouts (Perez-Balibrea et al., 2008). Furthermore, in a variety of plant species, the synthesis of flavonoid compounds was induced by UV radiation as an adaptive response, because aromatic secondary metabolites engage in protect plant DNA from the damaging effects of UV radiations (Li et al., 1993;Dixon and Paiva, 1995). ...
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Verbasceae plants are known for the high diversity of their secondary metabolites. Most of them were used as traditional and healthful effects, therefore the aim of this project focused on enhancing the accumulation of some phytochemical compounds in callus tissue of common mullein (Verbascum thapsus L.) that cultivated under abiotic elicitors (internal and external stimuli), their included; sugar nutrition (six types of sugars as a carbon source were added separately to the medium with two concentrations 30 and 60 g/l), likewise exposure to different light conditions. Changes in three phytochemicals concentrations (coumarin, eugenol and thymol) were determined using HPLC analysis. Compared to the control (plant mother), the callus tissues showed a motivating increase in coumarin and eugenol content, while decreasing in thymol concentrations. Likewise, the incubation at blue and red light condition, also the exposure to the ultraviolet radiation (UV-C) highly enhanced production of coumarin and eugenol compounds. While the most in vitro treatments inhibited the production of thymol compared to mother plants. The data indicate that sugars and light stresses may be trigger the assembly and accumulation of some phytochemical compounds in cultures of common mullein (in vitro).
... Light induces expression of GL biosynthesis genes, resulting also in diurnal rhythms, while transcriptional profiling revealed genotype-specific gene responses to temperature but only a limited correlation between GL-related gene expression and GL levels (89). The data on field-grown broccoli pointed out that total GL content and individual profile are rather modulated by the interaction temperature × photoperiod (14,90,91,117). During broccoli sprouts growth, Guo et al. (92) detected the highest 4-methylsulfinylbutyl-GL and 4-methylsulfinylbutyl isothiocyanate at 25 • C, but lower (20 • C) or higher (30 • C) temperatures decreased their levels in cultivar Youxiu. ...
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Owing to several presumed health-promoting biological activities, increased attention is being given to natural plant chemicals, especially those frequently entering the human diet. Glucosinolates (GLs) are the main bioactive compounds found in broccoli (Brassica oleracea L. var. italica Plenck). Their regular dietary assumption has been correlated with reduced risk of various types of neoplasms (lung, colon, pancreatic, breast, bladder, and prostate cancers), some degenerative diseases, such as Alzheimer's, and decreased incidence of cardiovascular pathologies. GL's synthesis pathway and regulation mechanism have been elucidated mainly in Arabidopsis. However, nearly 56 putative genes have been identified as involved in the B. oleracea GL pathway. It is widely recognized that there are several pre-harvest (genotype, growing environment, cultural practices, ripening stage, etc.) and post-harvest (harvesting, post-harvest treatments, packaging, storage, etc.) factors that affect GL synthesis, profiles, and levels in broccoli. Understanding how these factors act and interact in driving GL accumulation in the edible parts is essential for developing new broccoli cultivars with improved health-promoting bioactivity. In this regard, any systematic and comprehensive review outlining the effects of pre-and post-harvest factors on the accumulation of GLs in broccoli is not yet available. Thus, the goal of this paper is to fill this gap by giving a synoptic overview of the most relevant and recent literature. The existence of substantial cultivar-to-cultivar variation in GL content in response to pre-harvest factors and post-harvest manipulations has been highlighted and discussed. The paper also stresses the need for adapting particular pre-and post-harvest procedures for each particular genotype in order to maintain nutritious, fresh-like quality throughout the broccoli value chain.
... Another successful example was Chavan (Chavan et al., 2011) who enhanced the accumulation of -tocopherol and pigment productions in cell cultures of Carthamus tinctorius utilizing abiotic elicitors, NaCl and MgSO 4 . Light conditions have been mentioned to provide a significant influence on phytochemicals of broccoli sprouts (Perez-Balibrea et al., 2008). Furthermore, in a variety of plant species, the synthesis of flavonoid compounds was induced by UV radiation as an adaptive response, because aromatic secondary metabolites engage in protect plant DNA from the damaging effects of UV radiations (Li et al., 1993;Dixon and Paiva, 1995). ...
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Verbasceae plants are known for the high diversity of their secondary metabolites. Most of them were used as traditional and healthful effects, therefore the aim of this project focused on enhancing the accumulation of some phytochemical compounds in callus tissue of common mullein (Verbascum thapsus L.) that cultivated under abiotic elicitors (internal and external stimuli), their included; sugar nutrition (six types of sugars as a carbon source were added separately to the medium with two concentrations 30 and 60 g/l), likewise exposure to different light conditions. Changes in three phytochemicals concentrations (coumarin, eugenol and thymol) were determined using HPLC analysis. Compared to the control (plant mother), the callus tissues showed a motivating increase in coumarin and eugenol content, while decreasing in thymol concentrations. Likewise, the incubation at blue and red light condition, also the exposure to the ultraviolet radiation (UV-C) highly enhanced production of coumarin and eugenol compounds. While the most in vitro treatments inhibited the production of thymol compared to mother plants. The data indicate that sugars and light stresses may be trigger the assembly and accumulation of some phytochemical compounds in cultures of common mullein (in vitro).
... Researchers have demonstrated that various preharvest treatments, such as choosing a certain genotype, providing certain light conditions or environmental temperature (Perez, Moreno, & García, 2008), as well as altering irrigation and fertilisation regimes (Tiwari, Brunton, & Brennan, 2013) can prevent fruit losses associated with poor practices. The application of such methods results in the accumulation of soluble sugars, ascorbic acid, and carotenoids, particularly in greenhouse-cultivated vegetables (Bian, Yang, & Liu, 2015). ...
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The prevention of certain chronic diseases has been related to tomato (Solanum lycopersicum L.) consumption. The demand for high-quality tomatoes has, therefore, increased rapidly. As a climacteric fruit, tomato will only ripen to full colour postharvest. Trusses of mature-green greenhouse tomatoes of a red (‘Cherry Little Wonder’) and a yellow cultivar (‘Goldilocks’) were illuminated, preharvest, with either red (RL) (peak at 634 nm, 120 ± 20 µmol m–2 s–1) or blue (BL) LED lights (peak at 450 nm, 120 ± 20 µmol m–2 s–1) for 8 h per day for seven consecutive days. These on-plant RL and BL treatments significantly affected fruit colour and pigment concentration. Both light treatments enhanced the accumulation of lycopene, thereby significantly enhancing the nutritive value of the fruit. Similarly to lycopene, the β-carotene concentrations also increased following RL and BL exposure, again more so in the red than the yellow cultivar. Both light treatments also enhanced the speed of colour change by 5 days for the red and by 10 days for the yellow cultivar, resulting in either the desired red or the yellow colour. Our findings could be employed to improve quality and shorten the ripening period of tomato, while mechanisms involved in the biosynthesis and accumulation of these carotenoids require further investigation.
... On the other hand, there are certain phytonutrients that increase with the passage pf storage time in rocket leaves such as glucosinolates, isothiocyanates, and amino acids (Bell et al., 2017). The kinetics of AA degradation is effected by temperature, pH, enzymes, oxygen, metallic catalysers and light (Santos and Silva, 2008;Pérez-Balibrea et al., 2008). The effect of storage time and temperature on vitamin C degradation of rocket leaves has been reported by (Kim and Ishii, 2007;Spadafora et al., 2016;Mastrandrea et al., 2017). ...
Article
A comprehensive study of the feasibility of hyperspectral imaging in visible (400–1000 nm) and near infrared (900–1700 nm) regions was investigated for prediction and concentration mapping of Vitamin C, ascorbic acid (AA), dehydroascorbic acid (DHAA) and phenols in wild rocket (Diplotaxis tenuifolia) over a storage span of 12 days at 5 °C. Partial least squares regression (PLSR) with different data pretreatments and wavelength selection resulted in satisfactory predictions for all parameters in the NIR range except DHAA. Prediction models were used for concentration mapping to follow changes over time. The prediction maps will be comprehensively study to assess the pixel to pixel variation within the rocket leaves. The PLSR models for Vitamin C, AA and phenols yielded an R² of 0.76, 0.73 and 0.78, respectively in external prediction with root mean square errors approximately equivalent to those of reference analysis. Conclusively, hyperspectral imaging, with the correct mapping approach, can be a useful tool for the prediction and mapping of phytonutrients in wild rocket (Diplotaxis tenuifolia) over time.
... Changes in the biochemical content of germinated legumes can be induced by stresses. On plants, phytochemicals are induced in response to biotic and abiotic stresses, acting as natural phytoalexins to protect plants against these stresses (Pérez-Balibrea et al., 2008). Abiotic stresses, such as drought, salinity, extreme temperatures, chemical toxicity and oxidative stress are serious threats to plant growth (Khayatnezhad et al., 2010). ...
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The aim of this study was to evaluate the impact of abiotic stress conditions on the synthesis of compounds with antioxidant properties in germinating seeds. The seeds of edible lentils (Lens culinaris L.), alfalfa (Medicago sativa L.), and mung beans (Vigna radiata L.) were germinated for 120 hours. We studied the influence of abiotic stress on the amount of dry matter, vitamin C and phenolic compounds, as well as flavonoids, in germinated seeds. The use of higher than optimal germination temperatures led to a higher accumulation of dry matter in the mung bean, while the accumulation of phenolic compounds and flavonoids was higher in the alfalfa sprouted seeds. Oxidative stress substantially increased the content of dry matter in the seeds of mung bean, and more vitamin C was found in the lentils. The conditions of abiotic stress in lentil seeds during their sprouting reduced the amount of phenolic compounds in comparison to that in the control variant of the seeds. However, these same conditions (with the exception of oxidative stress) benefitted the accumulation of phenolic compounds in alfalfa seeds.
... Our results showed that agro-ecological conditions can influence antioxidant activity. Several parameters, such as weather, soil, varieties, stages of maturity and climatic conditions during the year, influence the amount of bioactive compounds in medicinal herbs [23,24]. Kobus et al. [25] studied antiradical activity of water, ethanolic and aqueous acetonic extracts from Ginkgo green and yellow leaves. ...
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The aim of this study was to characterize extracts from the leaves of Ginkgo biloba L. from selected Slovakian localities in terms of the content of bioactive constituents, antioxidants and their antimicrobial properties. The results indicated that the content of antioxidants was sample-specific, and this specificity was statistically significant. Ginkgo biloba L. from the locality of Košice had the best activity determined by the free radical scavenging activity (DPPH) (1.545 mg Trolox equivalent antioxidant capacity (TEAC)/g fresh matter (FM)) as well as the molybdenum-reducing antioxidant power (35.485 mg TEAC/g FM) methods. The highest content of total polyphenols (2.803 mg gallic acid equivalent (GAE)/g FM) and flavonoids (4.649 μg quercetin equivalent (QE)/g FM) was also detected in this sample. All samples of G. biloba leaf extracts showed significant antimicrobial activity against one or more of the examined bacterial species, and Staphylococcus aureus subsp. aureus CCM 2461 was found to be the most susceptible (minimal inhibition concentration MIC50 and MIC90 values of 64.2 and 72.2 μg/mL, respectively). Based on the results it was concluded that Ginkgo biloba L. extracts can be used as antimicrobial and antioxidant additives. Selected miRNA-based molecular markers were used to examine the environmental adaptability of Ginkgo biloba L. An almost-complete genotype clustering pattern based on locality was determined in the analysis Int. J. Mol. Sci. 2020, 21, 3087 2 of 20 that involved a species-specific gb-miR5261 marker. Morphologically specific exemplar, cv. Ohatsuki, was excluded.
... By contrast, R light regulates photomorphogenesis, energy distribution, and the photosynthetic apparatus [10,11]. Studies show that the phytochemical accumulation in vegetables is affected by genotype and environmental factors, including light [12]. Subsequent studies have shown that the ratio of B and R light is crucial for the accumulation of pigments and phenolic compounds in plants grown in a closed environment [13,14]. ...
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Plant production in urban areas is receiving much attention due to its potential role in feeding the rapidly growing population of city dwellers. However, higher energy demands in urban plant factories are among the key challenges that need to be addressed. Artificial lighting is responsible for the most significant levels of energy consumption in plant factories; therefore, lighting systems must be modulated in consideration of the sustainable food–energy nexus. In this context, low light irradiation using blue (B) and red (R) LED was applied in a plant factory for the growth of red leaf lettuce (Lactuca sativa L. var Lollo rosso) to evaluate the growth performance and functional quality. The tested B (450 nm) and R (660 nm) light ratios were B/R = 5:1; 3:1; 1:1; 1:3, and 1:5, with a photosynthetic photon flux density (PPFD) of 90 ± 3 µmol m−2 s−1. In the plant factory, the photoperiod, temperature, RH, and CO2 conditions were 16 h d−1, 20 ± 0.5 °C, 65% ± 5%, and 360 ± 10 μL L−1, respectively. The lettuce was harvested 10 and 20 days after the commencement of LED light treatment (DAT). In this study, normal photosynthetic activity and good visual quality of the lettuce were observed. The results show that a higher fraction of R (B/R = 1:5) significantly increased plant growth parameters such as plant height, leaf area, specific leaf area, plant fresh and dry weight, and carbohydrate content. By contrast, a higher fraction of B (B/R = 5:1) significantly increased the photosynthetic parameters and contents of pigment and phenolic compounds. The rate of photosynthetic performance, carbohydrates (except starch), and content of phenolic compounds were highest after 10 DAT, whereas the pigment contents did not significantly differ at the different growth stages. It is concluded that high R fractions favor plant growth and carbohydrate content, while high B fractions favor photosynthetic performance and the accumulation of pigments and phenolic compounds in red leaf lettuce under limited lighting conditions. This study will help in designing artificial lighting conditions for plant factory production to reduce energy demands.
... The use of fungicides to combat these diseases is restricted because they tend to appear close to harvesting, making the search for alternatives to the use of phytosanitary products of priority concern. As well as its economic value, broccoli is considered a foodstuff of high nutritional value due to its content in mineral and phytochemicals, mainly glucosinolates, with their beneficial properties for health (Pérez-Balibrea et al., 2008;Francisco et al., 2017), which has no doubt contributed to the increase in its demand during recent years. In this work, we study the effect of ozone, applied in the form of ozonated water during crop development (pre-harvest) on the production and quality of broccoli, particularly the effect on the content of bioactive components (glucosinolates, phenolic compounds and vitamin C). ...
Article
The impact of pre-harvest applications of ozonated water via the shoot (T1), roots (T2) and combined (T3) on the visual and nutritional quality of broccoli was evaluated. None of the treatments produced visual damage or affected the physical quality of broccoli. Application to the shoot decreased the incidence of Alternaria from 18% to 2–3%. In addition, this treatment reduced the content of glucoraphanin and increased that of glucobrassicin, without modifying the total concentration of glucosinolates or vitamin C and phenolic compounds. Application to the roots increased the content of all the glucosinolates and main phenolic compounds. Lastly, the combined application to both plant parts had the same benefits for head quality as the root-only treatment, improving on the effects of the leaf-only treatment. The results underline the potential of using ozonated water to improve the commercial and nutritional quality of broccoli.
... Similarly, broccoli (B. oleracea) sprouts grown in the light synthesized 33% more GLs in comparison to sprouts grown in the darkness (Pérez-Balibrea et al., 2008), which further demonstrates that light stimulates GLs biosynthesis in Brassica species. Coincidentally, during seedling development of Chinese cabbage (B. ...
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We evaluated the effects of phosphate (Pi-deficiency: 0.1 mM; Pi-sufficiency: 0.5 mM), phosphite (low-Phi: 0.1 mM; medium-Phi: 0.5 mM; and high-Phi: 2.5 mM), and two mean daily photosynthetically active radiations (lower PAR: 22.2 mol ⋅ m-2 ⋅ d-1; higher PAR: 29.7 mol ⋅ m-2 ⋅ d-1), as well as their interactions, on flavonoid, nitrate and glucosinolate (GL) concentrations and growth characteristics in hydroponically grown Brassica campestris cv. Mibuna Early and Brassica juncea cv. Red Giant. As expected, higher PAR increased dry matter and contrariwise decreased number of leaves but only in B. campestris. Total flavonoid and individual flavonoid compounds increased with the higher PAR value in B. campestris. Pi-sufficiency resulted in a lower quercetin concentration in both species, the isorhamnetin and total flavonoid concentrations in B. campestris, and the cyanidin concentration in B. juncea, in comparison to Pi-deficiency. Similarly, Pi-sufficient plants exhibited lower GL concentration, especially alkyl-GLs in B. campestris and alkenyl-GLs and an aryl-GL in B. juncea. Pi did not affect the nitrate concentration in either species, and nor did Phi influence the flavonoid concentrations in either species. In B. campestris, medium Phi (0.5 mM) increased the 1-methoxyindol-3-ylmethyl GL concentration by 28.3%, as compared to that observed at low Phi. In B. juncea, high Phi level increased the but-3-enyl-GL concentration by 18.9%, in comparison to values recorded at medium Phi. B. campestris plants exposed to higher PAR increased total flavonoids concentration. In both Brassica species, higher PAR stimulated the alkyl-, alkenyl-, and indole-GLs. The interaction of lower PAR and increasing Phi significantly decreased flavonoid concentration in B. juncea, whereas increasing Phi at higher PAR increased such concentration in this species. The same combination reduced the concentration of 2-phenylethyl- and indol-3-ylmethyl-GL in B. juncea. The highest indol-3-ylmethyl-GL concentration was observed when Pi was deficient combined with medium Phi in B. juncea. Thus, PAR, Pi and Phi may modulate flavonoid, GL and nitrate concentrations in Brassica species, which may be a useful tool to improve the nutraceutical quality of these leafy vegetables if properly managed.
... Recent studies have shown that the GLs, a precursor substance for I3C biosynthesis, in cruciferous plants are regulated by light. For example, broccoli sprouts growing under light rather than dark have higher levels of vitamin C, GLs, and phenols (Santiago et al., 2008). Besides, blue light can also regulate plant growth and development and promote the biosynthesis of plant secondary metabolites (Huché-Thélier et al., 2016). ...
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Indole-3-carbinol (I3C), an important secondary metabolite with strong anti-cancer ability, is widely found in cruciferous plants. Light and phytohormones are one of the most important external and internal signals, respectively, that control the growth, development, and secondary metabolism of the plant life cycle. However, there are few studies about the influence of the blue light and salicylic acid (SA) on the regulation of I3C accumulation. In this study, a negative correlation was found between the content of I3C and SA in different species. Among this, broccoli and Arabidopsis thaliana were chosen for further studies. We observed that blue light treatment increased the accumulation of I3C, and exogenous SA treatment significantly inhibited the accumulation of I3C in broccoli sprouts. Based on the RNA sequence, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that blue light promoted the enrichment of differentially expressed genes (DEGs) in plant hormone signal transduction pathways. More specifically, downregulated expression of genes related to SA biosynthesis and upregulated expression of I3C genes related to metabolic pathway were observed under blue light. Taken together, these results suggested that SA negatively regulates blue light-induced I3C accumulation in broccoli sprouts.
... Phenolic acids were determined as described previously by Pérez-Balibrea et al. (2008) with some modifications. Briefly, 40 mg freeze-dried tissue was homogenized in 3 ml of 80 mL/100 mL methanol and incubated at 45 • C for 2 h with gentle shaking. ...
Article
Lepidium latifolium L. from Ladakh Himalayas is a high source of 2-propenyl glucosinolate (GLS). To utilize it as a functional food, differently aged sprouts (1st-, 2nd-, 3rd-, 4th-, and 8th-week) were evaluated for phytochemical, nutritional, and antioxidant properties. A combination of 2-propenyl and benzyl GLS was found in significantly (p ≤ 0.05) higher quantity during the first four stages. Benzyl GLS decreased during the 8th-week stage, with a concomitant increase in 2-propenyl GLS. The content of GLSs was found under the transcriptional regulation of the MYB transcription factors. Despite the similar metabolic content of GLSs, higher myrosinase activity during the 3rd-week might increase their bioavailability. Lepidium sprouts also contain higher amounts of nutritionally important vitamin C, carotenoids, phenolic acids, and fatty acids than observed in other Brassica species. The antioxidant potential in sprouts corroborated with the content of phenols and flavonoids and was higher during the first three weeks. Our results suggest that sprouts during the 3rd-week stage showed a unique combination of GLSs and qualitative and quantitative phytochemical superiority, hence could be promoted as a functional food.
... In addition, the higher intensity of the glucosinalbin content reduction as the germination advanced may be explained by its use as antioxidant/nutrient reserves during plant development, in special during cotyledon development that was higher under light conditions (Table 1). Similarly, Pérez-Balibrea et al. (2008) observed higher consumption of antioxidants (mainly, vitamin C) in cotyledons of broccoli sprouts during germination under a light/darkness regime compared with germination under complete darkness (24-h darkness regime). ...
Article
White mustard seeds is a rich source of the glucosinolate glucosinalbin, although these levels are reduced during seed germination. This study aimed to enrich glucosinolate contents of white mustard sprouts during 9 days of germination (22±2ºC) using different elicitors. The effect of such elicitors on the carotenoid biostynthesis during germination was also studied. As chemical elicitors, methyljasmonate (MeJA-10-100 μM) and salicylic acid (SA-50-300 μM) were applied daily as a spray during germination (light/darkness photoperiod (16/8-h) or 24-h darkness). As an abiotic physical elicitor, UV-B radiation (52 kJ m⁻²) was applied on 8-days-old sprouts (photoperiod or darkness) followed by 24-h acclimatization. The cotyledon area/stem length was not affected by elicitor treatments. The highest glucosinalbin retention was achieved with MeJA-25 or SA-300 after 9 days under the photoperiod, and even enhanced up to 280% with UV-B. The highest carotenoid contents were achieved in MeJA-50 or SA-50 samples after 9 days under photoperiod. UV-B applied to MeJA-50 and SA-50 samples enhanced β-carotene/lutein contents by 560/280 and 620/350%, respectively, under the photoperiod. Glucosinolate and carotenoid enhancements with elicitors were lower during germination under darkness. Conclusively, germination with MeJA or SA enriched glucosinolate and carotenoid contents of white mustard and even increased after UV-B treatment.
... In several studies, both under non-stress and various stress conditions, the role of CA in promoting antioxidant enzyme activities has been reported [16,58,[101][102][103]. CA functions as an elicitor of phenylpropanoid-derived compounds and activates signaling cascades to increase antioxidant activity [104]. Other interpretations of CA's role in abiotic stress tolerance have been proposed as well. ...
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Several recent studies have shown that citric acid/citrate (CA) can confer abiotic stress tolerance to plants. Exogenous CA application leads to improved growth and yield in crop plants under various abiotic stress conditions. Improved physiological outcomes are associated with higher photosynthetic rates, reduced reactive oxygen species, and better osmoregulation. Application of CA also induces antioxidant defense systems, promotes increased chlorophyll content, and affects secondary metabolism to limit plant growth restrictions under stress. In particular, CA has a major impact on relieving heavy metal stress by promoting precipitation, chelation, and seques-tration of metal ions. This review summarizes the mechanisms that mediate CA-regulated changes in plants, primarily CA's involvement in the control of physiological and molecular processes in plants under abiotic stress conditions. We also review genetic engineering strategies for CA-mediated abiotic stress tolerance. Finally, we propose a model to explain how CA's position in complex metabolic networks involving the biosynthesis of phytohormones, amino acids, signaling molecules , and other secondary metabolites could explain some of its abiotic stress-ameliorating properties. This review summarizes our current understanding of CA-mediated abiotic stress tolerance and highlights areas where additional research is needed.
... Light is one of the major factors for growth. It represents the main signal perceived by plants, and it has been largely demonstrated that different light qualities, light intensity, and photoperiod have broad regulatory effects on the morphogenesis, physiological metabolism, growth and development, and nutritional quality of plants [1][2][3][4]. Plant morphogenesis and its related aspects are mainly regulated by various photoreceptors which are activated by photons in the blue, red, and far-red regions of the light spectrum [5]. Lightemitting diodes (LEDs) are an emerging source of light in protected and indoor cultivations. ...
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To improve microgreen yield and nutritional quality, suitable light spectra can be used. Two species—amaranth (Amaranthus tricolor L.) and turnip greens (Brassica rapa L. subsp. oleifera (DC.) Metzg)—were studied. The experiment was performed in a controlled LED environment growth chamber (day/night temperatures of 24 ± 2 °C, 16 h photoperiod, and 50/60% relative humidity). Three emission wavelengths of a light-emitting diode (LED) were adopted for microgreen lighting: (1) white LED (W); (2) blue LED (B), and (3) red LED (R); the photosynthetic photon flux densities were 200 ± 5 µmol for all light spectra. The response to light spectra was often species-specific, and the interaction effects were significant. Morphobiometric parameters were influenced by species, light, and their interaction; at harvest, in both species, the fresh weight was significantly greater under B. In amaranth, Chl a was maximized in B, whereas it did not change with light in turnip greens. Sugar content varied with the species but not with the light spectra. Nitrate content of shoots greatly varied with the species; in amaranth, more nitrates were measured in R, while no difference in turnip greens was registered for the light spectrum effect. Polyphenols were maximized under B in both species, while R depressed the polyphenol content in amaranth.
... Previous results showed that GSLs follow the circadian rhythms by varying continuously in a day (Rosa and Rodrigues, 1998), which were decreased in Brassica oleracea at day time, but their accumulation started to increase at night (Rosa et al., 1994). In addition, the amount of GSLs showed different fluctuations with light quality and intensity (Pérez et al., 2008). In this study, total GSLs contents had obviously accumulated in siliques under shading (Figures 2, 4A-J), in accordance with previous results FIGURE 4 | The GSLs profiles with significant differences in rapeseed siliques. ...
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Glucosinolates (GSLs) are naturally occurring secondary metabolites found in the Brassicaceae family, which mainly synthesize in the siliques with a wide range of functions. In this study, we investigated the effects of lights on metabolites in siliques of rapeseed through ultra high-performance liquid chromatography (UPLC)-heated electrospray ionization (HESI)-tandem mass spectrometry (MS/MS). A total of 249 metabolites, including 29 phenolic acids, 38 flavonoids, 22 GSLs, 93 uncalculated and 67 unknown compounds, were identified in siliques of rapeseed. Meanwhile, 62 metabolites showed significant differences after shading treatment, which were mainly GSLs and unknown compounds. Interestingly, the amounts of 10 GSLs had high accumulation levels in siliques, while the expression levels of their corresponding biosynthetic genes (AOP, GSL-OH, IGMT, and ST5a) were obviously reduced after shading treatment. Further evidence showed that the amounts of GSLs were significantly reduced in seeds, in accordance with the expression profiles of transporter genes (BnaGTRs). Our findings indicated that lights could affect the accumulation and transportation of GSLs from siliques to seeds in rapeseed. Therefore, this study facilitates a better understanding of metabolic characteristics of siliques and provides insight into the importance of light for GSLs accumulation and transportation in siliques and seeds of rapeseed.
... It is quite clear that light is needed to achieve higher GR contents in broccoli sprouts. Pérez-Balibrea et al. [4] reported 33% higher concentrations of total GL relative to broccoli sprouts grown in the dark. ...
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Broccoli sprouts contain 10–100 times higher levels of sulforaphane than mature plants, something that has been well known since 1997. Sulforaphane has a whole range of unique biological properties, and it is especially an inducer of phase 2 detoxication enzymes. Therefore, its use has been intensively studied in the field of health and nutrition. The formation of sulforaphane is controlled by the epithiospecifier protein, a myrosinase co-factor, which is temperature-specific. This paper studies the influence of temperature, heating time, the addition of myrosinase in the form of Raphanus sativus sprouts in constant ratio to broccoli sprouts, and other technological steps on the final sulforaphane content in broccoli sprout homogenates. These technological steps are very important for preserving sulforaphane in broccoli sprouts, but there are some limitations concerning the amount of sulforaphane. We focused, therefore, on the extraction process, using suitable β-cyclodextrin, hexane and ethanol, with the goal of increasing the amount of sulforaphane in the final extract, thus stabilizing it and reducing the required amount sulforaphane needed, e.g., as a dietary supplement.
... For instance, raw herbal materials cultivated and collected from the same area of vegetation may have different phytochemical profiles and may thereby exhibit different bioactivities. Pérez-Balibrea et al. (2008) showed that the light treatment of sprouting broccoli (Brassicaceae) seeds increases the concentration of health-promoting phytochemicals, such as vitamin C, glucosinolates, and phenolic compounds. Odjegba and Alokolaro (2013) simulated the effects of a drought and varying salinity conditions in Acalypha wilkesiana plants, which resulted in a decrease in the quantity of alkaloids, flavonoids, and tannins in the extracts, as well as an increase in the saponin production levels. ...
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Environment fluctuations can influence a plant's phytochemical profile via phenotypic plasticity. This adaptive response ensures a plant's survival under fluctuating growth conditions. However, the resulting plant extract composition becomes unpredictable, which is a problem for highly standardized medicinal applications. Here we demonstrate, for the first time, the feasibility of tracking the changes in the phytochemical profile based on real-time measurements of a few environment and extract-preparation variables. As a result, we predicted the chromatograms of Blumea balsamifera extracts through an imputation-augmented convolutional neural network, which uses the image-transformed temporal measurements of the variables. We developed a sensor network that collected data in a greenhouse and a training algorithm that concurrently generated a data representation of the implicit plant-environment interactions leading to the mutable chromatograms of leaf extracts. We anticipate the generic applicability of the method for any plant and recognize its potential for addressing the standardization problems in plant therapeutics.
... Cotyledons were revealed in our study as the site of enhanced glucosinolate accumulation in response to H 2 O 2 treatment. In the same way, Pérez-Balibrea et al. [63] described the broccoli cotyledons as the organ with the highest bioactive compounds accumulation (vitamin C, glucosinolates and phenolics). The cotyledons showed no bleaching in response to H 2 O 2 application on their surface, in contrast to real leaves of the rocket plant subjected to the same treatment. ...
Article
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Broccoli sprouts are known as a rich source of health-beneficial phytonutrients: glucosinolates and phenolic compounds. The production of phytonutrients can be stimulated by elicitors that activate the plant stress response. The aim of this study was enhancing the nutritional value of broccoli sprouts using hydrogen peroxide (H2O2) as an elicitor. Daily spraying with H2O2 (500–1000 mM) enhanced the accumulation of glucosinolates, doubling their content in the cotyledons of 16/8 h photoperiod-grown 7-day sprouts compared to the water-treated controls. The application of H2O2 on dark-grown sprouts showed a smaller extent of glucosinolate stimulation than with light exposure. The treatment affected sprout morphology without reducing their yield. The H2O2-treated sprouts had shorter hypocotyls and roots, negative root tropism and enhanced root branching. The activated glucosinolate production became evident 24 h after the first H2O2 application and continued steadily until harvest. Applying the same treatment to greenhouse-grown wild rocket plants caused scattered leaf bleaching, a certain increase in glucosinolates but decline in phenolics content. The H2O2 treatment of broccoli sprouts caused a 3.5-fold upregulation of APK1, a gene related to sulfur mobilization for glucosinolate synthesis. Comparing the APK1 expression with the competing gene GSH1 using sulfur for antioxidant glutathione production indicated that glutathione synthesis prevailed in the sprouts over the formation of glucosinolates.
... In this perspective, they are immature seedlings composed of two cotyledons, hypocotyl and radicle. Sprouts typically exhibit nutritional superiority as compared to seeds, and enhanced bioactive compound content as compared to their mature counterparts [2][3][4]. In recent years, their consumption has been steadily increasing in the context of rising consumer awareness for healthy diet benefits [2,5]. ...
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: Broccoli sprouts are rich in health-promoting bioactive compounds. Their content depends on both cultivation light quality and temperature. However, these effects have been previously addressed in isolation. Here, the dual inputs of cultivation light quality [blue (B), red (R), mixture of R and B (R+B), mixture of R and UVA (R+UVA)] and air temperature (15, 19, and 23 ◦C) on determining growth, external quality, and the cotyledon and hypocotyl content of five major bioactive compounds were investigated. The carbohydrate status at harvest and postharvest ratio of variable to maximum fluorescence (Fv/Fm) were also assessed. Hypocotyl length was generally enhanced under monochromatic light (R or B) and elevated temperature. Total phenolic, total flavonoid, and glucoraphanin contents were generally higher in cotyledon as compared to hypocotyl. Hypocotyl anthocyanin, total phenolic, total flavonoid, and ascorbic acid contents were generally enhanced by R+B, and were decreased by R. Cotyledon content in these metabolites was generally stimulated by B, and reduced under R or R+UVA. Temperature affected metabolite content depending on the metabolite, organ, and light quality. Lower temperatures, R (23 ◦C) or R+UVA (15, 19, and 23 ◦C) were associated with decreased postharvest Fv/Fm. In conclusion, low cultivation temperature (<23 ◦C), as well as R or R+UVA ought to be avoided. Instead, B and R+B are suitable, with B being preferable, owing to better external quality and enhanced metabolite content in cotyledon which generally holds higher content than hypocotyl.
... This has also been observed for nitrogen and sulphur fertilisation in Brassica rapa (turnip) (Aries et al., 2006;Li et al., 2007). Environmental stresses, such as temperature and light conditions have also been reported to exert a significant influence on glucosinolates content (See Ciska et al., 2008;Pereira et al., 2002;Perez-Balibrea et al., 2008;Ciska et al., 2000 andCharron andSams, 2004). This has also been documented for water stress and aphid feeding, which have been reported to alter the GSLs content in Arabidopsis thaliana (mouse-ear cress) (Mewis et al., 2012). ...
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Radish (Raphanus sativus L.) is a root vegetable with Glucosinolates (GSLs), which is a secondary metabolite that has conducive to human health and promotes anti-inflammatory and anticancer activities in cells. We conducted a study to determine if irrigation timing has an impact on the GSL properties and pungency of two radish cultivars from Ladakh, which are locally called Gya Labuk and Tsentay Labuk. The four irrigation timing as the morning (6.00 AM), noon (12.00 P M), and evening (4.00 PM) and control (anytime) irrigated twice a week. The GSL profile of roots and leaves was done using High Pressure Liquid Chromatography (HPLC). Through this process, we identified nine GSL compounds in root and leaf of radish, which included five that were aliphatic and four that were indole glucosinolate compounds. The most abundant GSL in radish root and leaf was Glucoraphasatin (GRH), which accounts for 89.38-89.51% and 74.85-88.58%of the total GSL in the two cultivars grown in Ladakh i.e. Gya Labuk and Tsentay Labuk respectively. The total GSL ranged from 120.12 ± 4.89 to225.22 ± 79.77 µmol g-1 in Gya Labuk root and 121.17 ± 6.79 to 296.68 ± 23.53 µmol g-1 in Tsentay Labuk root. The GRH value ranged from 46.43 ± 13.52 to 174.94 ± 8.71 µmol g-1 in the leaves of Gya Labuk and ranged from 64.82 ± 5.70 to 149.12 ± 7.09 µmol g-1 in the leaves of Tsentay Labuk. In our investigation, we found that noon irrigated radish had higher total GSL content in both root and leaves as compared to ones irrigated at other times. We also found that dark coloured radish (Gya Labuk) root had a lower concentration of GSL than light coloured ones (Tsentay Labuk). The highest GSL was observed in Tsentay Labuk with light coloured roots while the low GSL was in Gya Labuk with dark pink coloured root.
... On the other hand, Brassicaceae sprouts are generally harvested and marketed at 7-8 days of age after germination, considering that this young physiological state is optimal for consumption in terms of biomass and size. It allows manipulation, as well as concentrates a higher content of health-promoting compounds since sprouts have significantly greater concentrations of phytochemicals than mature plants (10-100 times) [72][73][74]. ...
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Vegetable sprouts are a food source that presents high content of bioactive compounds which can also be enhanced through elicitation mechanisms. To better understand the scientific production and research trends on this topic, a bibliometric analysis by means of the Web of Science database was carried out. The results showed significant growth in research on the elicitation of edible plants sprouts. The three most productive journals were the Journal of Agricultural and Food Chemistry, followed by Food Chemistry and LWT-Food Science and Technology. The co-occurrence of keyword analysis of the different authors showed that the main research topics in this domain were ‘germination’, ‘antioxidant activity’, ‘sprouts’, ‘glucosinolates’ and ‘phenolics‘. The countries with the highest number of scientific publications were China, followed by India and USA. The productivity patterns of the authors conformed to Lotka’s law. This study provides an overview of research on elicitation to enrich bioactive compounds in sprouts, and the need to review and update the trends on this subject.
... Among the environmental factors, light is one of the most important variables that affects phytochemical concentrations in plants. Light conditions influence the morpho-physiology of microgreens, together with the biosynthesis and accumulation of phytochemicals [56][57][58]. According to Mou and Ryder [10], the lower nutritional value of some varieties is due to the marked enclosure of their leaves in the head structure as most of the edible head structure portion includes leaves that are not exposed to light. ...
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Interest in the cultivation of lettuce landraces is increasing because native varieties, as high-quality products, are particularly attractive to consumers. Lettuce is a popular leafy vegetable worldwide, and interest in the consumption of first leaves (microgreens) and seedlings (baby leaves) has grown due to the general belief that young plants offer higher nutritional value. The content of some bioactive compounds and antioxidants (chlorophylls, carotenoids, anthocyanins, ascorbic acid, phenols, antioxidant activity) was monitored in six lettuce landraces and five commercial varieties, and compared across three development stages: microgreen, baby, and adult. Ascorbic acid and phenolic contents were 42% and 79% higher, respectively, in the early stages than in adult lettuces, and red-leaf varieties (CL4 and L11) stood out. This finding agrees with lettuce’s marked antioxidant capacity and correlates with its pigment contents, especially anthocyanins. The nutritional value of adult lettuce is conditioned by its size, shape, and head structure as phytochemical concentrations are regulated by light. The low content of ascorbic acid, phenolics, and anthocyanins in crisphead lettuce (CL5) is a clear example (49, 67%, and 27% lower, respectively, than the adult mean). Our results indicate the wide variability of lettuces’ nutritional characteristics and emphasize that traditional varieties are a helpful source of agricultural biodiversity.
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Broccoli sprouts are rich in secondary metabolites, especially glucosinolates (GLs). The synthesis of GLs can be modified by light. In this study, extractive electrospray ionization-mass spectrometry (EESI-MS) was used to analyze the broccoli sprouts extracts (BSE) under different light quality treatments. Multivariable statistical methods were used to analyze the difference of different light quality treatments. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the gene expression of key enzymes in the aliphatic-GLs biosynthesis pathway. Nineteen compounds, including 7 GLs, 3 phenolic acids, 6 amino acids and 3 organic acids were simultaneously detected in one minute by EESI-MS. Relative expression of MYB28, BCAT4, CYP79F1, CYP83A1 and AOP3 were mostly upregulated in R5B5 (light ratios of red/blue 5:5) treatment. These findings suggest that blue light improving the accumulation of secondary metabolites in broccoli sprouts, and the R5B5 treatment was most beneficial. Furthermore, we established EESI-MS method to simultaneous and rapid detection of secondary metabolites in broccoli sprouts, especially GLs. This study could provide a reference for selecting proper LED lighting conditions to produce broccoli sprouts with high content of bioactive components, and provides light regulation technology and theoretical basis for the industrialized production of sprouts.
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The phytochemical and antioxidant properties of mature (head stage) Chinese cabbage (Brassica rapa ssp. pekinensis) are known; however, data on the phenolic profile, vitamin C (L-ascorbic acid) content and antioxidant capacity of its fresh sprouts are lacking. Since the human consumption of fresh cruciferous sprouts has significantly increased in recent years, their nutritional characterization has become a somewhat urgent matter. Therefore, in this study the contents of total phenolics, flavonols and hydroxycinnamic acids were measured spectrophotometrically, whereas individual flavonoids, phenolic acids and vitamin C were identified and quantified using a newly-developed high performance liquid chromatography method. Also, the antioxidant capacity of five Chinese cabbage sprout growth stages was determined. These stages contained either cotyledons only (seedlings), cotyledons and two leaves, four leaves, six leaves, or ten leaves. Principal component analysis (PCA) and hierarchical clustering (HC) were implemented in order to visualize the classification trend between the stages. Seedlings contained more sinapic acid and vitamin C than older plants. Plants containing six or ten leaves had more ferulic acid and isorhamnetin than younger ones. Total phenolics, flavonols, hydroxycinnamic acids, quercetin and antioxidant capacity did not statistically differ between seedlings and stages with six or ten leaves and their concentrations were significantly higher than in stages with two or four leaves. PCA and HC confirmed the higher phytochemical similarity between seedlings and plants with six or ten leaves than plants with two or four leaves. Therefore, Chinese cabbage seedlings and plants with six or ten leaves should be preferred over plants with two or four leaves, which were ultimately shown to be of lesser nutritional quality.
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In this study, various LED lights (white, red, yellow, green, blue and purple) were applied to evaluate their effects on the biochemical parameters, aliphatic glucosinolates synthesis and sulforaphane formation in broccoli sprouts. The length of broccoli sprouts and bulk water content were decreased after LED light treatments, especially white, green, and purple LED lights. The highest contents of ascorbic acid and anthocyanins were recorded in blue LED light treated broccoli sprouts. Green LED light treated sprouts contained the highest contents of ATP, ADP and AMP. Yellow and bule lights resulted in higher glucose content. Yellow, blue, and purple LED lights induced glucoraphanin and glucoerucin accumulation via upregulating aliphatic glucosinolates biosynthetic genes. Yellow LED light caused higher glucoraphanin content than blue LED light, while sulforaphane formation showed no difference; which might be attributed to higher myrosinase activity and its expression as well as lower ESM1 expression under blue LED light.
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The utilization of rapeseed meal in food is limited due to its abundant glucosinolates (GLs). In this study, an LC-MS/MS method for GLs determination in rapeseed meal was developed. Then, the degradation of GLs using rapeseed sprouts derived myrosinase (MYR) was investigated. Results showed that 11 kinds of GLs were identified in rapeseed meal. The LC-MS/MS method had a high linearity (R² greater than 0.9999), repeatability (RSD < 5%) and recovery rate (92%-102%). The optimum condition for hydrolyzing GLs in rapeseed meal was reacting for 4 h with the addition of 2236.35 U/g MYR, 9.63 μg/g ascorbic acid and 26.68 μg/g EDTA. Under this condition, more than 80% of GLs were degraded and the yields of isothiocyanates and oxazolidinone-2-thione were 859.30 μg/g and 685.59 μg/g, respectively. To conclude, this study reported a reliable method for GLs determination and an effective way to degrade GLs in rapeseed meal.
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The aim of this study was to evaluate the effect of white, red, green, yellow, blue and purple LED lights on visual and nutraceutical quality of broccoli florets during storage at 20 °C for 5 days. The results showed that purple LED light exhibited the best effect on reducing yellowing and retaining chlorophyll via down-regulating expression of genes related to chlorophyll degradation, including BoSGR, BoPAO, BoNYC1 and BoRCCR. On the other hand, yellow, blue and purple LED light increased contents of total phenolic and carotenoids compared to darkness. The highest glucoraphanin content was recorded in purple LED light treated broccoli florets, which was supported by the enhanced expression levels of genes related to glucoraphanin biosynthesis. Meanwhile, purple LED light promoted myrosinase activity and its expression, and reduced ESP expression; thus enhanced sulforaphane formation. In conclusion, among all LED lights, purple LED light showed a significant positive effect considering all estimated indicators and would be useful to maintain and improve the quality of broccoli during storage at 20 °C.
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Technological advancements in light-emitting diode (LED) technology have led to the production, under controlled indoor conditions, of value-added crops that are high in nutritional or nutraceutical contents. In this study, the growth and glucosinolate (GSL) profiles of a common Asian vegetable, Brassica rapa subsp. chinensis var. parachinensis (choy sum or cai xin) were determined under LED lighting. The growth of choy sum was influenced by both the LED light intensity and spectrum, with plants grown under 160 μmol m⁻² s⁻¹ red-blue light (160RB) producing the highest shoot biomass (∼100–300 % increment in adult plants). GSL content was found to vary across growth stages regardless of LED treatment. Total GSLs per gram fresh weight were four times higher in one-leafed seedlings than in adult plants. A shift from a high proportion of aliphatic GSLs in one-leafed seedlings to indolic and aromatic GSLs in three-leafed seedlings and adult plants was attributed to an increase in the proportion of glucobrassicin and/or 4-hydroxy-glucobrassicin, and gluconasturtiin which are known to have anti-cancer properties. Our results will be useful for the production of GSL-enhanced vegetables through urban farming.
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The study is based on the field experiment, carried out between 2009-2012 in Żyznów, in randomized blocks with 3 replications. The factors of experiment were, firstly the varieties of sweet potato: Carmen Rubin, Goldstar, White Triumph, and secondly the three various cultivation technologies: a) traditional farming method without protection, b) cultivation with use of PE-foil, c) cultivation with use of PP-non-woven fabric. The level of fertilization was kept on the constant level. The cultivation with use of protection caused brightening of the apical part, both the stolon parts, compared with the cultivated in traditional ways. The specific genetic features of different varieties of sweet potato were influencing the browning of flesh of cooked and raw potatoes.
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Sprouting process enhances plant bioactive compounds. Broccoli (Brassica oleracea L) sprouts are well known for their high levels of glucosinolates (GLs), amino acids, and antioxidants, which offer outstanding biological activities with positive impact on plant metabolism. elevated CO2 (eCO2, 620ppm) was applied for 9 days to further improve nutritive and health-promoting values of three cultivars of broccoli sprouts i.e., Southern star, Prominence and Monotop. eCO2 improved sprouts growth and induced GLs accumulation e.g., glucoraphanin, possibly through amino acids production e.g., high methionine and tryptophan. There was increases in myrosinase activity, which stimulated GLs hydrolysis to yield health promoting sulforaphane. Interestingly low levels of ineffective sulforaphane nitrile was detected and positively correlated with reduced epithiospecifier protein after eCO2 treatment. High glucoraphanin and sulforaphane levels in eCO2 treated sprouts improved anticarcinogenic and anti-inflammatory properties of their extracts. In conclusion, eCO2 treatment enrich broccoli sprouts with health promoting metabolites and bioactivities.
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In 2009–2011 there was investigated the effect of Asahi SL on crop and chemical composition of some potato cultivars: Denar, Irys, Satina. Studies were carried out in field experiment station in the central-eastern part of Polish on the soil of light loamy sand content. The experiment was set by the means of randomized sub-blocks in dependent system. The primary factors were: sub-blocks with Asahi SL; control group with distilled water. The secondary factors were three potato cultivars. Growth regulator Asahi SL contributed to the increase in the total yield and commercial tuber yield by modifying the structure. Asahi SL caused the increase of total and commercial crop of tubers as well as phenolic compounds content. The content of starch and vitamin C did not change, and levels of soluble, reductive sugars and sacharose decreased under this synthetic growth regulator influence. Among investigated varieties the most prolific was very early cultivar – Denar, the least prolific – middle early Satina. The highest levels of starch, soluble and reductive sugars as well as vitamin C was characterized Satina cultivar, the highest concentration of sacharose – Irys, and the phenolic compounds – Denar. The reaction of investigated varieties towards Asahi SL application – regarding the soluble, reductive sugars, sacharose, vitamin C and phenols – was differentiated . It was found positive interaction of this preparation with the crop and its quality. The most prolific cultivar appeared to be Denar, the richest in analyzed compounds – Satina.
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Postharvest losses of whole and fresh‐cut fruits and vegetables cause significant reductions in food availability and an increase in economic losses/damages. Additionally, regulatory agencies are increasingly restricting the postharvest use of synthetic chemicals. This has strengthened the need to develop environmentally friendly approaches to postharvest management, such as utilization of natural compounds, antagonist microorganisms, and treatments with abiotic stresses, among others. The current review focuses on the potential of low doses of abiotic stresses to extend the shelf life, increase the amount of health beneficial phytochemicals, and reduce postharvest losses of fresh produce. The positive effects of the responses to low doses of abiotic stresses are based on a biological phenomenon termed hormesis. Research to develop new technologies to improve postharvest handling of fresh fruit and vegetables as well as minimally processed products is critical. The phenomenon of abiotic stress hormesis in fresh fruit and vegetables shows the potential not only to enhance defense compounds that could reduce diseases during postharvest storage and extend shelf life but also to elevate the content of health‐promoting substances. The beneficial effects of UV‐C hormesis have been extensively investigated in numerous types of fresh produce. However, our knowledge on hormesis exhibited by other abiotic stresses is still limited. Hence, the objective of this review is to discuss the relevance of hormesis for postharvest research by examining whether all abiotic stresses exhibit the phenomenon, its biological significance, the potential application in various commodities, and how it may direct the future of postharvest research.
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Six different cultivars of broccoli were analyzed for the major antioxidant phytochemicals. Significant differences (p < 0.05) were observed amongst the cultivars for vitamin C, beta-carotene, lutein, a-tocopherol and phenolic contents at edible maturity stage. Vitamin C content ranged from 25.5 to 82.3 mg/100 g; maximum was in 'NS-50' (82.3 mg/100 g) and 'Lucky' had minimum (25.5 mg/100 g). The beta-carotene and lutein contents ranged from 0.48 to 1.13 mg/100 g and from 0.41-1.02 mg/100 g, respectively. Vitamin E (alpha-tocopherol) content ranged from 0.22 to 0.68 mg/100 g; maximum tocopherol was in 'Sultan' (0.68 mg/100 g). The phenolic content ranged from 44.5 to 82.9 mg/100 g; maximum was in 'Sultan' (2.9 mg/100 g) and minimum in 'Hybrid No.2' (44.5 mg/100 g).
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Broccoli (Brassica oleracea L. var. italica cv. Marathon) sprouts are a rich source of glucosinolates, particularly 4-methylsulfinylbutyl glucosinolate (glucoraphanin), the precursor of the chemoprotective isothiocyanate, sulforaphane. Sulfur and nitrogen fertilization have been shown to influence the pattern and levels of glucosinolates in mature broccoli, but little information is available on the fertilization of sprouts, a transient stage of broccoli growth, which have been recommended for salads. Therefore, an experiment was set up to evaluate the effect of N and S fertilization on the glucosinolate content of the aerial part and roots of broccoli sprouts. Nitrogen was tested at 0, 45.5, 91.0 mg L−1 and sulfur at 0, 14.6 and 29.2 mg L−1. The results showed that total glucosinolates in the aerial part were significantly higher (P < 0.001) than in the roots. The major glucosinolates in the aerial part were 4-methylsulfinylbutyl and 3-methylsulfinylpropyl whereas in the roots they were 2-phenylethyl and 4-methylthiobutyl. Fertilization of broccoli sprouts had a significant (P < 0.001) detrimental effect on the levels of aliphatic glucosinolates whereas the opposite was noted for indole and aromatic glucosinolates, for some of the fertilization combinations tested. Overall, the results indicate that broccoli sprouts do not benefit from fertilization. Copyright © 2006 Society of Chemical Industry
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Antioxidant phytochemicals such as vitamin C, β-carotene, lutein, α-tocopherol, and total phenolics were estimated in fresh samples at the edible maturity stage in different genotypes of cruciferous vegetables using a reverse-phase HPLC system. Maximum mean vitamin C (52.9 mg/100 g), β-carotene (0.81 mg/100 g), lutein (0.68 mg/100 g), dl-α-tocopherol content (0.47 mg/100 g) and phenol content (63.4 mg/100 g) was recorded in broccoli. Results indicate that the cruciferous vegetables are a relatively good source of abundant antioxidants, and there is a substantial and significant variation, both within and between the subspecies, for the antioxidant phytochemicals.
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Seeds, of either commercial crucifer crops or some wild and weed relatives, were screened for intact glucosinolates using a previously developed ion-pair LC-MS method. This method, in contrast to GC-MS techniques, ensures the accurate measurement of all classes of glucosinolates. Many crucifer seeds contained very high concentrations of glucosinolates with low concentrations of additional pigments and secondary metabolites. The other common seed metabolites were cinnamoylcholine esters, for example, sinapine. Glucosinolates derived from homologues of l-methionine were characteristic of Brassica and related crucifer species. In addition, significant concentrations of 4-hydroxy-3-indolylmethylglucosinolate were found in the majority of Brassica species. Wild and weed species often had relatively simple glucosinolate profiles: either a single glucosinolate or a predominant glucosinolate together with trace amounts of others. Species identified with seed glucosinolate profiles suitable for purification included various Alyssum, Erysimum, and Iberis species for 3-methythiopropyl-glucosinolate and 3-methylsulfinylpropyl-glucosinolate and various Alyssum, Erysimum, and Lepidium species with very high concentrations of C4-C6 aliphatic glucosinolates. Seeds of Arabis, Barbarea, Lepidium, Moringa, and Sinapis species were good sources of aromatic glucosinolates, and Azima tetracantha was a good source for N-methoxy-3-indolylmethyl-glucosinolate. MS data are reported for all of the intact glucosinolates detected from the screening process.
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The importance of dietary sulforaphane in helping maintain good health continues to gain support within the health-care community and awareness among U.S. consumers. In addition to the traditional avenue for obtaining sulforaphane, namely, the consumption of appropriate cruciferous vegetables, other consumer products containing added glucoraphanin, the natural precursor to sulforaphane, are now appearing in the United States. Crucifer seeds are a likely source for obtaining glucoraphanin, owing to a higher concentration of glucoraphanin and the relative ease of processing seeds as compared to vegetative parts. Seeds of several commonly consumed crucifers were analyzed not only for glucoraphanin but also for components that might have negative health implications, such as certain indole-containing glucosinolates and erucic acid-containing lipids. Glucoraphanin, 4-hydroxyglucobrassicin, other glucosinolates, and lipid erucic acid were quantified in seeds of 33 commercially available cultivars of broccoli, 4 cultivars each of kohlrabi, radish, cauliflower, Brussels sprouts, kale, and cabbage, and 2 cultivars of raab.
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In pot experiments under controlled conditions we investigated the effects of water stress on oilseed rape. Yield and yield components were mainly affected by water shortage occurring from flowering to the end of seed set. The greatest reduction (48%) was observed when only 37% of full water requirement was supplied to the plant during this stage. The number of seeds per plant was the main yield component affected. Some compensation occurred when the water supply was restored. The 1000-seed weight was only affected by a water stress from the stage when the pods were swollen until the seeds colored stage. The results demonstrated a marked reduction in oil concentration when water deficit occurred from anthesis to maturity. There was an inverse relationship between oil and protein concentration. The most marked effect observed in this experiment was on the glucosinolate concentration where increases of up to 60% were observed. These results may explain effects on seed quality of field grown oilseed rape.
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In previous studies it was shown that the concentration of total and individual glucosinolates in brassicaceous plants can vary significantly over a 24-h period grown either in the field or under controlled conditions. The present study shows total and individual glucosinolate variation during a single day. Seedlings of cabbage grown under controlled conditions and at 14 and 15 days after emergence were moved to 20°C (Exp A) and 30°C (Exp B), with a constant photosynthetic photon flux density of 480 μmol m−2 s−1 and 75% relative humidity, over a 2-day period, during which time aerial parts and roots were sampled at regular intervals. Whilst the glucosinolate patterns of the aerial part of the plant and of the roots remained the same, the levels of major glucosinolates in the aerial part, averaged over all sampling times and 2 days, were 233 ± 60 μmol 100 g−1 DW for 3-methylsulphinylpropyl and 72 ± 22 for 2-propenyl; in the roots, 2-phenylethyl and 1-methoxyindol-3-ylmethyl showed the highest average concentrations, with 678 ± 355 μmol 100 g−1 DW and 411 ± 122, respectively. Total and individual glucosinolate levels showed very high significant differences between the two plant parts. Despite the constant temperature, light and relative humidity, glucosinolates varied within a 24-h period, showing ultradian rhythms that are common to several metabolic processes in plants. The results confirm previous observations that at a temperature of 20°C, close to the optimum for growth and development, the diurnal variation in glucosinolate concentration, was smaller than at 30°C. © 1998 Society of Chemical Industry
Article
In the Iberian Peninsula, Brassicacrops are grown throughout the year and may be consumed at immature stages or leaves may be harvested by ‘picking-over’ during plant growth. Consumption of Brassicas in Portugal is high but there is no information on the levels of glucosinolates in such material. Changes in the total and individual glucosinolate concentrations of fourBrassica oleraceatypes (two cultivars of Portuguese cabbage, one Portuguese kale type and one hybrid white cabbage) and one PortugueseBrassica napustype were monitored throughout two growing seasons, spring/summer (SS) and summer/winter (SW). Glucosinolates were determined between sowing and maturity corresponding to nine sampling dates in the leaves and five harvests in the heads. The main glucosinolates inB oleraceatypes were 3-methylsulphinylpropyl-, allyl- and indol-3-ylmethyl- whereas in theB napustype pent-4-enyl-, 2-hydroxybut-3-enyl- and but-3-enylglucosinolate predominated. In the leaves ofB oleraceatypes, the highest concentration of total glucosinolates and of most of the individual glucosinolates was observed at 14 days after sowing whilst, in the heads the highest levels were noted at the start of head formation. In theB napus, the highest total and individual glucosinolate concentration was generally observed at the end of the growing season. Both for the total and for the main individual glucosinolates there were significant differences (P<0·001) between the nine harvest dates and between growing seasons. Between the two seasons, the glucosinolate levels in SS were generally higher than in SW. A comparison of cultivars showed the hybrid cabbage to have generally higher glucosinolate levels than the Portuguese types, except forB napus.
Article
Clear influence of N and S applications on the profile of individual glucosinolates in the seeds of winter oilseed rape (Brassica napus L) was found in field experiments. The major effect of N was on the relative abundance of the four alkenyl glucosinolates. Increasing the N rate increased the relative proportion of 2-hydroxybut-3-enyl at the expense of pent-4-enyl, and to a lesser extent, 2-hydroxypent-4-enyl, in the double-low (low erucic acid and low glucosinolates) variety Cobra, but at the expense of but-3-enyl in the single-low (low erucic acid) variety Bienvenu. The results strongly suggest that a high N supply favours the hydroxylation step from but-3-enyl to 2-hydroxybut-3-enyl. In contrast, the major effect of S appeared to be on the relative abundance of the alkenyl and indole groups as a whole. Sulphur deficiency decreased the concentrations of the alkenyl glucosinolates more than those of the indole glucosinolates, whereas S application to a S-deficient crop resulted in a larger response in the alkenyl group than in the indole group. The more sensitive response of alkenyl glucosinolates to the plant S status is probably due to the requirement of methionine in their biosynthesis, as compared with the indole glucosinolates which are derived from tryptophan. Implications for changes in the glucosinolate profile in rapeseed are discussed.
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Many secondary metabolites found in plants have a role in defence against herbivores, pests and pathogens. In this review, a few examples are described and discussed, and some of the problems in determining the precise role(s) of such metabolites highlighted. The role of secondary metabolites in defence may involve deterrence/anti-feedant activity, toxicity or acting as precursors to physical defence systems. Many specialist herbivores and pathogens do not merely circumvent the deterrent or toxic effects of secondary metabolites but actually utilize these compounds as either host recognition cues or nutrients (or both). This is true of both cyanogenic glucosides and glucosinolates, which art discussed in detail as examples of defensive compounds. Their biochemistry is compared and contrasted. An enormous variety of secondary metabolites are derived from shikimic acid or aromatic amino acids, many of which have important roles in defence mechanisms. Several classes of secondary products are ‘induced’ by infection, wounding or herbivory, and examples of these are given. Genetic variation in the speed and extent of such induction may account, at least in part, for the difference between resistant and susceptible varieties. Both salicylates and jasmonates have been implicated as signals in such responses and in many other physiological processes, though their prescise roles and interactions in signalling and development are not fully understood.
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Leafy salad species are increasingly consumed in the human diet and there is increased concern about the levels of microbial organisms in these raw foods, and especially bacteria such as Salmonella that cause food poisoning. Various chemical sanitizers therefore are used to control microorganisms and fungi, but there is very little information on the effects of these chemicals on food composition. Wild rocket (Diplotaxis tenuifolia L. DC) leaves were washed using tap water, chlorine (100 mg L−1), ozonated water (10 mg L−1), lactic acid (Purac® 20 mL L−1), acidified sodium chlorite (Sanova® 250 mg L−1) and peroxyacetic acid (Tsunami® 300 mg L−1). The effects of sanitizers on the contents of Vitamin C, polyphenols and glucosinolates of rocket leaves were studied under air and low O2 (1–3 kPa) + high CO2 (11–13 kPa) for 15 days at 4 °C. All the sanitizers effectively reduced microbial growth on the day of processing, but only Purac, Tsunami and Sanova inhibited the microbial growth throughout the shelf life. The visual quality was acceptable for all treatments in air while it was poor under low O2 + high CO2. In addition, Purac was particularly detrimental for sensory quality. Both chlorophyll a and chlorophyll b contents were reduced throughout storage but were independent of washing treatments and storage conditions. The content of vitamin C was maintained for up to 8 days of storage under air and low O2 + high CO2, but Purac washes markedly reduced the vitamin C content. A clear decrease in ascorbic acid followed by an increase in dehydroascorbic acid was observed when samples were stored under low O2 + high CO2. The content of flavonoids was not affected by the washing solutions on the processing day and remained almost constant throughout the storage in air. However, marked reductions were observed when samples were stored under low O2 + high CO2. The glucosinolates were the most affected constituents of rocket leaves as the content was reduced from 4 to 33% when samples were stored in air while the decrease was between 60 and 100% in low O2 + high CO2. These data revealed that Sanova and Tsunami could be alternative sanitizers to chlorine for rocket leaf washes due to good retention of sensory quality with no detrimental reduction of the antioxidant constituents.
Article
Myrosinase catalyzes the hydrolysis of glucosinolates found in the Brassicaceae, generating a variety of bioactive reaction products that may aid in the prevention of some cancers and that are suppressive to soil-borne plant pathogens. Two cultivars each of broccoli (Brassica oleracea L var italica), Brussels sprouts (B oleracea var gemmifera), cabbage (B oleracea var capitata), cauliflower (B oleracea var botrytis), and kale (B oleracea var acephala) were grown during two fall seasons and two spring seasons to determine if myrosinase activity varied by season. Regression models that included mean temperature and photosynthetic photon flux (PPF) during the growing seasons showed that climatic variables explained seasonal differences for myrosinase activity. Activity-FW (FW = fresh weight; U g−1) and specific activity (U mg−1) were significantly (p ≤ 0.05) affected by season, botanical group and group × season. Activity-FW had a negative linear relationship with temperature, and a positive linear but negative quadratic relationship with PPF. Specific activity had a positive linear and a negative quadratic relationship with both temperature and PPF. Therefore the influence of climatic factors on myrosinase activity in Brassica species may affect the potential benefits of the glucosinolate–myrosinase system. Copyright © 2004 Society of Chemical Industry
Article
The effects of light illumination on the ascorbic acid content and growth of soybean sprouts were investigated. Among the six light qualities studied, ultraviolet light had the highest promoting effect on the ascorbic acid content in soybean sprouts, increasing it by 77.0% compared with the darkness control, while red light had the highest promoting effect on the growth of soybean sprouts, increasing the total fresh weight by 16.6% compared with the darkness control. Experiments with different durations of ultraviolet and red light illumination in a day showed that 12 h ultraviolet (500 Lx) and 12 h red (1000 Lx) light diurnal cycles had the highest promoting effects on both the ascorbic acid level and fresh weight of soybean sprouts, increasing the ascorbic acid content and total fresh weight by 78.7 and 17.4% respectively compared with the darkness control. The results indicated that germination of soybeans under 12 h ultraviolet and 12 h red light diurnal cycles was an effective process for increasing the yield and enhancing the nutritional quality of soybean sprouts. Copyright © 2005 Society of Chemical Industry
Article
Broccoli (Brassica oleracea L. var. Italica) is a recognised health-promoting vegetable, which is moderately sensitive to salinity. In this study, the primary response of broccoli plants (cv.Marathon) to salinity has been characterised. For this, leaf water relations, nutrient composition, root hydraulic conductivity (L 0) and the effect of mercury (an aquaporin blocker) on L 0 were determined for plants grown with 0, 20, 40, 60, 80 or 100mM NaCl for 2weeks. During the 2weeks of treatment, the plants showed a two-phase growth response to salinity. During the first phase (1week), growth reduction was high, probably related to water stress as no osmotic adjustment occurred and reductions of L 0, the mercury effect and Gs were observed. After 2weeks, the growth reduction could have resulted from internal injury caused by Na+ or Cl−, since osmotic adjustment was achieved and water relations plus the mercury effect were re-established to a high degree, indicating high aquaporin functionality. The fact that aquaporin functionality fits well with the overall water relations response is very relevant, since the two-phase adaptation to salinity may imply two types of aquaporin regulation.
Article
Soybeans (Glycine max (L.) Merill) are popularly known as a healthy food in many Asian countries and are mostly consumed as soymilk, tofu, and fermented products such as miso, temph, and sufu. The objective of this study was to determine the variation and composition of phenolic compounds and isoflavone contents in soybean seeds [Glycine max (L.) Merill] and sprouts [Kongnamul] grown under dark conditions (producing yellow soybean sprouts) and in green and yellow boxes (producing green soybean sprouts). In seven soybean cultivars, the total phenolic content ranged from 6.67μg−1 in Pureunkong to 72.33μg−1 in Poongsannamulkong. The average total phenolic content in the green soybean sprouts (48.33μg−1) was higher than in the yellow soybean sprouts (29.75μg−1). The total phenolic content in the yellow soybean sprouts varied from 9.88μg−1 to 47.71μg−1, and the total phenolic content in the green soybean sprouts varied from 29.21μg−1 to 79.70μg−1. Only four phenolic compounds, p-hydroxybenzoic acid, salicylic acid, p-coumaric acid, and ferulic acid, were detected in all soybean cultivars. Syringic acid was not detected in yellow soybean sprouts, and myricetin was only detected in yellow soybean sprouts (4.65μg−1) from the Pureunkong cultivar grown under dark conditions. The total isoflavone content in soybean seeds ranged from 2.1μg−1 in Sowonkong to 33.0μg−1 in Pureunkong, and the mean total isoflavones was 10.61μg−1. Green soybean sprouts had higher average total isoflavones (1389.4μg−1) than yellow soybean sprouts (559.2μg−1), and the total isoflavone content was highest in the Pureunkong yellow soybean sprouts (756.3μg−1) and the Sowonkong green soybean sprouts (2791.6μg−1). In soybean sprouts, the higher the (malonyl)-daidzin or (malonyl)-genistein content, the higher the total isoflavone level. Our study suggests that producing soybean sprouts enriched in isoflavones under coloured-light sources is feasible.
Article
 The changes in the quantities of inositol phosphates during the maturation and germination of pea, faba bean and lupin seeds were determined in two consecutive (1993 and 1994) years of differing weather conditions. Irrespective of the year, all seeds accumulated predominantly inositol hexaphosphate (IP6). The weather conditions influenced the accumulation of inositol phosphates in maturing seeds, but they did not influence the total content. Gradual degradation of inositol phosphates occurred during seed germination. After 8 days of germination, IP6 was degraded by some 80% in peas, 78% in faba beans and 42% in lupin seeds. The enzymic hydrolysis of higher forms of inositol phosphates (IP6 and IP5) in germinating seeds was assumed to yield inositol tetraphosphate (IP4) and inositol triphosphate (IP3), because the quantities of these compounds increased during seed germination.
Article
Total aliphatic and indole/aromatic glucosinolates and vitamin C content (ascorbic+dehydroascorbic acid) were evaluated in the edible portions of fresh harvested broccoli (Brassica oleracea L. var. italica) florets (Marathon cv.) before and after cooking and in the cooking water. High pressure boiling, steam cooking, microwaving and low pressure boiling (conventional) were the four domestic cooking processes used in this work. Results showed great differences among the four cooking processes and their influence on the content of glucosinolates and vitamin C. Thus, clear disadvantages were detected when cooking in a microwave due to the high loss of vitamin C (40%) and total glucosinolates (74%) in comparison with the rest of treatments. High pressure and conventional boiling had a significant loss rate of total glucosinolates (33% and 55% respectively) regarding fresh raw broccoli, due to the leaching into the cooking water. On the other hand, steaming had minimal effects on glucosinolates and vitamin C. Therefore, we can conclude that a large quantity of glucosinolates and vitamin C will be consumed in steamed broccoli when compared to the other cooking processes.
Article
The discovery of bioactive components in foods is exciting, suggesting the possibility of improved public health through diet. Yet the content of bioactive components in plant food varies, making quality control and intake recommendations problematic. Variation in content of bioactive components in fruits and vegetables depends upon both genetics and environment, including growing conditions, harvest and storage, processing and meal preparation. Cruciferous vegetables, which contain both anticarcinogenic and antioxidant properties, are excellent examples to illustrate the problem in assessing health benefits of foods that vary in content of bioactive components. In broccoli, the content of both glucosinolates and their bioactive hydrolysis products varies with genotype, environment and processing. Antioxidant vitamins and flavonoid content varies also. Here we review the influences of genetics, environment and post-harvest processing on content of bioactive components in broccoli, an area that is presently only partly understood. Reporting a range for bioactive component content can help the public to make informed choices about diet. For the future, research into the mechanisms behind this variation can lead to an understanding of genetic regulation of these variations, resulting in the generation of a consistent supply of nutritionally enhanced plant foods on the market.
Article
The parameters for maintaining visual and nutritional quality in broccoli heads after harvest are well understood, with low temperature maintenance being of paramount importance. Recently, much attention has been focussed on the phytochemicals contained within broccoli, glucosinolates in particular, that may help prevent the onset of certain cancers and cardiovascular disease. Relatively little is known, however, of the effects of commonly used postharvest handling procedures designed to maintain broccoli quality on glucosinolate content. This review looks at the effects of temperature, relative humidity, storage under controlled atmosphere (CA) or modified atmosphere packaging (MAP) and processing on glucosinolate content in broccoli heads. In addition, the significant effect of cooking on glucosinolate content is reviewed. The most important postharvest conditions necessary for maintaining broccoli quality are low temperature (<4 °C) and high relative humidity. These conditions maintain cellular integrity and in the process appear to maintain glucosinolate content by preventing the mixing of glucosinolates with myrosinase. One of the most important processes in the postharvest chain that has the most critical effect on glucosinolates, however, is the cooking method employed, with steaming for 2 min being the most effective way to maintain glucosinolate content.
Article
Induction of phase 2 detoxication enzymes [e.g., glutathione transferases, epoxide hydrolase, NAD(P)H: quinone reductase, and glucuronosyltransferases] is a powerful strategy for achieving protection against carcinogenesis, mutagenesis, and other forms of toxicity of electrophiles and reactive forms of oxygen. Since consumption of large quantities of fruit and vegetables is associated with a striking reduction in the risk of developing a variety of malignancies, it is of interest that a number of edible plants contain substantial quantities of compounds that regulate mammalian enzymes of xenobiotic metabolism. Thus, edible plants belonging to the family Cruciferae and genus Brassica (e.g., broccoli and cauliflower) contain substantial quantities of isothiocyanates (mostly in the form of their glucosinolate precursors) some of which (e.g., sulforaphane or 4-methylsulfinylbutyl isothiocyanate) are very potent inducers of phase 2 enzymes. Unexpectedly, 3-day-old sprouts of cultivars of certain crucifers including broccoli and cauliflower contain 10-100 times higher levels of glucoraphanin (the glucosinolate of sulforaphane) than do the corresponding mature plants. Glucosinolates and isothiocyanates can be efficiently extracted from plants, without hydrolysis of glucosinolates by myrosinase, by homogenization in a mixture of equal volumes of dimethyl sulfoxide, dimethylformamide, and acetonitrile at -50 degrees C. Extracts of 3-day-old broccoli sprouts (containing either glucoraphanin or sulforaphane as the principal enzyme inducer) were highly effective in reducing the incidence, multiplicity, and rate of development of mammary tumors in dimethylbenz(a)anthracene-treated rats. Notably, sprouts of many broccoli cultivars contain negligible quantities of indole glucosinolates, which predominate in the mature vegetable and may give rise to degradation products (e.g., indole-3-carbinol) that can enhance tumorigenesis. Hence, small quantities of crucifer sprouts may protect against the risk of cancer as effectively as much larger quantities of mature vegetables of the same variety.
Article
Broccoli inflorescences have been recognized as components of healthy diets on the basis of their high content of fiber, vitamin C, carotenoids, and glucosinolates/isothiocyanates. Broccoli sprouts have been recently shown to have high levels of glucoraphanin (4-methylsulfinylbutyl glucosinolate), the precursor of the chemoprotective isothiocyanate, sulforaphane. This study evaluated the effects of temperature and developmental stage on the glucosinolate content of broccoli sprouts. Seedlings cultivated using a 30/15 degrees C (day/night) temperature regime had significantly higher glucosinolate levels (measured at six consecutive days postemergence) than did sprouts cultivated at lower temperatures (22/15 and 18/12 degrees C; p < 0.001). Both higher (33.1 degrees C) and lower (11.3 degrees C) constant temperatures induced higher glucosinolate levels in sprouts grown to a uniform size. Glucosinolate levels were highest in cotyledons and lowest in roots of sprouts dissected both early and late in the 11 day developmental span investigated. Nongerminated seeds have the highest glucosinolate levels and concordantly greater induction of mammalian phase 2 detoxication enzymes. Levels decline as sprouts germinate and develop, with consistently higher glucosinolate content in younger developmental stages, independent of the temperature regime. Temperature stress or its associated developmental anomalies induce higher glucosinolate levels, specific elevations in glucoraphanin content, and parallel induction of phase 2 chemoprotective enzymes.
Article
L-Ascorbic acid (AsA) was found to be loaded into phloem of source leaves and transported to sink tissues. When L-[(14)C]AsA was applied to leaves of intact plants of three different species, autoradiographs and HPLC analysis demonstrated that AsA was accumulated into phloem and transported to root tips, shoots, and floral organs, but not to mature leaves. AsA was also directly detected in Arabidopsis sieve tube sap collected from an English green aphid (Sitobion avenae) stylet. Feeding a single leaf of intact Arabidopsis or Medicago sativa with 10 or 20 mM L-galactono-1,4-lactone (GAL-L), the immediate precursor of AsA, lead to a 7- to 8-fold increase in AsA in the treated leaf and a 2- to 3-fold increase of AsA in untreated sink tissues of the same plant. The amount of AsA produced in treated leaves and accumulated in sink tissues was proportional to the amount of GAL-L applied. Studies of the ability of organs to produce AsA from GAL-L showed mature leaves have a 3- to 10-fold higher biosynthetic capacity and much lower AsA turnover rate than sink tissues. The results indicate AsA transporters reside in the phloem, and that AsA translocation is likely required to meet AsA demands of rapidly growing non-photosynthetic tissues. This study also demonstrates that source leaf AsA biosynthesis is limited by substrate availability rather than biosynthetic capacity, and sink AsA levels may be limited to some extent by source production. Phloem translocation of AsA may be one factor regulating sink development because AsA is critical to cell division/growth.
Article
"Bioactive compounds" are extranutritional constituents that typically occur in small quantities in foods. They are being intensively studied to evaluate their effects on health. The impetus sparking this scientific inquiry was the result of many epidemiologic studies that have shown protective effects of plant-based diets on cardiovascular disease (CVD) and cancer. Many bioactive compounds have been discovered. These compounds vary widely in chemical structure and function and are grouped accordingly. Phenolic compounds, including their subcategory, flavonoids, are present in all plants and have been studied extensively in cereals, legumes, nuts, olive oil, vegetables, fruits, tea, and red wine. Many phenolic compounds have antioxidant properties, and some studies have demonstrated favorable effects on thrombosis and tumorogenesis and promotion. Although some epidemiologic studies have reported protective associations between flavonoids or other phenolics and CVD and cancer, other studies have not found these associations. Various phytoestrogens are present in soy, but also in flaxseed oil, whole grains, fruits, and vegetables. They have antioxidant properties, and some studies demonstrated favorable effects on other CVD risk factors, and in animal and cell culture models of cancer. However, because phytoestrogens act both as partial estrogen agonists and antagonists, their effects on cancer are likely complex. Hydroxytyrosol, one of many phenolics in olives and olive oil, is a potent antioxidant. Resveratrol, found in nuts and red wine, has antioxidant, antithrombotic, and anti-inflammatory properties, and inhibits carcinogenesis. Lycopene, a potent antioxidant carotenoid in tomatoes and other fruits, is thought to protect against prostate and other cancers, and inhibits tumor cell growth in animals. Organosulfur compounds in garlic and onions, isothiocyanates in cruciferous vegetables, and monoterpenes in citrus fruits, cherries, and herbs have anticarcinogenic actions in experimental models, as well as cardioprotective effects. In summary, numerous bioactive compounds appear to have beneficial health effects. Much scientific research needs to be conducted before we can begin to make science-based dietary recommendations. Despite this, there is sufficient evidence to recommend consuming food sources rich in bioactive compounds. From a practical perspective, this translates to recommending a diet rich in a variety of fruits, vegetables, whole grains, legumes, oils, and nuts.
Article
Many epidemiological studies have tried to associate the intake of certain food products with a reduced risk for certain diseases. Results of these studies are often ambiguous, conflicting, or show very large deviations of trends. Nevertheless, a clear and often reproduced inverse association is observed between total vegetable and fruit consumption and cancer risk. Examples of components that have been indicated to have a potential protective effect in food and vegetables include antioxidants, allium compounds and glucosinolates. The food production chain can give a considerable variation in the level of bioactive components in the products that are consumed. In this paper the effects of this variability in levels of phytochemicals in food products on the sensitivity of epidemiological studies are assessed. Information on the effect of variation in different steps of the food production chain of Brassica vegetables on their glucosinolate content is used to estimate the distributions in the levels in the final product that is consumed. Monte Carlo simulations of an epidemiological cohort study with 30,000 people have been used to assess the likelihood of finding significant associations between food product intake and reduced cancer risk. By using the Monte Carlo simulation approach, it was shown that if information on the way of preparation of the products by the consumer was quantified, the statistical power of the study could at least be doubled. The statistical power could be increased by at least a factor of five if all variation of the food production chain could be accounted for. Variability in the level of protective components arising from the complete food production chain can be a major disturbing factor in the identification of associations between food intake and reduced risk for cancer. Monte Carlo simulation of the effect of the food production chain on epidemiological cohort studies has identified possible improvements in the set up of such studies. The actual effectiveness of food compounds already identified as cancer-protective by current imprecise methods is likely to be much greater than estimated at present.
Article
Three sulfur (S) treatements were imposed by applying gypsum to three broccoli cultivars (Claudia, Marathon, and TB-234) known to differ in glucoraphanin content of mature seeds. The S treatments were control (very low added S), low S (23 kg S ha(-)(1)), and high S (92 kg S ha(-)(1)). The gypsum applications during the early vegetative phase of the three broccoli cultivars increased S uptake and the glucoraphanin content in each plant organ. There were significant genotypic differences for the content of both S and glucoraphanin in all plant organs at different growth stages with gypsum applications. A large increase in S and glucoraphanin content was found in the green heads of broccoli and mature seeds. S present in glucoraphanin accounted for only 4-10% of total S content in broccoli heads. However, S present in glucoraphanin in mature seeds accounted for 40-46% of the total S in the seeds of moderate and high glucoraphanin cultivars (Marathon and TB-234). The partitioning of S into glucoraphanin also increased with gypsum applications. Differences in S uptake, S distribution between organs, and partitioning of S into glucoraphanin largely explained the differences in glucoraphanin content in the green heads and mature seeds for the three broccoli cultivars and three S treatments.
Article
Vitamin C (L-ascorbic acid) is an important primary metabolite of plants that functions as an antioxidant, an enzyme cofactor, and a cell-signalling modulator in a wide array of crucial physiological processes, including biosynthesis of the cell wall, secondary metabolites and phytohormones, stress resistance, photoprotection, cell division, and growth. Plants synthesize ascorbic acid via de novo and salvage pathways, but the regulation of its biosynthesis and the mechanisms behind ascorbate homeostasis are largely unknown. Jasmonic acid and its methyl ester (jasmonates) mediate plant responses to many biotic and abiotic stresses by triggering a transcriptional reprogramming that allows cells to cope with pathogens and stress. By using 14C-mannose radiolabelling combined with HPLC and transcript profiling analysis, it is shown that methyl jasmonate treatment increases the de novo synthesis of ascorbic acid in Arabidopsis and tobacco Bright Yellow-2 (BY-2) suspension cells. In BY-2 cells, this stimulation coincides with enhanced transcription of at least two late methyl jasmonate-responsive genes encoding enzymes for vitamin C biosynthesis: the GDP-mannose 3″,5″-epimerase and a putative L-gulono-1,4-lactone dehydrogenase/oxidase. As far as is known, this is the first report of a hormonal regulation of vitamin C biosynthesis in plants. Finally, the role of ascorbic acid in jasmonate-regulated stress responses is reviewed.
Article
People's diet offers a greater and more diverse group of plant bioactives than do drugs, and they often do not realise that many drugs are derived from the compounds originally discovered in plant foods. Numerous epidemiological studies indicate that Brassica vegetables in general, and broccoli in particular, protect humans against cancer since they are rich sources of glucosinolates as well as possessing a high content of flavonoids, vitamins and mineral nutrients. One unusual phytotherapeutic role of broccoli is for skin diseases--the juice of the leaves is used to treat warts. However, the main use of broccoli stems from its health-promoting properties. Some criteria have been proposed to evaluate the possibilities of developing new "functional foods" to reduce the risk of specific cancers; largely in broccoli, which is associated with cancer protection. Processing conditions, transport, domestic cooking, etc., affect the health-promoting properties of broccoli and these have been widely studied. This review makes an in-depth study of the chemical and biological characterization of the phytochemicals of broccoli and the effects on the bioactive composition of broccoli.
Article
Changes in phenolic compounds, total glucosinolates, and vitamin C were monitored during the productive period along five inflorescence development stages of three broccoli commercial cultivars (Marathon, Monterrey, and Vencedor). In an attempt to identify differences due to agronomic factors, broccoli cultivars were grown under different sulfur fertilization with poor (15 kg/ha) and rich (150 kg/ha) rates. Phenolic compounds and vitamin C concentrations showed, in all broccoli cultivars, a rising trend from the first stage until the over-maturity stage, both for rich and poor sulfur fertilization. Significant differences were detected in the first two stages between rich and poor sulfur fertilization in total glucosinolates for all broccoli cultivars, where the highest concentration was always observed in the second development stage (used as minimally processed product) during poor fertilization. With regard to the last three stages, the glucosinolate concentration in the poor sulfur fertilization started to slope down until the over-maturity stage. Where rich sulfur fertilization is concerned, the highest level was reached during the third stage (used as minimally processed product also), and after that, glucosinolate concentration decreased until the fifth stage.