Article

Health-Promoting Compounds in Broccoli as Influenced by Refrigerated Transport and Retail Sale Period

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

Total aliphatic and indole glucosinolates, phenolic compounds (flavonoids and hydroxycinnamoyl derivatives), and vitamin C contents were evaluated in freshly harvested broccoli (Brassica oleracea L., var. italica, cv. Marathon) inflorescences. These were film-wrapped and stored for 7 days at 1 degrees C to simulate a maximum period of commercial transport and distribution. After cold storage, inflorescences were kept for 3 days at 15 degrees C to simulate a retail sale period. For wrapping, low-density polyethylene (LDPE) of 11 microm thickness was used. Gas composition was about 17% O(2) and 2% CO(2) during cold storage and about 16% O(2) and 3-4% CO(2) during shelf life within packages. The predominant glucosinolates were 4-methylsulfinylbutyl-glucosinolate (glucoraphanin), 3-indolylmethyl-glucosinolate (glucobrassicin), and 1-methoxy-3-indolylmethyl-glucosinolate (neoglucobrassicin). The predominant hydroxycinnamoyl derivatives were identified as 1,2,2'-trisinapoylgentiobiose, 1,2-diferuloylgentiobiose, 1,2'-disinapoyl-2-feruloylgentiobiose, and 3-O-caffeoyl-quinic (neochlorogenic acid). Results showed major losses at the end of both periods, in comparison with broccoli at harvest. Thus, the respective losses, at the end of cold storage and retail periods, were 71-80% of total glucosinolates, 62-59% of total flavonoids, 51-44% of sinapic acid derivatives, and 73-74% caffeoyl-quinic acid derivatives. Slight differences in all compound concentrations between storage and retail sale periods were detected. Distribution and retail periods had minimal effects on vitamin C. Weight loss was monitored at the end of both periods.

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... In Brassica, phenolic compounds are widely considered to be the most important specialized metabolites with antioxidant activity, responsible for the beneficial effects on human health [6]. Hydroxycinnamic acids, such as caffeic, ferulic, sinapic, and p-coumaric acid, are among the most widespread phenolics in these plants, in which they are differently conjugated to organic acids, such as quinic and malic acid, and sugars, such as sophorose and gentiobiose [7][8][9]. Extensive studies on different varieties of Brassica species have disclosed variations in their composition [10][11][12]. Moreover, Brassica species are also rich in flavonols, with kaempferol, quercetin, and isorhamnetin as the main aglycones. ...
... It is interesting to note that the wild Brassica species investigated here are characterized by a higher content of flavonol derivatives with respect to gentiobiosides, as shown in Table 2. It has been reported that in other Brassica species like broccoli, gentiobiosides were the most representative phenolic compounds [7,10]. ...
... for details. Figure S5: Characteristics of the four Brassica wild species evaluated in the present work. Whole plant (left) and leaves (right) of B. incana (1-2), B. macrocarpa (3-4), B. rupestris (5-6), and B. villosa (7)(8). ...
Article
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In the present study, we evaluated for the first time the variability of antioxidant traits of four Brassica wild species: B. incana, B. macrocarpa, B. villosa, and B. rupestris. The content of the main water-soluble antioxidants (phenolics, ascorbic acid, and total biothiols) and the in vitro antioxidant potential (1,1-diphenyl-2-picrylhydrazil (DPPH) and superoxide anion scavenging capacity) were investigated. A total of 28 polyphenolic compounds were identified by LC/MS and quantitated by HPLC/DAD analysis. Kaempferol and quercetin derivatives were the most abundant phenolics compared to hydroxycinnamoyl gentiobiosides. In the ten populations, phenolics ranged from 163.9 to 533.9 mg/100 g dry weight (d.w.), ascorbic acid from 7.6 to 375.8 mg/100 g d.w., and total biothiols from 0.59 to 5.13 mg/100 g d.w. The different classes of phytochemicals were separated using solid-phase extraction at increasing methanol concentrations, and the antioxidant power of fractionated extracts was evaluated. The superoxide anion scavenging activity was significantly correlated to phenolics, particularly to flavonol derivatives, while DPPH was mainly related to ascorbic acid content. The present findings improve the knowledge of the phytochemical composition of Italian Brassica wild species by showing the great diversity of phytochemicals among populations and highlighting their importance as a valuable genetic resource for developing new cultivars with improved bioactive content.
... Broccoli (Brassica oleracea L. var. Italica) is recognized as a functional food due to its high content of health-promoting compounds such as ascorbic acid, phenolic compounds, glucosinolates and isothiocyanates [1,2]. ...
... Chromatographic data of analyses was processed with OpenLAB CDS ChemStation software (Agilent Technologies, Santa Clara, CA, USA). Individual desulfoglucosinolates were identified based on retention time and UV spectra, as compared with authentic standards and previous reports [1,12,18,26]. A standard curve of desulfoglucoraphanin was prepared in the range of 0-700 µM for the quantification of glucosinolates. ...
... Phenolic compounds were detected at 320 nm. Identification of individual phenolics was performed based on retention time and UV spectra, as compared with authentic standards and previous reports [1,12,18]. A standard curve of 5-O-CQA was prepared in the range of 0-250 ppm for the quantification of phenolic compounds. ...
Article
Postharvest treatments such as wounding, ultrasound (US) and the exogenous application of ethylene (ET) and methyl jasmonate (MJ) have been studied as an effective tool to improve the content of secondary metabolites in fresh produce. The present study evaluated the immediate and late response (storage for 72 h at 15 °C) to US treatment (20 min, frequency 24 kHz, amplitude 100 μm) alone and combined with exogenous MJ (250 ppm) and/or ET (1000 ppm) on glucosinolates, isothiocyanates, phenolic compounds and ascorbic acid content in broccoli florets. US treatment increased the extractability of glucosinolates [glucoraphanin (795%), 4-hydroxy glucobrassicin (153%), glucobrassicin (78.6%)] and phenolics [1-sinapoyl-2-feruloylgentiobiose (57.23%)] as compared with the control (CT). The combined application of MJ and US in broccoli florets, induced a synergistic effect on the accumulation of 4-hydroxy glucobrassicin (187.1%), glucoerucin (111.92%), gluconasturtiin (755.9%), neoglucobrassicin (232.8%), 3-O-caffeoylquinic acid (73.4%), 1-sinapoyl-2-ferulolylgentiobiose (56.0%), and 1,2,2-trisinapoylgentiobiose (136.7%) at 72 h of storage. Interestingly, when the three stressors were applied together the synergistic effect of US + MJ observed on the accumulation of glucosinolates and phenolics was repressed. In general, the ascorbic acid content was not affected by US treatment and decreased in most samples during storage. However, when MJ + ET were applied, the content of total ascorbic acid was significantly reduced in CT + MJ + ET and US + MJ + ET samples after 72 h of storage by 53.4% and 86.6%, respectively, as compared with CT 0 h samples. Based on the results herein obtained, the application of US can be an effective tool to enhance the extractability of certain glucocosinolate and phenolic compounds in broccoli. Moreover, due to the synergistic effect observed on the accumulation of bioactive compounds, the combined application of US and MJ could be a practical approach to yield higher levels of glucosinolates and phenolic compounds in broccoli during storage.
... When vegetables are cooked, glucosinolates can be reduced by 30-60% via thermal degradation but primarily due to leaching into the cooking water when boiled [71][72][73]. Thawing of frozen cruciferous vegetables, without previous inactivation of myrosinase, leads to almost complete loss of glucosinolate as the cell structure is broken and water becomes available for reactions to occur [74]. Commercial transport, distribution and storage during the retail sale period also lead to significant losses, with a 40% loss of aliphatic glucosinolates after 7 days of storage and a 66% loss after 10 days [74]. ...
... Thawing of frozen cruciferous vegetables, without previous inactivation of myrosinase, leads to almost complete loss of glucosinolate as the cell structure is broken and water becomes available for reactions to occur [74]. Commercial transport, distribution and storage during the retail sale period also lead to significant losses, with a 40% loss of aliphatic glucosinolates after 7 days of storage and a 66% loss after 10 days [74]. To minimize these losses, rapid cooking at sub-boiling This article is protected by copyright. ...
... sautéing, steaming, or stir-fryingthermally inactivates myrosinase without leaching and thereby stabilizes glucosinolate levels. Greater isothiocyanate yields at consumption can be realized by pre-treating vegetables at 60 °C to selectively inactivate epithiospecifier protein (ESP) such that a greater proportion of intermediates rearrange to isothiocyanates upon processing or chewing [74][75][76]. It has also been shown that isothiocyanates in broccoli juice are relatively thermolabile and pressure stable [77]. ...
Article
Bladder cancer is a significant health burden due to its high prevalence, risk of mortality, morbidity, and high cost of medical care. Epidemiologic evidence suggests that diets rich in cruciferous vegetables, particularly broccoli, are associated with lower bladder cancer risk. Phytochemicals in cruciferous vegetables, such as glucosinolates, which are enzymatically hydrolyzed to bioactive isothiocyanates, are possible mediators of an anticancer effect. In vitro studies have shown inhibition of bladder cancer cell lines, cell cycle arrest and induction of apoptosis by these isothiocyanates, in particular sulforaphane and erucin. Although, not yet completely understood, many mechanisms of anti‐cancer activity at the steps of cancer initiation, promotion and progression have been attributed to these isothiocyanates. They target multiple pathways including the adaptive stress response, phase I/II enzyme modulation, pro‐growth, ‐survival, ‐inflammatory signaling, angiogenesis, and even epigenetic modulation. Multiple in vivo studies have shown the bioavailability of isothiocyanates and their anti‐tumoral effects. Although human studies are limited, they support oral bioavailability with reasonable plasma and urine concentrations achieved. Overall, both cell and animal studies support a potential role for isothiocyanates in bladder cancer prevention and treatment. Future studies are necessary to examine clinically relevant outcomes and define guidelines on ameliorating the bladder cancer burden. This article is protected by copyright. All rights reserved
... Individual GSL were prepared using a standard curve of desulfoglucoraphanin ranging from 0 to 1250 ppm. The concentrations of total and individual GSL were expressed as mg of desulfoglucoraphanin equivalents per g of broccoli sprouts dry weight (DW), while individual GSL were identified based on retention time as compared with authentic standards and previous reports [22,[25][26][27]. ...
... Finally, the target glucosinolate to obtain a high concentration in the extract was glucoraphanin, considered the most relevant aliphatic glucosinolate as it is the sulforaphane precursor of a highly antioxidant isothiocyanate [27]. The selected treatments for scalability tests were the treatments that showed the highest concentrations of glucoraphanin: 50% etOH, 65 • C, 1:25 (w/v) or 50% etOH, 40 • C, 1:35 (w/v). ...
Article
Full-text available
Glucosinolates and their enzyme-degraded metabolites, such as isothiocyanates, have shown great potential to prevent and treat chronic-degenerative diseases. Broccoli sprouts (Brassica oleracea L., var. italica) are an excellent source of glucosinolates. The objective of this study was to evaluate different process conditions (temperature, solvent concentration, and sample:solvent ratio) for the extraction of glucosinolates present in broccoli sprouts. The study evaluated different combinations of temperature (15–64 ◦C), ethanol concentration (0–100%), and sample:solvent ratio (1:15–1:35 w/v). The treatment with 40 ◦C, 50% ethanol/water (v/v), 1:35 (w/v) generated the highest extraction of total glucosinolates (100,094 ± 9016 mg/kg DW). The ethanol percentage was the factor that exerted the greatest impact on glucosinolate extraction (p < 0.05). In addition, the amount of glucoraphanin in the extract was determined, obtaining a final concentration of 14,986 ± 1862 mg/kg DW of sprouts processed under the optimal extraction conditions studied. The data presented herein demonstrate the relevance of the ethanol concentration during the extraction and the importance of applying high temperature in solid-liquid phase extraction. Under optimal conditions, it was possible to obtain extracts rich in glucosinolates to prepare food supplements, nutraceuticals, and even pharmaceuticals with application in the prevention and treatment of chronic-degenerative diseases.
... This behavior can be attributed to the fact that the leaves packed in polyethylene packaging have presented a fresh weight loss twice higher than the leaves packed in polyamide packaging ( Figure 5), which promoted the highest concentration of compounds in the first one. Vallejo et al. (2003) [47] studied the freshly harvested broccoli stored for 7 days at 1°C to simulate the maximum time spent on transportation and distribution of the product and for another 3 days at 15°C, in order to simulate the time spent in the food market. Furthermore, the authors found that after 10 days, a considerable loss in total phenolic contents occurred, around 44-51, 59-62 and 73-74% on a wet basis for synaptic acid derivatives, total flavonoids and derivatives of caffeoylquinic acid. ...
... This behavior can be attributed to the fact that the leaves packed in polyethylene packaging have presented a fresh weight loss twice higher than the leaves packed in polyamide packaging ( Figure 5), which promoted the highest concentration of compounds in the first one. Vallejo et al. (2003) [47] studied the freshly harvested broccoli stored for 7 days at 1°C to simulate the maximum time spent on transportation and distribution of the product and for another 3 days at 15°C, in order to simulate the time spent in the food market. Furthermore, the authors found that after 10 days, a considerable loss in total phenolic contents occurred, around 44-51, 59-62 and 73-74% on a wet basis for synaptic acid derivatives, total flavonoids and derivatives of caffeoylquinic acid. ...
Article
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The study presents itself as an alternative for the minimal processing of crushed cassava leaves, a product widely used in the Northern Brazilian cuisine. A Box-Behnken design was used to define the concentration of the sodium hypochlorite solution (NaClO) and the immersion time (t) capable of guaranteeing acceptable levels for thermotolerant coliforms and molds and yeasts in the leaves. The leaves sanitized in this condition were crushed, packed in polyethylene packaging under standard atmosphere (PE-WV) and under vacuum (PE-V); also packed in polyamide packaging under vacuum (PA-V), and stored at 7ºC for 30 days. The following properties were monitored: fresh weight loss, water activity, pH, titratable acidity, soluble solids, instrumental color, chlorophyll a and b, and total phenolic contents. In addition, there were assessed Salmonella spp, coliform at 45ºC, molds and yeasts and psychrotrophic bacteria. The 20 min immersion time and 250 mg/L NaClO solution were defined as the optimal conditions for the sanitization of the leaves and, after that, the leaves were rinsed with water. The behavior of the physical-chemical and microbiological properties indicated that the sanitized and crushed cassava leaves will be suitable for consumption for 24 h when packed in PE-WV; for 7 days when packed in PE-V and for 14 days when packed in PA-V, at 7°C storage.
... The same authors confirm that the main antioxidant content is observed in sprouts that grow with a strong temperature range of 30/15 °C day/night. Autumn/winter season crops, grown at lower temperature, lower light intensity, shorter days, and higher water availability, tend to have the lowest total GLS and other phytochemicals concentration [119,120]. An exception is represented by a turnip that produces higher flavonoids and vitamin C content in the autumn/winter season; this crop accumulates and produces the main phytochemicals with low/moderate temperature and considerable radiation, mainly in turnip tops [121]. ...
... There is a correlation between the increase in sulphur supply and higher levels of total GLS [138], in turnip [136], kale [137] and broccoli, mainly when associated with a reduction in water, at the expense of yield [139]. Vallejo and co-authors [119] suggested that the effect of sulphur application on GLS varies with the development stage of broccoli plants and differs for each kind of GLS; in fact, they found an increase in total GLS content at the start of the inflorescence development, followed by a rapid decrease thereafter. Increasing sulphur fertilization brought about a positive impact in the synthesis of polyphenols, such as flavonols and phenolic acids, increasing the total antioxidant capacity in turnip top (B. ...
Article
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Recently, the consumption of healthy foods has been related to the prevention of cardiovascular, degenerative diseases and different forms of cancers, underlying the importance of the diet for the consumer’s health. Fruits and vegetables contain phytochemicals that act as protective factors for the human body, through different mechanisms of action. Among vegetables, Brassica received a lot of attention in the last years for the phytochemical compounds content and antioxidant capacity that confer nutraceutical value to the product. The amount of healthy bioactive compounds present in the Brassica defines the nutritional quality. These molecules could belong to the class of antioxidant compounds (e.g., phenols, vitamin C, etc.), or to non-antioxidant compounds (e.g., minerals, glucosinolates, etc.). The amount of these compounds in Brassica vegetables could be influenced by several factors, depending on the genotypes, the environmental conditions and the cultivation techniques adopted. The aim of this study is to highlight the main phytochemical compounds present in brassicas used as a food vegetable that confer nutritional and sensorial quality to the final product, and to investigate the main factors that affect the phytochemical concentration and the overall quality of Brassica vegetables.
... Broccoli is a valuable vegetable crop for human health due to its nutritional value. Broccoli is an important source of ascorbic acid, folates, glucosinolates, flavonoids, vitamins and dietary fibers (Vallejo et al., 2003). Broccoli intake may reduce some types of cancer (Moreno et al., 2006). ...
... The reduction in some constituents, e.g. phenolic compounds was attributed to their bioconversion to antioxidants involved in cell protection (Vallejo et al., 2003). ...
Article
The present study was conducted to assess the effect of certain biomodulators (BMs) on growth, yield, and storability as well as on bioactive constituents either before or after storage of deficit-irrigated broccoli. The tested BMs were yeast extract (YE), moringa leaves extract (MLE), salicylic acid (SA) and humic acid (HA). Deficit irrigation (DI) was achieved by extending the duration between subsequent irrigations from five days (control) to either ten (IR10) or 15 days (IR15). Results indicated that all applied BMs alleviated DI effects on growth and yield. Post-harvest decline in quality was delayed by DI as biomass loss percentage (BLP %) and post-harvest decay percentage (PHD %) were decreased. All applied BMs also preserved inflorescence quality during storage as BL% and PHD% were lower in BMs-treated plants compared with control. Chlorophylls, carotenoids, ascorbic acid, total phenols and total soluble carbohydrates in broccoli inflorescence were decreased in IR10 and IR15 plants whereas increased in BMs-treated plants. Anthocyanins content was not significantly affected in response to DI treatments and peroxidase activity was not significantly affected in response to either DI or BMs treatments. It was concluded that treatments with BMs could be a feasible approach to avoid yield losses in water-stressed broccoli and that treatments with BMs of deficit-irrigated plants maintain post-harvest quality of broccoli heads during storage.
... Total phenol content was significantly higher in conventional oranges compared to its organic production, but total phenol content was significantly higher in organic strawberries than the conventional ones. High temperature environment can cause changes in flavonoids and polyphenols, resulting in the subsequent change in their antioxidant capacity as well (Vallejo et al., 2003). Key factors affecting the antioxidants content in organic plants are shown in Fig. 1. ...
... Key factors affect the antioxidant content in organic plants. Adapted fromVallejo et al., 2003. ...
Chapter
The production of organic foods, one of the most important branches of ecological agriculture, has developed rapidly all over the world. In addition to paying attention to sustainable organicproductionmodesandprotectionoftheenvironment,peoplehaveastronginterestin the quality of organic food. Focusing on the nutrition and safety differences of organic and conventional food, a wide range of research in the world has compared conventional and organic agricultural systems. The field of food quality has drawn much attention regarding differences between conventional and organic foods. This chapter aims at assessing past research that focuses on the comparison of the nutrients and contaminants present between organically and conventionally produced agricultural foods.
... Total phenol content was significantly higher in conventional oranges compared to its organic production, but total phenol content was significantly higher in organic strawberries than the conventional ones. High temperature environment can cause changes in flavonoids and polyphenols, resulting in the subsequent change in their antioxidant capacity as well (Vallejo et al., 2003). Key factors affecting the antioxidants content in organic plants are shown in Fig. 1. ...
... Key factors affect the antioxidant content in organic plants. Adapted fromVallejo et al., 2003. ...
... post-harvest storage strategies across a large range of broccoli cultivars [4,[9][10][11]. However, there is limited data on the changes in consumer perception driven by changing biochemical profiles of broccoli during storage. ...
... Commercially, broccoli is chilled to 0 • C within five hours and packed on ice for transport [3]. The broccoli arrives at the store within 7 to 14 days of harvest and is placed in a refrigerated grocery aisle until purchased or considered waste (typically around one week) [3,4]. As harvested broccoli ages, it senesces with time causing the nutritional and sensory profiles to change. ...
Article
Full-text available
Typically, broccoli arrives at the store within 7–14 days of harvest and is kept refrigerated until purchased or considered waste. To date, information has been limited on how this time on the shelf or storage temperature affects the sensory attributes that contribute to broccoli purchase or repurchase. In this study, 100 consumers performed acceptance tests and a check-all-that-apply (CATA) section to characterize sensory changes in two cultivars of broccoli (‘Diplomat’ and ‘Emerald Crown’) stored at two temperatures (0 °C and 4 °C) over five time points: 0, 14, 21, 28, and 42 days. Due to quality degradation during storage, the overall liking of broccoli decreased regardless of holding temperature and variety. This was in accordance with a decrease in sweetness and an increase in bitterness intensity. However, there were differences between varieties in which Diplomat had more sensory changes at higher temperatures and only Emerald showed negative changes to its appearance in color. Lastly, the CATA data revealed the attributes responsible for modulating the consumer acceptance of broccoli such as tastes, colors and flavors (e.g., grassy, musty, dirt-like). This information can be used to better inform shelf-life determinations of broccoli. Additionally, these changes in taste, odor, texture, and color can inform those interested in investigating the biochemical processes related to broccoli storage.
... AA is a highly nutritional compound in broccoli, due to its antioxidant content and free radical scavenging activities, which plays an important role in the human diet [31]. However, AA can decrease under less-than-ideal handling and storage conditions [32]. ...
Article
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Broccoli is a highly perishable crop, due to its high respiration rate, and rapidly loses quality under inappropriate handling temperatures. The objective of this study was to evaluate the effect of commercial hydrocooling (HY), forced-air cooling (FA) or slushed-ice cooling (SI) on the quality and shelf-life of two commercial broccoli cultivars (‘Marathon’ and ‘Eastern Crown’) grown in northeast Florida during the early spring season. Following HY and FA, individual bunches (‘Marathon’) or crowns (‘Eastern Crown’) were placed in plastic film bags and stored at 1 °C for 7 days then transferred to 5 °C for 8 days to simulate retail conditions. It was found that HY removed the field heat 3.6 and 4.8 times faster than FA and SI, respectively. For both cultivars, using a texture analyzer, broccoli cooled by SI were softer (20.4 to 27.9 N) with higher head deformation than those by HY or FA (45.6 to 58.9 N) after 15 days of storage. Overall appearance of both cultivars decreased during storage if infected in the field by the fungal pathogen Alternaria brassicicola, which causes black spot disease. However, by the end of storage ‘Eastern Crown’ had a higher quality rating (6.2) than ‘Marathon’ (5.4). Broccoli floret moisture content was not affected during storage; however, ‘Marathon’ had higher moisture content (94.7%) than ‘Eastern Crown’ (89.2%). Yellowing was expressed more for ‘Marathon’, which had higher chroma* value (21.4) and lower hue* angle (h*) (122.3) value than ‘Eastern Crown’ after 7 days at 1 °C, plus 8 days at 5 °C. Carotenoid content was similar for both cultivars at harvest (2.3 mg/100 g) then decreased 39% for ‘Marathon’ and 12% for ‘Eastern Crown’ by day 15. Total chlorophyll was similar for both cultivars throughout storage (22.6 mg/100 g). Ascorbic acid decreased for both cultivars during storage but was higher in ‘Eastern Crown’ (92.0 to 101.9 mg/100 g) compared to ‘Marathon’ (80.7 to 88.6 mg/100 g). Hydrocooling and forced-air plus overwrapping have potential to reduce cooling costs during commercial handling.
... Even under cold storage conditions, significant declines in phytochemicals content have been observed in broccoli florets after harvest [51]. SA is capable of maintaining bioactive components with antioxidant effects in horticultural commodities [52]. ...
Article
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Abstract: The importance of broccoli (Brassica oleracea var. italica) consumption has increased in recent years due to its significant amount of anticarcinogenic and antioxidant compounds, as well as its many vitamins. However, broccoli florets are a highly perishable product which rapidly senesce and turn yellow after harvest, resulting in losses in nutritional and bioactive compounds. Thus, in this study, we evaluated the effect of postharvest exogenous of salicylic acid (SA) and calcium chloride (CaCl2) and their combination on the quality of broccoli florets stored at 5 �C for 28 days to minimize the rapid senescence of broccoli florets. Samples treated with 2 mM SA alone or in combination with 2% CaCl2 showed lower weight loss and lower losses of chlorophyll content, vitamin C, phenolic compounds, carotenoids, flavonoids, and glucosinolates compared with the control samples. Additionally, antioxidant activity was maintained by either SA or SA + CaCl2 treatments while peroxidase activity was decreased. For higher quality and lower losses in antioxidant compounds of broccoli florets during refrigerated storage at 5 �C, SA + CaCl2 treatment could be helpful for up to 21 days.
... The mechanisms whereby vegetables could impact on acute postprandial GR might be explained as follows: (1) the polyphenols and phenolic acids [60] could inhibit digestive enzymes [61], such as pancreatic α-amylase [62], the Na + -glucose co-transporter [63], and thus modulate carbohydrate metabolism [64]; (2) the fibers could increase viscosity, delay gastric emptying, reduce the accessibility to enzymes, and inhibit amylase activity [65]; ...
Article
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This study aimed to investigate the effect of the oral processing of vegetables induced by texture modification on acute postprandial glycemic response (GR) and insulin response (IR) when co-ingested and ingested prior to a rice meal. In a randomized crossover trial, 14 healthy female subjects consumed (1) co-ingestion of soft broccoli and rice (SR); (2) co-ingestion of hard broccoli and rice (HR); (3) soft broccoli prior to rice (S+R); (4) hard broccoli prior to rice (H+R); (5) rice (R). Postprandial GR and IR was compared between test meals over a period of 180-min, and the oral processing behaviors were measured for each test food samples. Hard broccoli was observed to have a higher mastication time and chews than soft broccoli. All the broccoli meals resulted in reduced incremental peak glucose (IPG) and an increased incremental area under the insulin curve in 180 min (iAUC0-180) compared with R. The S+R curbed the IPG by 40% with comparable HOMA-IR AUC0-180 compared with R, while the H+R elevated the HOMA-IR AUC0-180 by 62% more than that of R. In conclusion, the soft broccoli intake prior to a rice meal effectively attenuated postprandial GR, without lowering insulin sensitivity as its hard counterpart did.
... It shows the importance of analyzing the effect of food cooking on the content of phenolic compounds. Vallejo, Tomás-Barberán & Garcia-Viguera (2003) and Zambrano-Moreno et al. (2015) agrees with the fact that polyphenols content can increase and shows certain stability (remains constant) when they are exposed to high temperatures, a quality that is reflected in the preservation of their antioxidant capacity when compared to the fresh vegetable. On the other hand, Achckar et al. (2013) reported that thermal decomposition is one of the main causes of reduction in the content of these compounds, in which a reaction of the phenols can occur with other compounds in warm environments, blocking their extraction. ...
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Despite the high consumption of Japanese gherkin in the Northeast of Brazil, very few studies with this vegetable are found in the literature. As it is consumed raw or after cooking, being mainly consumed cooked, there was the interest to know if cooking could influence bioactive compounds content and antioxidant activity since high temperatures are related to benefits losses in food. This research aimed to compare the content of bioactive compounds and the antioxidant activity between in natura and cooked Japanese gherkin. Gherkins were submitted to quantification of carotenoids, anthocyanins, vitamin C and phenolic compounds, in addition to the antioxidant activity analyses through the ferric reducing antioxidant power (FRAP) and the DPPH free radical scavenging methods. After cooking, carotenoids (from 4.90 to 4.59 ?g.g-1) and phenolic compounds (from 17.07 to 14.95 mg.100 g-1) content decreased, but with no significant difference between in natura and cooked samples. As for the antioxidant activity, the in natura gherkin showed a higher value (3.31 ?M Ferrous Sulfate.g-1) than the cooked one (1.96 ?M Ferrous Sulfate.g-1) for FRAP method, while for DPPH method no difference between the samples was detected. Anthocyanin and vitamin C were not detected in gherkins. We concluded that, in general, cooking did not affect the bioactive compounds of gherkins and that antioxidant activity increased.
... In addition, PRO was not detected in this study, which is different from previous results. Because the GNA hydrolysate 3-butenyl ITC can induce the death of prostate cancer cells through apoptosis, and GRA and its derived isothiocyanate sulforaphane have anti-inflammatory, anticancer and neuroprotective effects [48][49][50][51][52], the Chinese kale varieties with high GRA and GNA content, such as ZH and QB1 involved in this study, have important nutritional and health functions. Obtaining varieties with high content of GRA and GNA is also the goal of breeding Chinese kale in the future. ...
Article
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The content and component of glucosinolates in edible stems and leaves of eight Chinese kale varieties from Japan and eight varieties from China were determined by HPLC-MS. Simultaneously, the expression levels of glucosinolate biosynthesis pathway genes from four varieties with high and low total glucosinolate contents were analyzed by the qRT-PCR method. Four types of aliphatic glucosinolates (A-GLSs: GRA, SIN, GNA and GER) and indole glucosinolates (I-GLSs: 4-HGBS, GBS, 4-MGBS and NGBS) were detected in the stems and leaves of 16 varieties, and no aromatic glucosinolates (R-GLSs) were detected. A-GLSs account for more than 80.69% of the total content of total glucosinolates (T-GLSs), in which GNA and GRA are the main components of stems and leaves. Among Japanese varieties, QB1 has higher content of A- and T-GLSs, while that of XLB was lower; however, the corresponding varieties were ZH and DSHH in Chinese varieties. Among the above four varieties, the expression levels of SOT16, CYP83B1, SOT17, CYP83A1 and MAM1 genes were significantly higher in the varieties with higher GLSs; the expression levels of SOT16 and CYP83B1 were consistent with the content of I-GLSs; and SOT17, CYP83A1 and MAM1 expression levels were consistent with A-GLSs content. At the same time, the expression levels of SOT16 and CYP83B1 in the leaves were higher than those in the stems. CYP83A1 and MAM1 genes were less expressed in the leaves than in the stems of lower content varieties. It is speculated that these genes may be the key genes regulating GLS biosynthesis in Chinese kale.
... In addition, Abbaoui et al also note how cruciferous vegetables are consumed can significantly change the amount of isothiocyonates and other bioactives an individual is exposed to [9]. For example, quantities of isothiocyanates in vegetables are significantly reduced by cooking and storage processes [29][30][31]. Therefore, the amount of isothiocyanates an individual consumes through cruciferous vegetables may not be enough to ever reach therapeutic levels to protect against bladder cancer. ...
Article
Background: Abundant pre-clinical data suggest that consumption of cruciferous vegetables might protect against bladder cancer. While small-scale clinical evidence supports this hypothesis, population-level data is lacking. We tested the hypothesis that consumption of cruciferous vegetables is associated with a lower risk of bladder cancer in a large population-based study. Methods: We investigated the association between dietary consumption of cruciferous vegetables and the risk of bladder cancer in the NIH-American Association of Retired Persons (AARP) Diet and Health Study. Diet at baseline was collected with self-administered food-frequency questionnaires. Bladder cancer diagnoses were identified through linkage with state cancer registries. Hazard ratio (HR) and 95% confidence intervals (CI) were estimated with Cox proportional hazards models. Results: Our analysis included 515,628 individuals. Higher intake of cruciferous vegetables, both overall and when stratified by variety (broccoli vs. brussels sprouts vs. cauliflower), were not associated with bladder cancer risk for men or women. A history of smoking did not affect the results. Conclusions: Our study shows no association between dietary consumption of cruciferous vegetables and incident bladder cancer.
... The results showed the effect of 1-MCP treatment in significantly better retention of ascorbic acid compared to the control during postharvest storage. The decrease in the contents of ascorbic acid in 'MKS-B107' broccoli during postharvest storage was consistent with the results of 'Pushpa' broccoli, 'Lvxiong' broccoli and 'Marathon' broccoli reported by Nath et al. (2011), Yuan et al. (2010 and Vallejo et al. (2003), respectively. ...
Article
Broccoli (Brassica oleracea L., cv. MKS-B107) is a highly perishable vegetable and it has a relatively short shelf life. Storage conditions and postharvest treatments are the important factors to determine the postharvest quality and the shelf life of broccoli. This study indicated the effects of 1–methylcyclopropene (1-MCP) and temperature on the quality of broccoli during storage period. Broccoli was treated with air (as control) and 1.0 µL L-1 1-MCP for 15 h at 15oC, and then was stored at 10oC and 0oC for 25 days and 50 days, respectively. The results showed that 1-MCP treated broccoli was in good quality during 50 days of storage at 0oC and 20 days of storage at 10oC compared to the control broccoli. The present study indicated that 1-MCP treatments suppressed the respiration rate and ethylene production, reduced the chlorophylls and ascorbic acid degradation and inhibited the color changes of broccoli during storage. Broccoli treated with 1.0 µL L-1 1-MCP and stored at 0oC represented remarkably better quality compared to broccoli of the other treatments.
... Losses associated with the recovery from abiotic stress represent the mean percentage daily loss of flavonol glycosides ± standard error of various metabolites in Arabidopsis thaliana [52,57] and tomato [42], including multiple studies. Postharvest handling flavonol glycosides losses represent the mean percentage daily loss of flavonol glycosides ± standard error of various metabolites, or across various cultivars and/or experimental treatment conditions [65,67,163,164]. On-the-plant development losses represent the mean percentage daily loss of flavonol glycosides ± standard error of various metabolites, including multiple studies [165,168]. ...
Article
Plants are the sole source of flavonoids, a chemical category that includes flavonols. For the most part, flavonols occur as glycosides with numerous postulated biological roles in plants, including photoprotection, modulation of hormone translocation, and sequestration of reactive oxygen species. Flavonol glycosides are often considered as dead-end metabolites because related flavonoids (i.e., anthocyanins) occur in terminal tissues such as flowers and fruit, but recent evidence points to their turnover in planta, including developing photosynthetic tissues. Although microbial degradation pathways for flavonol glycosides of plant origin are well described, plant catabolic pathways are little studied by comparison. This review will address our current understanding of biochemical processes leading to the loss of flavonol glycosides in plants, with a specific emphasis on the evidence for flavonol-specific β-glucosidases. Complete elucidation of these catabolic pathways is dependent on the identification of regiospecific modifying steps, including enzymes associated with the hydrolysis of rhamnosylated flavonols, as well as flavonol peroxidation and their encoding genes. Herein, we highlight challenges for the identification of hypothetical plant α-rhamnosidases and peroxidases involved in flavonol glycoside degradation, and the potential biological role of this catabolism in mitigating oxidative stress in developing and postharvest plant tissues.
... The small variability in GLS levels is an unexpected observation, as the analyzed white and red cabbages differed in genotype, came from different regions, were cultivated on different soil types using different fertilizers and storage practices, and were also purchased from different food retailers that belonged to different food trading companies ( Table 2, Supplemental Table S1). Previous studies showed that GLS levels in Brassica oleracea vegetables are affected by cultivar (genotype) [14,25], nutrient supply [26,27], climatic conditions [17,20,28], as well as storage conditions [29,30]. As the variability of the GLSs was relatively low, it is suspected that genotypes were similar in their initial GLS concentrations and that also cultivation practices and storage conditions had no major effect on the GLS content of the cabbages, when they were finally sold in the supermarket. ...
Article
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Brassica vegetables contain glucosinolates, which are well-known for their potential to form health-promoting isothiocyanates. Among those crucifers, white and red cabbage are commonly consumed vegetables, exhibiting different glucosinolate and hydrolysis profiles thereof. Regarding the health beneficial effects from these vegetables, more information, especially concerning the seasonal variation of glucosinolate profiles and the formation of their bioactive hydrolysis products in commercial cabbages, is needed. In this study, glucosinolates and glucosinolate hydrolysis product profiles in red and white cabbages from three different food retailers were monitored over six different sampling dates across the selling season in autumn. For the first time, it was shown that, while glucosinolate profiles were similar in each cabbage variety, glucosinolate hydrolysis product profiles and hydrolysis behavior varied considerably over the season. The highest total isothiocyanate concentrations were observed in conventional red (1.66 μmol/g FW) and organic white (0.93 μmol/g FW) cabbages purchased at the first sampling date in September. Here, red cabbage was with up to 1.06 μmol/g FW of 4-(methylsulfinyl)butyl isothiocyanate (sulforaphane), an excellent source for this health-promoting isothiocyanate. Cabbages purchased 11 weeks later in autumn released lower levels of isothiocyanates, but mainly nitriles and epithionitriles. The results indicate that commercial cabbages purchased in early autumn could be healthier options than those purchased later in the year.
... With regards to extrinsic aspects, short time storage at low temperature also affects polyphenol content as exemplified by the broccoli loss of its caffeoyl-quinic and sinapic acid contents [53]. Food processing is yet another external factor when considering polyphenol bioavailability. ...
Article
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Lifestyle factors, especially diet and nutrition, are currently regarded as essential avenues to decrease modern-day cardiometabolic disorders (CMD), including obesity, metabolic syndrome, type 2 diabetes, and atherosclerosis. Many groups around the world attribute these trends, at least partially, to bioactive plant polyphenols given their anti-oxidant and anti-inflammatory actions. In fact, polyphenols can prevent or reverse the progression of disease processes through many distinct mechanisms. In particular, the crosstalk between polyphenols and gut microbiota, recently unveiled thanks to DNA-based tools and next generation sequencing, unravelled the central regulatory role of dietary polyphenols and their intestinal micro-ecology metabolites on the host energy metabolism and related illnesses. The objectives of this review are to: (1) provide an understanding of classification, structure, and bioavailability of dietary polyphenols; (2) underline their metabolism by gut microbiota; (3) highlight their prebiotic effects on microflora; (4) discuss the multifaceted roles of their metabolites in CMD while shedding light on the mechanisms of action; and (5) underscore their ability to initiate host epigenetic regulation. In sum, the review clearly documents whether dietary polyphenols and micro-ecology favorably interact to promote multiple physiological functions on human organism.
... The content of the ascorbic acid, phenolic compounds and glucosinolates were determined using an Agilent HPLC system (Agilent Technologies, Waldbronn, Germany) equipped with a binary pump (G1312A), autosampler (G1313A), photodiode array detector (G1312A) controlled by Agilent software (v. A.08.03), and degasser (G1322A) following the methodology and sample preparation described in Vallejo et al., 2003. The values provided are the average of three replicates. ...
Article
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The aim of this work was to determine the physicochemical and functional properties of a Brassica napobrassica leaves powder sieved at three particle sizes. Moreover, in order to understand the potential interactions between the Brassica napobrassica leaves powder and starch, the pasting properties were assessed and the effect of pH (4–9) and temperatures (70–90 °C) on the phenolic compounds and antiradical activities were also evaluated. Particle size had an effect on physicochemical and functional properties of the vegetable powder. Vegetable fractions affected the apparent viscosity of starch suspension along heating and cooling, with larger effect during heating. The effect of the processing conditions on the functional properties of starch suspensions was influenced by the powder particle sized and the type of starch used. Maize starch seemed to interact more with phenolic compounds than rice starch, which resulted in a protective effect against pH and temperature variations, leading to higher antiradical activities.
... Indeed, a five-fold higher ITC yield was found from broccoli sprouts than mature broccoli in our study. Refrigerated storage and transportation also led to a loss in glucosinolates (Vallejo, Tomás-Barberán, & García-Viguera, 2003). Compared to an over 420-fold difference in ITC yields across all types of vegetables and condiments, the level of intravariation is less with a maximum of 30-fold difference within each type of sample. ...
Article
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Cruciferous vegetables are primary sources of dietary isothiocyanates (ITCs), a group of phytochemicals showing promising cancer‐chemopreventive activities in multiple cancer models. However, no study has thoroughly examined how cooking affects the yields of ITCs from cruciferous vegetables. In this study, a high‐performance liquid chromatography (HPLC)‐based cyclocondensation assay was performed to examine the ITC yields from four major cruciferous vegetables (broccoli, cabbage, cauliflower, and kale) under six cooking conditions (stir‐frying, steaming, microwaving, boiling, stewing, and chip‐baking for kale only) and measured the level of ITCs under the raw condition for a comprehensive list of cruciferous vegetables and ITC‐containing condiments. A wide range of ITC yields was found across vegetables and condiments. Cooking significantly altered the ITC yields, showing an averagely four‐fold increase by lightly cooking (stir‐frying, steaming, and microwaving) and a 58% decrease by heavily cooking (boiling, stewing, and chip‐baking). These findings will provide the evidence‐based cooking guidance on cruciferous vegetable consumption and help better estimate dietary ITC exposure in epidemiologic studies. Cooking significantly altered the isothiocyanate yields, showing an averagely four‐fold increase by lightly cooking (stir‐frying, steaming, and microwaving) and a 58% decrease by heavily cooking (boiling, stewing, and chip‐baking).
... 57,60 However, the content of these compounds might drastically diminish during sprout germination, 17,30 and in comparison with the phenolic components, they are also to the largest extent affected by storage or processing conditions. 61 Thus, SADs of the broccoli sprouts might play an important role in supporting the activity of sulfur constituents. ...
Article
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.
... Moreover, previous research demonstrated that partial or total inactivation of myrosinase, breakdown of glucosinolates at high temperatures, loss of enzymatic cofactors, leaching of glucosinolates and their metabolites into the cooking medium or volatilization, and/or thermal degradation of the metabolites can occur during cooking, as simplified in Table 2 [86]. Further, it was observed that environmental, cultivar, and genetic factors as well as industrial processing, storage, and domestic cooking contribute to a change in GL concentrations [25,90]. Additionally, GL content can be affected by the preparation of brassica vegetables before cooking. ...
Article
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Cancer is the main cause of mortality and morbidity worldwide. Although a large variety of therapeutic approaches have been developed and translated into clinical protocols, the toxic side effects of cancer treatments negatively impact patients, allowing cancer to grow. Brassica metabolites are emerging as new weapons for anti-cancer therapeutics. The beneficial role of the consumption of brassica vegetables, the most-used vegetables in the Mediterranean diet, particularly broccoli, in the prevention of chronic diseases, including cardiovascular diseases, diabetes, and obesity, has been well-documented. In this review, we discuss the anti-tumor effects of the bioactive compounds from Brassica vegetables with regard to the compounds and types of cancer against which they show activity, providing current knowledge on the anti-cancer effects of Brassica metabolites against major types of tumors. In addition, we discuss the impacts of industrial and domestic processing on the compounds’ functional properties before their consumption as well as the main strategies used to increase the content of health-promoting metabolites in Brassica plants through biofortification. Finally, the impacts of microbiota on the compounds’ bioactivity are considered. This information will be helpful for the further development of efficacious anti-cancer drugs.
... Such vegetables have a high number of phenolic components and are appreciable sources of polyphenols, especially flavonoids [33]. Figure 1 shows a schematic representation of the chemical composition of broccoli extract including the antioxidant species (i.e., α-lipoic acid, sulforaphane and coenzyme Q10) [32,34]. These flavonoids and phenolic acids are present in leaves, flowering tissues and other parts of the broccoli plant. ...
Article
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With the aim to reduce the entire cost of lithium-ion batteries and to diminish the environmental impact, the extract of broccoli is used as a strong benign reducing agent for potassium permanganate to synthesize α-KyMnO2 cathode material with pure nanostructured phase. Material purity is confirmed by X-ray powder diffraction and thermogravimetric analyses. Images of transmission electron microscopy show samples with a spider-net shape consisting of very fine interconnected nanoneedles. The nanostructure is characterized by crystallite of 4.4 nm in diameter and large surface area of 160.7 m2 g-1. The material delivers an initial capacity of 211 mAh g-1 with high Coulombic efficiency of 99% and 82% capacity retention after 100 cycles. Thus, α-KyMnO2 synthesized via a green process exhibits very promising electrochemical performance in terms of initial capacity, cycling stability and rate capability.
... Glucoraphanin, an aliphatic glucosinolate, and hydroxy-cinnamates also increased, but modestly, in the untreated broccoli florets during storage, while the total indole-type glucosinolates decreased during storage ( Fig. 4 and Fig. 5). The loss of glucosinolates in broccoli could be severe, when they are stored at ambient temperatures, but they are better preserved at low temperatures (Rangkadilok et al., 2002;Rybarczyk-Plonska et al., 2016;Vallejo et al., 2003). Considering the changes in the levels of glucosinolates and hydroxy-cinnamates in the control samples, it was likely that that these samples had been subject to infection, although the occurrence was not apparent. ...
Article
The effect of pre-storage exposure to ultra-violet radiation (UV-C) on preservation of broccoli (Brassica oleraceae var. Italica) florets and glucosinolates, phenolic acids and their precursor amino acids as well the expression of genes related to the biosynthetic pathways of glucosinolates and phenolic compounds in broccoli stored at 4 °C and 90–95% HR was investigated. The UV-C dose of 1.2 kJ m⁻² was found to be hormetic in delaying the yellowing and in lowering the weight loss of broccoli florets during storage. The time-averages over the storage period of both ascorbic acid titer and ORAC (oxygen radical absorbance capacity) value of the tissue exposed to hormetic dose of 1.2 kJ m⁻² or a high dose of 3.0 kJ m⁻² were lower. The overexpression of genes (phenylalanine N-hydroxylase, tryptophan N-hydroxylase, dihomo-methionine N-hydroxylase and flavonoid monooxygenase) in UV-C exposed broccoli, hours after exposure (0 d), and that of chalcone synthase and coumarate ligase was observed on day 0, 2 and 4. The titers of glucosinolate-precursor amino acids, methionine, tryptophan and phenylalanine in tissue were dose-dependent, where the doses of 1.2 and 3.0 kJ m⁻² UV-C caused a decrease in their concentrations compared to the control. Hormetic dose of UV-C significantly increased the concentration of total glucobrassicins and 4-hydroxyglucobrassicin. In addition, UV-C treated florets with the dose of 1.2 or 3.0 kJ m⁻² contained a higher level of hydroxycinnamic acids in broccoli compared to the control during the storage. The results suggest that the application of hormetic dose of UV-C can be beneficial in maintaining not only the quality of broccoli florets, but also in enhancing the phyto-compounds during the low-temperature storage.
... Another experimental work includes a curious study in which the conditions to which broccoli is subjected after harvesting are simulated, that is, it is transported and distributed at 1°C for 7 days, and then it is exposed at 15°C for 3 days. After this period of 10 days, the amount of GSLs had decreased between 70% and 80%, compared to the freshly harvested broccoli (Vallejo, Tomas-Barberan, & Garcia-Viguera, 2003). A similar study, but to which they added as a variant, the use of radiation (12 h/day), resulted in the fact that the period in which the samples remained between 0 and 4°C did not alter the content of GSLs, but the biggest differences occurred during storage between 10 and 18°C. ...
Chapter
Glucosinolates are a large group of plant secondary metabolites with nutritional effects and biologically active compounds. Glucosinolates are mainly found in cruciferous plants such as Brassicaceae family, including common edible plants such as broccoli (Brassica oleracea var. italica), cabbage (B. oleracea var. capitata f. alba), cauliflower (B. oleracea var. botrytis), rapeseed (Brassica napus), mustard (Brassica nigra), and horseradish (Armoracia rusticana). If cruciferous plants are consumed without processing, myrosinase enzyme will hydrolyze the glucosinolates to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. On the other hand, when cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. This review paper summarizes the glucosinolate molecular breakdown, their genetic aspects from biosynthesis to precursors, their bioavailability (assimilation, absorption, and elimination of these molecules), their sensory properties, identified healthy and adverse effects, as well as the impact of processing on their bioavailability.
... Another experimental work includes a curious study in which the conditions to which broccoli is subjected after harvesting are simulated, that is, it is transported and distributed at 1 °C for 7 days, and then it is exposed at 15 °C for 3 days. After this period of 10 days, the amount of GSLs had decreased between 70% and 80%, compared to the freshly harvested broccoli (Vallejo, Tomas-Barberan, & Garcia-Viguera, 2003). A similar study, but to which they added as a variant, the use of radiation (12 h/day), resulted in the fact that the period in which the samples remained between 0 and 4 °C did not alter the content of GSLs, but the biggest differences occurred during storage between 10 and 18 °C. ...
... Modified-atmosphere packaging (MAP) and low-temperature storage are widely used. A major decrease in glucosinolates during MAP storage for one week at 1°C has been reported in broccoli (117). Storage of fresh-cut bell pepper cubes at 5°C under 50% or 80% O 2 plus 15% CO 2 for up to nine days can inhibit growth of microbes and maintain overall sensory quality (21). ...
Article
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Although flavor is an essential element for consumer acceptance of food, breeding programs have focused primarily on yield, leading to significant declines in flavor for many vegetables. The deterioration of flavor quality has concerned breeders; however, the complexity of this trait has hindered efforts to improve or even maintain it. Recently, the integration of flavor-associated metabolic profiling with other omics methodologies derived from big data has become a prominent trend in this research field. Here, we provide an overview of known metabolites contributing to flavor in the major vegetables as well as genetic analyses of the relevant metabolic pathways based on different approaches, especially multi-omics. We present examples demonstrating how omics analyses can help us to understand the accomplishments of historical flavor breeding practices and implement further improvements. The integration of genetics, cultivation, and postharvest practices with genome-scale data analyses will create enormous potential for further flavor quality improvements. Expected final online publication date for the Annual Review of Plant Biology Volume 70 is April 29, 2019. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
... Results revealed richness of B. oleracea species in phenolic compounds and alkaloïds which is in accordance with previous studies (Bahorun et al. 2004;Scalzo et al. 2008;Vallejo et al. 2003;Wu and Prior 2005). Results have also shown a variation in secondary metabolites amounts with cabbage varieties. ...
Article
Saad, I., Rinez, I., Ghezal, N., and Haouala, R. 2017. Chemical composition and herbicidal potent of cauliflower (Brassica oleracea var. botrytis) and cabbage turnip (Brassica oleracea var. gongylodes). Tunisian Journal of Plant Protection 12: 95-113. This study was conducted to evaluate the phytochemical content and allelopathic potential of two cabbages botanical varieties leaves, ie. cauliflower (Brassica oleracea var. botrytis) and cabbage turnip (B. oleracea var. gongylodes). Their aqueous and organic extracts were evaluated on lettuce (Lactuca sativa) and one of the most dominant weeds in Tunisia, nettle-leaf goosefoot (Chenopodium murale). Field experiments were conducted to evaluate the smothering potential of the two varieties. The total phenolics, flavonoïds, flavonols and flavones, alkaloïds, and proanthocyanidins contents were higher in the aqueous extracts of both varieties. For organic extracts, petroleum ether and methanol cauliflower extracts and chloroform and methanol cabbage turnip extracts were the richest ones. All aqueous and organic extracts had significantly delayed germination, reduced its rate and affected seedling growth. Reduction of germination and growth were more important using the higher concentrations and in presence of cabbage turnip extract. The organic extracts of both varieties had significantly inhibited the seedling growth of target species, especially petroleum ether, and methanol cauliflower extracts and chloroform and methanol cabbage turnip ones. Field experiment highlighted the smothering potential of the two varieties and confirmed the higher allelopathic potential of cabbage turnip as compared to cauliflower.
... Broccoli (Brassica oleracea L. Italaia) is a widely-consumed floral green vegetable which has high levels of vitamins, antioxidants, anticarcinogenic compounds (Nestle, 1998;Ares et al., 2014) and glucosinolates (Yuan et al., 2010) which have been associated with cancer protection and the reduction of cardiovascular diseases (Talalay et al., 1995;Kushad et al., 1999;Rangkadilok et al., 2002;Vallejo et al., 2003;Ku et al., 2013). Broccoli has also been ranked as one of the best inducers of detoxification enzymes in mammals (Dominguez-Perles et al., 2011). ...
... Os brócolis pertencem à espécie Brassica oleracea L. e se destacam pela presença de glucosinolatos, fl avonoides, vitaminas C, E e A e pela propriedade antioxidante (PAGE et al., 2001;LEMOINE et al., 2009; VALLEJO; GARCÍA-VIGUERA; TOMÁS- BARBERÁN, 2003). Há cultivares do tipo ramoso e do tipo cabeça, sendo que o tipo ramoso se caracteriza por apresentar grande número de infl orescências pequenas e com botões fl orais grandes. ...
... Broccoli (Brassica oleraceae var italica) being a gold mine of phytochemicals and natural antioxidants such as ascorbic acid, β-carotene, tocopherols, phenolics, flavonoids and glucosinolates, it helps in reducing the risk of cardio vascular diseases, diabetes and curing of cancers 31 . Consumption of 150 g of broccoli per day satisfies an adult's requirements for vitamins E, A, B 1 and C and boosts the immune system 4 . ...
Chapter
Glucosinolates are characteristic metabolites of Brassicaceae family which includes many edible species. Glucosinolate profile differs qualitatively as well as quantitatively among species, varieties, cultivars, and also within a plant. Glucosinolates (nitrogen and sulfur-containing compounds) are hydrolyzed by plant and/or gut myrosinase to different biologically active compounds including isothiocyanates, nitriles, and thiocyanates. These bioactive compounds, especially isothiocyanates, possess a variety of health-promoting properties like anticarcinogenic, antiinflammatory, antimicrobial, and antioxidant. There are few studies showing toxicity effects in livestock species like goiter, gastrointestinal irritation, and anemia. Bioavailability of isothiocyanate for health-promoting functions is greatly regulated by storage and culinary practices as well as the composition of gut microflora of the individual. This chapter summarizes hydrolysis, bioavailability, and mechanism of action of glucosinolates and their by-products.
Article
This study evaluated the effect of argon-enriched modified atmosphere on the storage extension of ready-to-use broccoli rabe in leaf. Broccoli rabe samples ( Brassica rapa sylvestris L. var. esculenta) were packaged in 90% argon and 10% O 2 (modified atmosphere packaging 1); 80% argon, 10% CO 2 and 10% O 2 (modified atmosphere packaging 2) and evaluated for the physicochemical characteristics, microbiological parameters and bioactive compounds (glucosinolates) during the cold storage for 9 days. Results showed significant maintenance of colour, chlorophyll, phenols content and antioxidant activity in modified atmosphere packaging packages with respect to air control ones. An increasing biosynthesis of glucosinolates was observed in all packages to the inductive effect of CO 2 produced; the amount of minerals unchanged during the storage. Overall appearance and odour evaluation pointed out a positive effect of argon atmospheres, in particular modified atmosphere packaging 1, for the keeping of the sensory attributes compared to those evaluated in air packaging.
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This book provides the first systematic and accessible text for students of hospitality and the culinary arts that directly addresses how more sustainable restaurants and commercial food services can be achieved. Food systems receive growing attention because they link various sustainability dimensions. Restaurants are at the heart of these developments, and their decisions to purchase regional foods, or to prepare menus that are healthier and less environmentally problematic, have great influence on food production processes. This book is systematically designed around understanding the inputs and outputs of the commercial kitchen as well as what happens in the restaurant from the perspective of operators, staff and the consumer. The book considers different management approaches and further looks at the role of restaurants, chefs and staff in the wider community and the positive contributions that commercial kitchens can make to promoting sustainable food ways. Case studies from all over the world illustrate the tools and techniques helping to meet environmental and economic bottom lines. This will be essential reading for all students of hospitality and the culinary arts. Available from: https://www.routledge.com/The-Sustainable-Chef-The-Environment-in-Culinary-Arts-Restaurants-and/Gossling-Hall/p/book/9781138733732
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When minimally processed vegetables reach their expiration date, expose an increased microbial load. This includes mainly spoilage microorganisms but also foodborne pathogens, thus affecting the quality and safety of highly consumed ready-to-eat salads. A total of 144 ready-to-eat salads from the Cypriot market were analyzed in an attempt to determine the effects of the expiration date on the microbial load and plant metabolic variables of the salads. Possible correlations between them were also investigated for the first time. Furthermore, the impacts of the season (winter, summer), salad producing companies and type of salad and/or their interactions with the tested parameters were investigated. Results revealed that the microbial load (mainly spoilage microorganisms, such as Pseudomonas spp., yeasts and molds) increased towards the end of the shelf life. The microbial load was differentiated among the five salad producers and/or the salad types, highlighting the importance of a common and safe sanitation-processing chain in the preparation of ready-to-eat salads. Summer was the season in which Escherichia coli counts were found to be higher for plain lettuce, while Staphylococcus spp. was increased numbers for the lettuce+endive/radicchio, lettuce+rocket and lettuce+chives type of salads. Additionally, an increased Staphylococcus spp. was observed for plain rocket salads in winter. All samples examined were found negative for Salmonella enterica and Listeria monocytogenes. Moreover, carbon dioxide production and damage indexes (hydrogen peroxide and lipid peroxidation) increased on expiration date on both winter and summer seasons, indicating plant tissue stress at the end of shelf life. These findings indicate that the expiration date and relevant shelf life of processed vegetables are important parameters to be considered when postharvest management is applied to these products, ensuring safety and quality.
Article
Consumption of phytochemicals-rich foods shows the health effect on some chronic diseases. However, the bioaccessibility of these phytochemicals is extremely low, and they are often consumed in the diet along with the food matrix. The food matrix can be described as a complex assembly of various physical and chemical interactions that take place between the compounds present in the food. Some studies indicated that the physiological response and the health benefits of phytochemicals are resultant in these interactions. Some food substrates inhibit the absorption of phytochemicals via this interaction. Moreover, processing technologies have been developed to facilitate the release and/or to increase the accessibility of phytochemicals in plants or breakdown of the food matrix. Food processing processes may disrupt the activity of phytochemicals or reduce bioaccessibility. Enhancement of functional and sensorial attributes of phytochemicals in the daily diet may be achieved by modifying the food matrix and food processing in appropriate ways. Therefore, this review concisely elaborated on the mechanism and the influence of food matrix in different parts of the digestive tract in the human body, the chemical interaction between phytochemicals and other compounds in a food matrix, and the various food processing technologies on the bioaccessibility and chemical interaction of dietary phytochemicals. Moreover, the enhancing of phytochemical bioaccessibility through food matrix design and the positive/negative of food processing for dietary phytochemicals was also discussed in this study.
Article
Flavonoids are one of the largest groups of plant secondary metabolites. They comprise several thousand compounds that share a phenylchromane skeleton and can be classified into different classes, namely flavones, flavonols, flavanones, flavanols, anthocyanins, dihydroflavonols, isoflavones, and chalcones. Flavonoids occur in their natural sources as aglycones or glycosylated forms and as monomers or constituting polymerized structures and can be found both as free and matrix‐bound compounds. This structural diversity affects their physicochemical behavior, and different flavonoid classes and compounds may have different requisites for their extraction and analysis, so that there is not a unique analytical strategy that applies in all situations. In this article, the main methodological approaches to the analysis of flavonoids in plant materials are revised. Particular attention is paid to more recent extraction techniques and high‐performance liquid chromatography (LC)‐based methodologies coupled to different detection systems, and especially liquid chromatography coupled to mass spectrometry (LC‐MS) that currently dominates the field of flavonoid analysis.
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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.
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The objective of the present study was to explore the effect of folic acid on the postharvest physiology of broccoli placed in storage. Broccoli heads were immersed in 5 mg L-1 folic acid for 10 min, then stored at 20 ± 1 °C for 4 days. Results indicated that the postharvest treatment of broccoli with folic acid decreased the rate of flower opening and yellowing, inhibited weight loss, reduced the level of respiration, as well as ethylene generation. Folic acid-treated broccoli maintained their level of chlorophyll, total soluble solids, vitamin C, total phenolics, flavonoids, glucosinolate, and folic acid. Treated broccoli also exhibited reduced accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS). Concomitantly, antioxidant enzyme activity and corresponding gene expression were also enhanced. In contrast, chlorophyll-degrading enzyme gene expression was suppressed. These results indicated that folic acid treatment of broccoli could be used to prolong shelf-life.
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BACKGROUND In recent years, protected crop production using plant factories to produce high‐value crops with greater functional components has become more popular in many countries. The quantification of the components, however, is mainly conducted by laboratory analyses, which are time‐ and labor‐consuming. This study was conducted to investigate the potential of non‐destructive diffuse reflectance spectroscopy technique to estimate functional components (i.e., glucosinolates, amino acids, sugars, and carotenoids) in the leaves of Chinese cabbage grown in a plant factory. RESULTS From the overall analysis, better estimations were obtained using the partial least square regression (PLSR) procedure. The important wavelengths for each functional component were identified mainly in the UV‐VIS regions. Identified wavelengths were 317, 390, 888, and 940 nm for sugars, 520 and 960 nm for amino acids, 385, 860, and 945 nm for glucosinolates, and 454, 472, and 530 nm for carotenoids. CONCLUSION Optical reflectance spectroscopy showed to be a potential as a tool for estimation of functional components in the leaves of Chinese cabbage. The results of the study would provide useful information for design and application of sensors to be used for on‐site quantification of the functional components. This article is protected by copyright. All rights reserved.
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The consumption of cruciferous vegetables lowers incidences of chronic diseases like cancer. Some of the major cruciferous vegetables consumed as fresh or cooked are broccoli, cabbage, cauliflower, Brussels sprouts etc. These vegetables contain biologically active compounds like glucosinolates and its derived isothiocyanates. Isothiocyanates are sulfur containing secondary metabolites and possess chemopreventive activity. This review provides information on glucosinolates and its derived isothiocyanates and with some insights on the mechanisms for cancer inhibition.
Chapter
This chapter provides an overview of phytochemicals in vegetables with insight into their distribution, chemical characteristics, bioactivities, and potential health effects. Vegetables are rich in phytochemicals that can reduce platelet aggregation, modulate synthesis and absorption of cholesterol, and reduce blood pressure. The composition and stability of plant-based bioactive compounds is highly diversified and contributes significantly to the apparent health benefits associated with these products. The content of phenolic compounds in vegetables is influenced by various factors, namely variety, climatic conditions and agricultural practices, maturity at harvest, and storage conditions. Phenolic compounds such as tannins have the ability to bind and precipitate macromolecules such as protein, carbohydrates, and digestive enzymes, thus causing harmful nutritional effects. Glucosinolates in Brassica vegetables confer defense functions to the plants and provide a source of bioactive compounds that are important to human nutrition and health.
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'Marathon' broccoli (Brassica oleracea L. var. italica) florets were stored in air, low O2 (0.25%, 0.5%, and 1%) or high CO2 (3%, 6%, and I0%) at 0, 5, and 10C. Oxygen consumption and CO2 production were reduced under low O2 or high CO2 atmosphere, the reduction being greater at lower O2 and higher CO2 levels. No differences were found in ethylene production among the different atmospheres. Low O2 and high CO2 retained color of broccoli florets to about the same extent at 10C but had no effect at 0 and 5C. Development of soft rot and browning was suppressed by low O2 or high CO2, but offensive off-odor occurred in 0.25% O2 at all temperatures and 0.5% O2 at 10C. These results indicate that the best O2 and CO2 levels seem to be 0.5% O2 and 10% CO2 at 0 and 5C, and 10% O2 and 10% CO2 at 10C.
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Controlled atmosphere (CA) conditions were assessed for long-term broccoli ( Brassica oleracea L. Italica Group) storage. Broccoli was stored for 6 weeks at 1C under N 2 containing the following percentages of CO 2 /O 2 : 0%/20%; 10%/20%; 6%/2.5%; I0%/2.5%; and 15%/2.5%. Color and chlorophyll retention was better under CA than in air. This improved retention was mainly due to increased CO 2 concentration. Storage under CA also delayed the development of soft rot and mold. However, after 6 weeks of storage under an atmosphere containing 10% or more CO 2 , the rate of respiration increased simultaneously with the development of undesirable odors and physiological injury. Among the atmospheres tested, 6% CO 2 and 2.5% O 2 was the best for long-term (>3 weeks) maintenance of broccoli quality while avoiding physiological injury.
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Broccoli (Brassica oleracea L. Italica Group) is an economically important vegetable crop and its consumption may benefit human health. Glucosinolates, a group of secondary plant metabolites found generally in the cultivated Brassicaceae, may protect against the development of certain malignancies. The objective of this study was to evaluate total and individual glucosinolate content of broccoli cultivars widely grown in southern Europe following spring vs. summer planting (early vs. late crop, respectively). Glucosinolates in primary and secondary inflorescences taken from mature plants were analyzed separately by high performance liquid chromatography (HPLC). The cultivars contained primarily 4-methylsulfinylbutyl-, indol-3-ylmethyl- and 1-methoxyindol-3-ylmethyl-glucosinolates. Total and individual glucosinolate levels varied significantly between seasons, among cultivars and between inflorescences. `Shogun' contained the highest total glucosinolate levels (between 35.2 mmol·kg-1 dry weight in primary inflorescences of the early crop and 47.9 in secondary inflorescences of the late crop). Total and individual glucosinolate levels were generally higher in the late than in the early crop. Primary inflorescences generally contained the highest glucosinolate levels in the early crop but secondary inflorescences had the highest levels in the late one.
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Broccoli is a very perishable vegetable with a high water content (around 88%) which leads to rapid dehydration and probably to an alteration in composition if conditions after harvest are not controlled. This study evaluates the glucosinolate pattern and glucosinolate levels in the principal and secondary inflorescences of fresh broccoli cv ‘Tokyodome’, and after being submitted to some situations which are likely to occur during or after harvest: room temperature (±20 °C) for 5 days, kept in the fridge at 4 °C for 5 days, and frozen after blanching. Another set of material was harvested 5 days later, simulating a post-maturation stage, and analysed. The highest total glucosinolate content was found at commercial maturation with 20 888 and 20 355 µmoles kg−1 DW in the principal and secondary inflorescences, respectively. Keeping the inflorescences at room temperature caused the most significant (P < 0.05) reductions in total and individual glucosinolates, except for 4-hydroxyindol-3-ylmethyl-, 2-hydroxy-2-phenylethyl- and 2-phenylethyl-, when compared to the other situations. The highest levels (10 925 µmoles kg−1 DW) of 4-methylsulphinylbutyl-, the precursor of the anti-cancer isothiocyanate sulphoraphane, were found in the inflorescences freshly harvested at commercial stage. Refrigeration at 4 °C and freezing were shown to be the best preservation processes for maintaining high levels of these and other glucosinolates in contrast with the other situations. © 1999 Society of Chemical Industry
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 The effect of modified-atmosphere packaging (MAP) on the amount of soluble phenolics in, and the visual appearance of, white, green and red tissues of minimally processed “Lollo Rosso” lettuce were evaluated. Minimal processing induced a two-fold increase in the amount of soluble phenylpropanoids in the midribs during storage in air at 5°C. When the lettuce was stored in the presence of 2–3% O2 and 12–14% CO2, this increase was not induced and no browning was observed. A particularly marked decrease in the amount of phenylpropanoids was observed in MAP-stored green and red tissues. The concentrations of flavonoids and anthocyanins did not change much in midribs and green tissues, while they were significantly degraded in red tissues under MAP conditions. MAP storage proved useful in the prevention of browning, the main cause of quality loss in minimally processed “Lollo Rosso” lettuce. However, MAP storage was not so beneficial for the preservation of the quality of red tissues and, in fact, their overall visual quality, texture, aroma and macroscopic breakdown under MAP conditions were worse than those of air-stored tissues.
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The effects of post-harvest and packaging treatments on glucoraphanin (4-methylsulfinylbutyl glucosinolate), the glucosinolate precursor of anticancer isothiocyanate sulforaphane [4-methylsulfinylbutyl isothiocyanate], were examined in broccoli (Brassica oleracea var. italica) during storage times. The results showed that at 20 degrees C, 55% loss of glucoraphanin concentration occurred in broccoli stored in open boxes during the first 3 days of the treatment and 56% loss was found in broccoli stored in plastic bags by day 7. Under both air and controlled atmosphere (CA) storage, glucoraphanin concentration appeared to fluctuate slightly during 25 days of storage and the concentrations under CA was significantly higher than those stored under air treatment. In modified atmosphere packaging (MAP) treatments, glucoraphanin concentration in air control packaging decreased significantly whereas there were no significant changes in glucoraphanin concentration in MAP with no holes at 4 degrees C and two microholes at 20 degrees C for up to 10 days. Decreases in glucoraphanin concentration occurred when the broccoli heads deteriorated. In the present study, the best method for preserving glucoraphanin concentration in broccoli heads after harvest was storage of broccoli in MAP and refrigeration at 4 degrees C. This condition maintained the glucoraphanin concentration for at least 10 days and also maintained the visual quality of the broccoli heads.
Article
The effect of modified-atmosphere packaging (MAP) on the amount of soluble phenolics in, and the visual appearance of, white, green and red tissues of minimally processed "Lollo Rosso" lettuce were evaluated. Minimal processing induced a two-fold increase in the amount of soluble phenylpropanoids in the midribs during storage in air at 5 °C. When the lettuce was stored in the presence of 2-3% O2 and 12-14% CO2, this increase was not induced and no browning was observed. A particularly marked decrease in the amount of phenylpropanoids was observed in MAP-stored green and red tissues. The concentrations of flavonoids and anthocyanins did not change much in midribs and green tissues, while they were significantly degraded in red tissues under MAP conditions. MAP storage proved useful in the prevention of browning, the main cause of quality loss in minimally processed "Lollo Rosso" lettuce. However, MAP storage was not so beneficial for the preservation of the quality of red tissues and, in fact, their overall visual quality, texture, aroma and macroscopic breakdown under MAP conditions were worse than those of air-stored tissues.
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The glucosinolate contents of (i) six lines of green-curded cauliflowers (Di Macerata), (ii) six lines of green-curded cauliflowers with pyramidal curds (Romanesco), and (iii) nine lines of purple-headed broccoli have been determined using high performance liquid chromatography. Total glucosinolate contents ranged between 18.4-42.8 mg 100 g -1 fresh weight (i), 27.0-41.6 mg 100 g -1 (ii), and 72.0-212.2 mg 100 g -1 (iii). Total glucosinolate contents of green-curded cauliflower are thus lower than previously determined in the normal white-curded varieties, whilst the levels in purple-headed broccoli are higher than those found in the green-headed calabrese types. 3-Methylsulphinylpropyl and indolyl-3-methyl glucosinolates were the major components of all three classes, with 4-methylsulphinylbutyl glucosinolate also being present in significant amounts in Romanesco and purple-headed broccoli. The levels of total and individual glucosinolates determined in this investigation are discussed in the context of other brassicas and the anticarcinogenic properties of these vegetables.
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Glucosinolates were evaluated in 5 groups and 65 accessions of Brassica oleracea (50 broccoli, 4 Brussels sprouts, 6 cabbage, 3 cauliflower, and 2 kale) grown under uniform cultural conditions. Glucosinolates and their concentrations varied among the different groups and within each group. The predominant glucosinolates in broccoli were 4-methylsulfinylbutyl glucosinolate (glucoraphanin), 3-butenyl glucosinolate (gluconapin), and 3-indolylmethyl glucosinoate (glucobrassicin). Glucoraphanin concentration in broccoli ranged from 0.8 mu mol g(-1) DW in EV6-1 to 21.7 mu mol g(-1) DW in Brigadier. Concentrations of the other glucosinolates in broccoli varied similarly over a wide range. In Brussels sprouts, cabbage, cauliflower, and kale, the predominant glucosinolates were sinigrin (8.9, 7.8, 9.3, and 10.4 mu mol g(-1) DW, respectively) and glucobrassicin (3.2, 0.9, 1.3, and 1.2 mu mol g(-1) DW, respectively). Brussels sprouts also had significant amounts of gluconapin (6.9 mu mol g(-1) DW). Wide variations in glucosinolate content among genotypes suggest differences in their health-promoting properties and the opportunity for enhancement of their levels through genetic manipulation.
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Content of total and individual glucosinolates were determined in, 'Marathon' broccoli florets (Brassica olerucea L. var. italica stored 7 days at 10C under air, 0.5% O 2, 0.5% O2 + 20% CO2 or 20% CO2 atmosphere, followed by transfer to air for 2 days. 'Marathon' broccoli contained glucoraphanin, glucobrassicin, neoglucobrassicin, glucoiberin, 4- methoxyglucobrassicin, progoitrin, glucoalyssin, and gluconasturtiin. The methylssulfinylalkylglucosinolates (glucoiberin and glucoraphanin) and the indol-3-ylmethylglucosinolates (glucobrassicin, neoglucobrassicin and 4- methoxyglucobrassicin) accounted for 78% and 20% of the total content, respectively, in freshly harvested broccoli. CA treatment and storage time had no significant effect on the relative content of these two groups of glucosinolates. Freshly harvested broccoli contained 47 µmol glucosinolate/g dry weight. The total glucosinolate content increased 42% and 21% during 7 days storage under air and 0.5% O2 + 20% CO2, respectively, as compared to freshly harvested broccoli, and decreased 15% in broccoli stored under 20% CO2. Treatment with 20% CO2 in the absence of 0, resulted in visible CO, injury and water soaking of the tissue. Aeration had no significant effect on total glucosinolate content but reduced the glucobrassicin content 35% in broccoli stored 7 days under 0.5% O 2 + 20% CO2 or 20% CO2atmosphere. In contrast, the 4-methoxyglucobrassicin content increased during storage under low O2 atmosphere and increased further after transfer to air.
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Five flavonoids from Swiss chard leaves (Beta vulgaris subsp. cycla) cultivar “green” were isolated and identified as vitexin 2‘‘-xyloside and its 6‘‘-malonated derivative, kaempferol 3-gentiobioside, isorhamnetin 3-gentiobioside, and isorhamnetin 3-vicianoside. 6‘‘-Malonyl-2‘‘-xylosyl vitexin is a new naturally occurring flavonoid. In fact, this is the first time that a flavonoid C-glycoside acylated with a dicarboxylic acid is reported in nature. The flavonoid content of fresh leaves (green cultivar) was in the range 2.4−3.0 mg/g fresh weight (f.w.). Cultivar “yellow” contained only flavone C-glycosides (2.1−2.3 mg/g f.w.), while the flavonols were not detected. Their vitamin C content was between 0.4 and 0.5 mg/g f.w., and after domestic processing an 80% loss was observed. Modified atmosphere packaging (MAP) (7% O2 and 10% CO2) had no effect on total flavonoid content after 8 days of storage, although it increased flavonoid extraction during cooking in boiling water. In contrast, vitamin C content decreased, especially in MAP-stored Swiss chard, to reach levels below 50% of the intial content after 8 days of cold storage. Keywords: Beta vulgaris subsp. cycla; Chenopodiaceae; Swiss chard; flavonoids; vitamin C; antioxidants; modified atmosphere packaging; cooking; minimally processed
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Minimally processed products are more perishable than unprocessed raw materials and readily deteriorate in quality, especially in color and texture. The effects of minimal processing on phenolic metabolites have been studied on red lettuce. Three different tissues of cv. Lollo Rosso were separated as white, green, and red and stored at 5 °C for 7−14 days. The phenolic acids caffeoyltartaric, chlorogenic, dicaffeoyltartaric, and dicaffeoylquinic, the flavonoids quercetin 3-glucuronide, quercetin 3-glucoside, quercetin 3-(6-malonylglucoside), and the new compound quercetin 3-(6-malonylglucoside) 7-glucoside, and the anthocyanin cyanidin 3-malonylglucoside were isolated and identified in lettuce extracts. Phenolic compound content was evaluated immediately after cutting and after storage of the minimally processed products at 5 °C. In midrib, wounding induced an increase in phenylpropanoids during storage, particularly phenolic acids and anthocyanins. On the contrary, wounding did not induce significant changes in the caffeic acid derivatives and flavonoids in green and red tissues. The anthocyanin content decreased in both green and red tissues during storage. Keywords: Lettuce; Lactuca sativa; Lollo Rosso; anthocyanins; phenolics; flavonoids; minimal processing; wound-induced changes; pigment stability; quality
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Carbon dioxide-enriched atmospheres are used to reduce the incidence and severity of decay and to extend the postharvest life of strawberries. The influence of CO2 on the postharvest quality parameters of strawberries, particularly the stability of anthocyanins and other phenolic compounds, was investigated. Freshly harvested strawberries were placed in jars ventilated continuously with air or air enriched with 10%, 20%, or 40% CO2 at 5 °C for 10 days. Samples were taken initially, and after 5 and 10 days of storage, and color (L* a* b* color space), pH, TA, TSS, and firmness were measured. Anthocyanins and other phenolics were analyzed by HPLC. Elevated CO2 degraded internal color while air-treated fruit remained red. Internal and external tissues differed in composition and concentration of phenolic compounds. CO2 had a minimal effect on the anthocyanin content of external tissues but induced a remarkable decrease in anthocyanin content of internal tissues. Factors, such as pH and copigmentation, that could explain this degradation are discussed. Keywords: Fragaria × ananassa; controlled atmosphere; quality parameters; anthocyanins; phenolics
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The stability of the major flavonol glucosides, quercetin 3,4‘-O-diglucoside (QDG) and quercetin 4‘-O-monoglucoside (QMG), was studied in two varieties of onion (Red Baron and Crossbow) that were cured and stored for 6 months under normal commercial conditons and analyzed at regular intervals. Onions were also cooked by boiling in water and by frying in oil under normal domestic conditions. Apart from a 50% loss of quercetin 4‘-O-monoglucoside during the initial drying process, little change in content and composition was observed over 6 months of storage. Neither boiling nor frying resulted in interconversion of the quercetin conjugates or production of free quercetin, although a 25% loss overall was recorded for each process. Keywords: Onion; Allium cepa; flavonol; quercetin; glucoside; HPLC; storage; processing
Article
Thirty six rapeseed samples from a factorial designed nitrogen and sulphur trial were analysed for total glucosinolate content by the X-ray fluorescence (X-RF) and HPLC methods and for protein content by the Kjeldahl method. Protein content varied from 16.0 to 22.6%. Correction for seed protein content in the calculation of glucosinolate content by X-RF significantly improved the agreement between the two methods of glucosinolate analysis. The following equation was used in the correction: Y = 14.99 [S(mg g−1)-protein %/7.5].
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Changes in the volatile chemicals produced on autolysis were monitored during the development of cauliflower, Chinese cabbage, fodder rape and radish. Compounds were identified from gas-liquid chromatography retention times, and mass spectrometry, seven of the mass spectrographs not having previously been recorded. Of the 23 compounds identified overall, 19 were extracted from seeds which, whether aged or freshly harvested, contained the maximum concentration of volatiles encountered. A rapid decrease in the concentrations of volatile hydrolysis products occurred during the first 4 weeks of development. Thereafter a steady increase and change in compounds was recorded, usually related to biologically significant events. The enzymic production of these volatile chemicals is discussed with respect to the action of thioglucosidase and epithiospecifier protein.
Article
Humans are unable to synthesise L-ascorbic acid (L-AA, ascorbate, vitamin C), and are thus entirely dependent upon dietary sources to meet needs. In both plant and animal metabolism, the biological functions of L-ascorbic acid are centred around the antioxidant properties of this molecule. Considerable evidence has been accruing in the last two decades of the importance of L-AA in protecting not only the plant from oxidative stress, but also mammals from various chronic diseases that have their origins in oxidative stress. Evidence suggests that the plasma levels of L-AA in large sections of the population are sub-optimal for the health protective effects of this vitamin.Until quite recently, little focus has been given to improving the L-AA content of plant foods, either in terms of the amounts present in commercial crop varieties, or in minimising losses prior to ingestion. Further, while L-AA biosynthesis in animals was elucidated in the 1960s,1 it is only very recently that a distinct biosynthetic route for plants has been proposed.2 The characterisation of this new pathway will undoubtedly provide the necessary focus and impetus to enable fundamental questions on plant L-AA metabolism to be resolved.This review focuses on the role of L-AA in metabolism and the latest studies regarding its biosynthesis, tissue compartmentalisation, turnover and catabolism. These inter-relationships are considered in relation to the potential to improve the L-AA content of crops. Methodology for the reliable analysis of L-AA in plant foods is briefly reviewed. The concentrations found in common food sources and the effects of processing, or storage prior to consumption are discussed. Finally the factors that determine the bioavailability of L-AA and how it may be improved are considered, as well as the most important future research needs.© 2000 Society of Chemical Industry
Article
Glucosinolates, phenolic compounds and vitamin C were evaluated in two commercial and 12 experimental cultivars of broccoli (Brassica oleracea L var italica) grown under uniform cultural conditions. The predominant glucosinolates in all broccoli cultivars were 4-methylsulphinylbutyl glucosinolate (glucoraphanin) and 3-indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates such as 4-OH-glucobrassicin and N-methoxyglucobrassicin were detected in lower amounts. The total glucosinolate concentration ranged from 3.0 µmol g−1 dw (dry weight) in Pentathlon (experimental cultivar) to 28.3 µmol g−1 dw in I-9905 (experimental cultivar). Flavonoids, caffeic acid derivatives and sinapic acid derivatives were quantified in methanol extracts. The largest content of flavonoids was found in the commercial cultivars Marathon and Lord, around 60 mg kg−1 fw (fresh weight). The vitamin C content of broccoli ranged from 43.1 mg per 100 g fw in Lord (commercial cultivar) to 146.3 mg per 100 g fw in SG-4515 (experimental cultivar).© 2002 Society of Chemical Industry
Article
The two main flavonol glycosides present in broccoli florets were identified as quercetin 3-O-sophoroside and kaempferol 3-O-sophoroside. Three minor glucosides of quercetin and kaempferol were also detected, namely isoquercitrin, kaempferol 3-O-glucoside and a kaempferol diglucoside. The sophorosides of quercetin and kaempferol were present in raw florets at a level of 65 mg kg−1 and 166 mg kg−1 fresh weight, respectively. The total content of quercetin and kaempferol glycosides expressed as aglycone was 43 and 94 μg g−1 fresh weight, respectively, and these agree with other recently published data. During the cooking process only 14–28% of the individual glucosides were retained in the cooked tissue, the remainder being largely leached into the cooking water with only a small loss attributed to the formation of the respective aglycones. © 1998 SCI.
Article
Detection was by UV absorbance (after pre-column derivatization of dehydroascorbic acid with 1,2-phenylenediamine). When absent, isoascorbic acid could be used as internal standard. Isocratic separation was accomplished in 11 min using the eluent, methanol-water (5:95, v/v) containing potassium dihydrogen phosphate (50 mM) and the counterion hexadecyltrimethylammonium bromide (5 mM). Sample preparation steps using Sep-pak C18 cartridge were minimal. Ten ppm could be detected for each compound with good reproducibility (c.v. <2%). The method was used to determine vitamin C content in selected foods and beverages.
Article
'Shogun' broccoli florets were film-wrapped and stored for 7 days at 1 C to simulate a maximum period of commercial shipment. After cold storage, florets were kept for 2.5 days at 20 C to simulate a retail sale period. For wrapping, polyvinyl chloride (PVC) 9 m thickness and low-density polyethylene (LDPE) 11, 15, and 20 m thickness were used. Soluble solids content, pH, titratable acidity, weight loss, physiological disorders, visual quality, and gas composition within packages were monitored. Gas composition (about 18% O2 and 1% CO2 during cold storage and about 16% O2 and 2-3% CO2 during shelf life), overall quality, and yellowing and browning of the florets were at similar levels among the films studied. However, weight loss was about sixty times lower for all LDPE films than for PVC film. After shelf life the best results were obtained by using 15 m LDPE. This polymeric film could be a good alternative to PVC for wrapping broccoli for commercial shipment purposes, particularly to those countries where use of PVC has been forbidden.
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
Consumer selection and consumption of lightly processed vegetables have dramatically increased over the last decade. However, more research is required to identify those storage conditions that will minimize nutrient and quality losses in these highly perishable products. The objective of our study was to assess a variety of postharvest storage treatments including: modified atmosphere packaging (MAP), ventpackaging (VP), and automatic misting (AM) on antioxidant vitamin quality, moisture, color retention, and peroxidase activity in broccoli florets over 6-day storage at 5 °C. Relative to the initial level, total carotenoids were retained fully in MAP samples, but a dramatic loss (42–57%) in total carotenoid was observed in all other treatments by 6 days. Vitamin C retention was best in MAP samples (~100%); however, control and VP samples retained only 14–46% of this vitamin. A slight increase was observed in vitamin E content in all treatments except MAP by 4 days, then decreased by day 6. Peroxidase activity increased significantly in non-packaged (NP) and VP samples over 6 days, but no change was measured in the MAP samples. MAP resulted in the best retention of antioxidant vitamins, moisture and color in lightly processed broccoli florets during postharvest storage.
Article
From the edible parts of the Spanish red onion (cultivar ‘Morada de Amposta’), the anthocyanins cyanidin 3-glucoside, cyanidin 3-arabinoside, cyanidin 3-malonyl-glucoside and cyanidin 3-malonylarabinoside and the flavonoids quercetin 3,4′-diglucoside, quercetin 7,4′-diglucoside, quercetin 3-glucoside, dihydro-quercetin 3-glucoside and isorhamnetin 4′-glucoside were identified. The amount of anthocyanins reached 233 mg kg−1 and that of the flavonoids 943 mg kg−1 fresh weight of onions. The onions were processed minimally to produce fresh ‘ready-to-eat’ shredded onion, and the stability of the anthocyanin pigments was evaluated during storage in perforated films for 7 days at 8 °C. After 1 day of storage, a slight increase in anthocyanins was observed, followed by a decrease, reaching the lower levels after 7 days of storage. In spite of the decrease in anthocyanins, the appearance of the commodity was acceptable after the storage period. The stability of the individual anthocyanins was very different, the malonated anthocyanins being much more stable than the corresponding non-acylated pigments. In addition, the arabinosides were shown to be less stable than the corresponding glucosides.
Article
In 1971-1973 at the third examination of the Basel Study started in 1959, the major antioxidant vitamins and carotene were measured in the plasma of 2974 men. A subsample and their families were reinvestigated in 1977-79. During the 12-y observation period (1973-85) 553 men died, 204 of cancer (lung cancer 68, stomach cancer 20; colon cancer 17, all other malignancies 99). We found significantly lower mean carotene levels for all cancer, bronchus cancer, and stomach cancer (all P less than 0.01) compared with the 2421 survivors. The relative risk of subjects with low carotene (less than 0.23 mumol/L) was significantly elevated (P less than 0.05) for lung cancer (Cox's model). Higher risks were noted for all cancer (P less than 0.01) if both carotene and retinol were low. Low plasma carotene which is known to reflect carotene intake is in our study associated with increased cancer risk.
Article
Plasma antioxidant vitamins A, C, and E and carotene were measured in a group of 2,974 men participating in the third examination of the prospective Basel Study in 1971-1973. In 1985, the vital status and mortality of all participants were assessed. A total of 204 men had died from cancer, including 68 with bronchus cancer and 37 with gastrointestinal cancer (20 with stomach cancer and 17 with large bowel cancer excluding cancer of the rectum). Overall mortality from cancer was associated with low mean plasma levels of carotene adjusted for cholesterol (p less than 0.01) and of vitamin C (p less than 0.01). Bronchus and stomach cancers were associated with a low mean plasma carotene level (p less than 0.01). Subjects with subsequent stomach cancer also had lower mean vitamin C and lipid-adjusted vitamin A levels than did survivors (p less than 0.05). After calculation of the relative risk using the Cox model with exclusion of mortality during the first 2 years of follow-up, low plasma carotene (below quartile 1) was associated with a significantly increased risk for bronchus cancer (relative risk (RR) = 1.8, p less than 0.05), low plasma levels of carotene and vitamin A with all cancers (RR = 2.47, p less than 0.01), and low plasma retinol in older subjects (greater than age 60 years) with lung cancer (RR = 2.17, p less than 0.05). Low levels of vitamin C increased the risk of stomach cancer (RR = 2.38) and gastrointestinal cancer (RR = 2.46) in older subjects, but only significantly with the inclusion of the first 2 years. The authors conclude that low plasma levels of antioxidant vitamins are associated with an increased risk of subsequent cancer mortality. This effect was stronger in men above age 60 years at blood sampling, and the effect seems to be site-specific.
Article
Modified atmospheres (MA), i.e., elevated concentrations of carbon dioxide and reduced levels of oxygen and ethylene, can be useful supplements to provide optimum temperature and relative humidity in maintaining the quality of fresh fruits and vegetables after harvest. MA benefits include reduced respiration, ethylene production, and sensitivity to ethylene; retarded softening and compositional changes; alleviation of certain physiological disorders; and reduced decay. Subjecting fresh produce to too low an oxygen concentration and/or to too high a carbon dioxide level can result in MA stress, which is manifested by accelerated deterioration. Packaging fresh produce in polymeric films can result in a commodity-generated MA. Atmosphere modification within such packages depends on film permeability, commodity respiration rate and gas diffusion characteristics, and initial free volume and atmospheric composition within the package. Temperature, relative humidity, and air movement around the package can influence the permeability of the film. Temperature also affects the metabolic activity of the commodity and consequently the rate of attaining the desired MA. All these factors must be considered in developing a mathematical model for selecting the most suitable film for each commodity.
Article
This review surveys the occurrence, analysis, and properties of glucosinolates and derived compounds in plants and products intended for humans and animal consumption. The paper, which includes references published in 1981, is also intended to compliment existing reviews on the chemistry of these sulfur‐containing natural products. Particular emphasis is placed upon members of the Brassica family because of their importance as vegetables, condiments, oilseeds, and animal feedingstuffs. Since much of the work considered here relates to glucosinolate decomposition products, biochemical information concerning the nature, occurrence, and properties of the glucosinolate‐degrading enzyme, myrosinase, is considered in Section III. The methods available for the chemical analysis of glucosinolates and their various breakdown products are discussed critically. Factors affecting the glucosinolate content of plants and plant products arc outlined in Section VII. Particular emphasis is placed upon the effect of processing on the concentration and nature of breakdown products and on the myrosinase activity. The role of glucosinolate breakdown products on flavor development is examined in Section VIII. The more general effects, both beneficial and adverse, of these compounds in food are discussed in Section X. Since such effects in animal feedingstuffs have been the subject of regular reviews, these are considered here only briefly. Contraindications in the literature are pointed out, areas which have been inadequately explored are highlighted, and suggestions are made for future research.
Article
We have tested the ability of a representative range of dietary glucosinolates and their breakdown products, found in high concentrations in cruciferous vegetables, to act as blocking agents against carcinogenesis by inducing the activity of the anticarcinogenic phase II marker enzyme quinone reductase in murine hepa1c1c7 cells. Breakdown of glucosinolates was catalysed by the endogenous plant enzyme thioglucoside glucohydrolase at neutral and acid pH. Only two unmodified glucosinolates, p-hydroxybenzyl and 2-hydroxybut-3-enyl, significantly induced quinone reductase activity. However, after enzymic hydrolysis at near-neutral pH, some of the glucosinolates yielded breakdown products that significantly induced quinone reductase in the order: 3-methylsulphinylpropyl→prop-2-enyl→pent-4enyl ∼ 2-phenylethyl ∼ benzyl → all others tested. Incubation with myrosinase at acidic pH resulted in induction of quinone reductase activity by the hydrolysis products of only three of the tested glucosinolates: 3-methylsulphinylpropyl∼ 2-phenylethyl → benzyl → all others, activity due to the two alkenyl compounds being lost. The results show that the potential cancer-blocking action of both intact and thioglucoside glucohydrolase-treated glucosinolates, as assessed by induction of phase II enzyme activity, is dependent on the nature of the side chain of the parent glucosinolate.
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
Glucosinolates were evaluated in 5 groups and 65 accessions of Brassica oleracea (50 broccoli, 4 Brussels sprouts, 6 cabbage, 3 cauliflower, and 2 kale) grown under uniform cultural conditions. Glucosinolates and their concentrations varied among the different groups and within each group. The predominant glucosinolates in broccoli were 4-methylsulfinylbutyl glucosinolate (glucoraphanin), 3-butenyl glucosinolate (gluconapin), and 3-indolylmethyl glucosinoate (glucobrassicin). Glucoraphanin concentration in broccoli ranged from 0.8 micromol g(-1) DW in EV6-1 to 21.7 micromol g(-1) DW in Brigadier. Concentrations of the other glucosinolates in broccoli varied similarly over a wide range. In Brussels sprouts, cabbage, cauliflower, and kale, the predominant glucosinolates were sinigrin (8.9, 7.8, 9.3, and 10.4 micromol g(-1) DW, respectively) and glucobrassicin (3.2, 0.9, 1.3, and 1.2 micromol g(-1) DW, respectively). Brussels sprouts also had significant amounts of gluconapin (6.9 micromol g(-1) DW). Wide variations in glucosinolate content among genotypes suggest differences in their health-promoting properties and the opportunity for enhancement of their levels through genetic manipulation.
Article
Eight varieties of lettuce (Lactuca sativum) and three varieties of endive (Cichorium endivia) were analyzed for flavonoid composition and content. Total flavonoid contents, expressed as units of aglycon for fresh material, were in the ranges of 0.3-229 microg/g for lettuce and 44-248 microg/g for endive. Five quercetin conjugates [quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin 3-O-glucuronide, quercetin 3-O-(6-O-malonyl)glucoside, and quercetin 3-O-rhamnoside] and luteolin 7-O-glucuronide were measured in the green-leafed lettuce and an additional two cyanidin conjugates [cyanidin 3-O-glucoside and cyanidin 3-O-[(6-O-malonyl)glucoside]] in the red-leafed varieties. Three kaempferol conjugates [kaempferol 3-O-glucoside, kaempferol 3-O-glucuronide, and kaempferol 3-O-[6-O-malonyl)glucoside]] were measured in each of the endive varieties. The presence and identity of kaempferol 3-O-(6-O-malonyl)glucoside in endive was shown for the first time. Shredding of lettuce leaf followed by exposure to light produced significant losses of the flavonoid moiety in the green oak leaf (94%), red oak leaf (43%), iceberg (36%), green batavia (25%), lollo biondo (24%), and lollo rosso (6%) samples, whereas cos and green salad bowl samples did not show an overall loss. Shredding of endive also produced loss of the flavonoid moiety in escarole (32%), fine frisee (13%), and coarse frisee (8%). Significant demalonation was observed for both the quercetin and cyanidin glucosides in lettuce, whereas a similar degradation of the kaempferol analogue was found in endive tissue. Storage of whole heads of both lettuce and endive in the dark at 1 degrees C and 98% humidity for 7 days resulted in losses of total flavonol glycosides in the range of 7-46%. The identification of the amounts, position of substitution, and nature of the sugars is important for understanding the potential bioavailability and biological activities of flavonoids in salads.