Article

Effects of Stir-Fry Cooking with Different Edible Oils on the Phytochemical Composition of Broccoli

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

Numerous epidemiological studies indicate that Brassica vegetables in general and broccoli in particular protect humans against cancer; they are rich sources of glucosinolates and possess a high content on flavonoids, vitamins, and mineral nutrients. The contents of total intact glucosinolates, total phenolics, vitamin C, and minerals (potassium, sodium, calcium, magnesium, iron, manganese, zinc, and copper) in the edible portions of freshly harvested broccoli (florets), which was subjected to stir-frying treatments, were evaluated. In the present work, the stir-fry cooking experiments were carried out using different edible oils from plant origin (refined olive oil, extra virgin olive oil, sunflower oil, peanut oil, soyabean oil, and safflower oil) known and used worldwide. Results showed that during stir-frying, phenolics and vitamin C were more affected than glucosinolates and minerals. Stir-fry cooking with extra virgin olive, soybean, peanut, or safflower oil did not reduce the total glucosinolate content of the cooked broccoli compared with that of the uncooked sample. The vitamin C content of broccoli stir-fried with extra virgin olive or sunflower oil was similar to that of the uncooked sample, but greater than those samples stir-fried with other oils.

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... The GLS identified in broccoli decrease when they undergo heat treatment (Cieslik et al. 2007;Conaway et al. 2000;Moreno et al. 2007;Oerlemans et al. 2006;Vásquez-Caicedo et al. 2007). Thus, total aliphatic GLS significantly lower by 55% in stir-fried cooking, 54% when boiled in water followed by frying, 60% cooked in microwave, and 41% boiled in water. ...
... The type of fat used in stir-frying or frying also influences the amount of GLS in broccoli. Some authors, such as Moreno et al. (2007), have investigated which fats from refined olive oil, extra virgin olive oil, sunflower oil, soybean oil, peanut oil, and safflower oil have the strongest impact on the amount of GLS in broccoli. When refined olive oil is used, GLS loss is 49%, and it is 37% in sunflower oil. ...
... Cooking time is also relevant, as are exposure times to high temperatures during cooking and long cooking times between preparing and eating food. All the factors that reduce vitamin C should, in turn, be reduced to a minimum Moreno et al. 2007). ...
Article
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Broccoli belongs to the Brassicaceae family and the Brassica genus, also designated crucifers, which has been linked to reduced risk of certain diseases for their content of compounds like glucosinolates (GLS) and vitamin C. Isothiocyanates, nitriles, and thiocyanates are degradation products of glucosinolates, are substances that protect cells against oxidative stress, and present many other health benefits. Vitamin C also contains antioxidant properties that contribute to the beneficial effects that broccoli have for health. The present paper is an overview of the reduction of secondary plant products, such as GLS and vitamin C, by cooking. Nonetheless, these concentrations can be modified if the cell structure of the plant is disrupted, e.g., while cutting, chewing, or cooking. Myrosinase can come into contact with GLS and hydrolyze it to isothiocyanate sulforaphane or sulforaphane nitrile, depending on the environmental conditions, which produces changes in the composition and concentration of GLS. Thus, cooking induces many chemical and physical modifications in food, among which GLS and vitamin C content in broccoli can change. Vitamin C and GLS are water-soluble, which makes them more susceptible to loss during the cooking process. Despite some controversy, most reviewed studies show that conventional cooking methods (boiling, steaming, and frying) and nonconventional ones (microwaving) significantly lead to the degradation of vitamin C and GLS. Nonetheless, steaming is the conventional method that obtains the best result to better preserve these two compounds.
... Una de las teorías dadas es que esta estabilidad se debe a que en la fritura, la temperatura interna de los alimentos nunca excede los 100°C, los tiempos de fritura son muy cortos, y la costra dura que se crea con el apanado retiene los líquidos de los alimentos. Sin embargo, la tiamina sigue siendo la vitamina que más pérdidas presenta (11,46,47,48). Una recopilación de los porcentajes de retención por fritura de algunas vitaminas hidrosolubles, se relaciona en la tabla 3. De igual manera, para vitamina C, se ha observado una alta inestabilidad dependiente del tipo de aceite utilizado para la fritura, siendo el aceite de oliva refinado el que muestra mayor perdida en brócoli frito, pero cuando se utilizó aceite de oliva extra virgen se presentó retención (47). ...
... Sin embargo, la tiamina sigue siendo la vitamina que más pérdidas presenta (11,46,47,48). Una recopilación de los porcentajes de retención por fritura de algunas vitaminas hidrosolubles, se relaciona en la tabla 3. De igual manera, para vitamina C, se ha observado una alta inestabilidad dependiente del tipo de aceite utilizado para la fritura, siendo el aceite de oliva refinado el que muestra mayor perdida en brócoli frito, pero cuando se utilizó aceite de oliva extra virgen se presentó retención (47). ...
... El efecto de la fritura de los alimentos sobre los minerales ha sido muy poco estudiado durante la cocción (2). Juárez y colaboradores (56) examinaron el efecto de la fritura de carne de cerdo apanada en abundante grasa sobre el contenido de Fe, Cu, Zn, Mg y Ca, reportando que el Ca y el Cu eran los minerales que más se retinen por fritura (97%), seguidos del Fe y el Mg (87%) y por último el Zn (75%), retención también observada en brócoli frito por Moreno y colaboradores (47). Al-Khalifa y Dawood (48) investigaron la retención de tiamina durante la cocción de pollo reportando altas pérdidas por fritura profunda, siendo mayor la pérdida en carnes de pollo donde hay menos irrigación sanguínea del ave, como la pechuga, que en carnes donde hay mayor irrigación, como muslos y contramuslos (retención del 28,2% y del 45,8% respectivamente). ...
Article
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La fritura es uno de los métodos de cocción más simples. Consiste en calentar aceite o grasa comestible entre 160 y 180°C e introducir el alimento para su cocción. Este método se caracteriza por formar una “costra” en la superficie del alimento y generar un sabor característico, agradable. Durante la fritura se presentan cambios en la composición nutricional de los alimentos, estos dependen del tipo de grasa, de las características propias del alimento, del tiempo, la temperatura y demás condiciones del proceso. Entre los cambios que más comúnmente se presentan está el aumento en el contenido de la grasa total o disminución, en el caso de los alimentos ricos en ésta con una tendencia similar al aceite o grasa utilizado. Con relación al contenido de vitaminas y minerales, las pérdidas de estos componentes son menores cuando se compara el método de fritura con otros métodos de cocción, debido a la rapidez del proceso. Durante el proceso de fritura también ocurren cambios indeseables como la formación de oxiesteroles por oxidación del colesterol cuando se fríen alimentos de origen animal o en grasa animal, y formación de acrilamidas, ambos compuestos relacionados con el aumento del riesgo de enfermedades crónicas no transmisibles como las cardiovasculares y el cáncer.
... Cooking conditions were determined by the nutritionists of our group based on traditional gastronomy. Additionally, an informal tasting panel (three trained people) assessed the final processed food in terms of sensorial features [19,20]. All the samples were cooked for 15 min, regardless of the cooking method, in order to make their effects comparable. ...
... For steaming, distilled water (500 mL) was added to a stainless-steel steamer, which was covered with a lid until reaching 98 °C ± 2 °C; then the vegetables were introduced, with the temperature maintained during the whole process. Finally, 15 mL of extra virgin olive oil was preheated to 120 °C in a sauce pan, for stir-frying, and then samples were added [20]. Each process was performed three times for the three cooking methods. ...
Article
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Brassica vegetables are of great interest due to their antioxidant and anti-inflammatory activity, being responsible for the glucosinolates (GLS) and their hydroxylated derivatives, the isothiocyanates (ITC). Nevertheless, these compounds are quite unstable when these vegetables are cooked. In order to study this fact, the influence of several common domestic cooking practices on the degradation of GLS and ITC in two novel Brassica spp.: broccolini (Brassica oleracea var italica Group x alboglabra Group) and kale (Brassica oleracea var. sabellica L.) was determined. On one hand, results showed that both varieties were rich in health-promoter compounds, broccolini being a good source of glucoraphanin and sulforaphane (≈79 and 2.5 mg 100 g−1 fresh weight (F.W.), respectively), and kale rich in glucoiberin and iberin (≈12 and 0.8 mg 100 g−1 F.W., respectively). On the other hand, regarding cooking treatments, stir-frying and steaming were suitable techniques to preserve GLS and ITC (≥50% of the uncooked samples), while boiling was deleterious for the retention of these bioactive compounds (20–40% of the uncooked samples). Accordingly, the appropriate cooking method should be considered an important factor to preserve the health-promoting effects in these trending Brassica.
... have a high content of antioxidants including carotenes, DL-α-tocopherol and ascorbate, associated with reduced cardiovascular diseases and certain cancers. Mineral content of broccoli remained unaffected by cooking, with cooked florets containing the recommended daily allowance (RDA) per portion size of all 8 minerals examined including Zn (USA RDA levels) (Moreno et al., 2007). Natural synergistic reactions among these phyto-minerals and vitamins have been demonstrated to reduce the likelihood of consumers developing many cancers and diseases (Palozza and Krinsky, 1992). ...
... Natural synergistic reactions among these phyto-minerals and vitamins have been demonstrated to reduce the likelihood of consumers developing many cancers and diseases (Palozza and Krinsky, 1992). Moreno et al. (2007) concluded, that exploiting natural concentration of phytonutrients through crop breeding, increased production and consumption may better serve human health, than the addition of reduced bio-available elements in supplements or salts. ...
Article
Zinc (Zn) is an essential plant nutrient. Most plant species have a shoot Zn concentration ([Zn]shoot) 10 mg Zn g-1 DW. There is compelling evidence that orthologues of the Arabidopsis thaliana PIB-type Heavy-Metal-Associated domain-containing ATPase 4 (AtHMA4), which transport Zn2+ and other cations, have a major involvement in the Zn hyperaccumulation trait. The aim of this thesis was to study aspects of genetic variation in the Brassicaceae using a comparative genomic approach, focussing primarily on orthologues of AtHMA4 in Noccaea and Brassica. The first major objective was to clone the full genomic sequence of NcHMA4. This locus was successfully sequenced in Noccaea caerulescens Saint Laurent Le Minier. First, a new genomic fosmid library was generated comprising 36,864 clones with 40 kb inserts, giving ~5-fold genomic coverage. Through DNA fingerprinting, Genome Sequencer (GS) FLX 454 sequencing and contig assembly, a single region collinear with AtHMA4 flanking genes was identified. Unlike A. thaliana, four novel tandem HMA4 gene repeats with highly conserved coding regions, but substantially divergent promoter regions, were present. Preliminary evidence indicates cis-regulated high expression, supporting previous expression data for N. caerulescens. Notably, this observation is remarkably consistant with recent findings in A. halleri. In planta analysis of NcHMA4 remains challenging in N. caerulescens due to a vernal obligate lengthy life cycle (7–9 months) and lack of a robust transformation system. To facilitate future analyses, genetically-stable faster cycling M4 lines were therefore created using fast neutron (FN) mutagenesis. Two non vernal obligate lines have been characterised bearing fruit as soon as 92 days after sowing (DAS) and showing no perturbed [Zn]shoot or obvious pleiotropic effects. Future efforts should focus on their efficient transformation to improve future in planta biological understanding. In Brassica, data from previously reported glasshouse and field studies on B. oleracea L. [Zn]shoot were further analysed to test for the presence of HMA4 orthologues in QTL regions. However, large QTL and multiple paralogues have hindered progress. A more efficient Targeting Induced Local Lesions In Genomes (TILLing)-based approach has therefore been pursued in B. rapa during the latter stages of this study. Locus specific allelic variants in a candidate metal transporter gene BraA.CAX1.a have been identified and methods for rapid downstream genotyping (High Resolution Melt (HRM)-based efficient SNP detection technology) and characterisation have been developed successfully. These approaches are now underway for BraA.HMA4 and an additional candidate metal transporter BraA.ESB1. Since A. thaliana knock-outs of ESB1, CAX1 and HMA genes have altered nutritional phenotypes, future studies will focus on their characterisation under contrasting mineral environments. This thesis has pursued a comparative genomics approach. A previously unreported quadruplication and cis-regulation probably contributes to high HMA4 expression in N. caerulescens. Fast cycling Noccaea lines and a robust Brassica genotyping platform were developed. These will become valuable tools for downstream molecular genetic approaches for in planta functional analysis of HMA4 and other transporters to determine their role in regulating mineral accumulation in Brassicaceae. Ultimately, a greater understanding of genetic variation in [Zn]shoot may have downstream application in genetic biofortification or phytoremediation strategies.
... The initial total vitamin C content (1,736.6 mg kg −1 fw) generally decreased after all cooking methods, except for frying (Fig. 3). Moreno et al. (2007) found that vitamin C of conventional Nubia broccoli did not decrease after stirfrying for 3 min and 3 s in extra virgin olive oil at 125-140°C. Vitamin C content dropped between 40 and 80 % when using soy, peanut, safflower and refined olive oil. ...
Article
The microbial, physical, sensory and nutritional quality of boiled (vacuum and conventional), steamed, pressure cooked, sous vide, microwaved (sous vide and conventional), deep-fried (vacuum and conventional) and grilled kailan-hybrid broccoli (Bimi®) after cooking was studied. Sous vide microwaving greatly decreased microbial counts, achieving very low psychrophilic and enterobacteria counts (1.1 and 0.2 log CFU g−1, respectively). Vacuum boiling and sous vide reduced the stem broccoli firmness by approximately 54–58 %, reaching a pleasant and moderate softening. Sous vide, grilling and steaming induced the lowest stem colour changes. Generally, all cooking treatments showed a good overall sensory quality. The total phenolic content (1,148 mg CAE kg−1 fw) usually increased after cooking, with microwave and grilled treatments registering the highest increases up to 2-fold. Commonly, the total antioxidant capacity (296.6 mg AAE kg−1 fw) increased after cooking by sous vide, microwaving and frying treatments registering the highest increments, by approximately 3.6-fold. Generally, the cooking process reduced the initial vitamin C content, with vacuum and conventional boiling showing the lowest and highest losses with 27 and 62 %, respectively, while vacuum deep frying preserved the initial value (1,737 mg kg−1 fw). As a main conclusion, the studied grilling and vacuum-based cooking treatments resulted in better microbial quality, colour, stem firmness and sensory quality than the remaining ones. This maintained or even improved the total antioxidant content of the new kailan-hybrid broccoli studied.
... The decreases registered reached the 8 and 81% for extra virgin olive oil and refined olive oil, respectively. (Moreno et al., 2007b). Steaming, by the contrary, has been shown as the thermal cooking process that causes the lowest vitamin C loss in Brassica foods (Vallejo et al., 2002a;Volden et al., 2009;Francisco et al., 2010). ...
Article
Full-text available
Brassica genus includes known horticultural vegetables with major economical importance worldwide, and involves vegetables of economical importance being part of the diet and source of oils for industry in many countries. Brassicales own a broad array of health-promoting compounds, emphasized as healthy rich sources of vitamin C. The adequate management of pre- and postharvest factors including crop varieties, growth conditions, harvesting, handling, storage, and final consumer operations would lead to increase or preserve of the vitamin C content or reduced losses by interfering in the catalysis mechanisms that remains largely unknown, and should be reviewed. Likewise, the importance of the food matrix on the absorption and metabolism of vitamin C is closely related to the range of the health benefits attributed to its intake. However, less beneficial effects were derived when purified compounds were administered in comparison to the ingestion of horticultural products such as Brassicas, which entail a closely relation between this food matrix and the bioavailability of its content in vitamin C. This fact should be here also discussed. These vegetables of immature flowers or leaves are used as food stuffs all over the world and represent a considerable part of both western and non-Western diets, being inexpensive crops widely spread and reachable to all social levels, constituting an important source of dietary vitamin C, which may work synergistically with the wealth of bioactive compounds present in these foods.
... The decreases registered reached the 8 and 81% for extra virgin olive oil and refined olive oil, respectively. (Moreno et al., 2007b). Steaming, by the contrary, has been shown as the thermal cooking process that causes the lowest vitamin C loss in Brassica foods (Vallejo et al., 2002a;Volden et al., 2009;Francisco et al., 2010). ...
... Stir-frying using refined olive and sunflower oils reduced total GLS content in broccoli florets significantly by 49% and 37%, respectively, with respect to the uncooked controls. Meanwhile, stir-frying using extra virgin olive, soybean, peanut, or safflower oils relatively gave no significant effect on the GLS content (Moreno et al., 2007). The authors, however, did not observe relationship between the cooking temperature or the lipid composition of the oils and the exerted effect on the GLS contents. ...
Article
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Abstract Brassica vegetables are consumed mostly after processing, which is expected to give beneficial effects on the vegetable properties, such as improved palatability and bioavailability of nutrients, or shelf life extension. But, processing also results to various changes in the content of health promoting phytochemicals like glucosinolates. This paper reviews the effects of processing on the glucosinolates content by using a mechanism approach underlying processing method employed. Cultural differences between Eastern and Western preparation practices and their possible effect on glucosinolate retention are highlighted. Boiling and blanching considerably reduce the glucosinolate content mainly due to mechanisms of cell lysis, diffusion, and leaching, and partly due to thermal and enzymatic degradation. Steaming, microwave processing, and stir frying either retain or slightly reduce the glucosinolates content due to low degrees of leaching; moreover these methods seem to enhance extractability of glucosinolates from the plant tissue. Fermentation reduces the glucosinolate content considerably but, the underlying mechanisms are not yet studied in detail. Studying the changes of glucosinolates during processing by a mechanistic approach is shown to be valuable to understand the impact of processing and to optimize processing conditions for health benefits of these compounds.
... Most bioactive compounds remain stable (Puupponen-Pimiä et al. 2003).Boiling for a typical time period causes a loss of 56% of the folate in broccoli while steaming causes no significant loss (McKillop et al. 2002). Broccoli florets lightly stir-fried in extra virgin olive oil or sunflower oil retain similar glucosinolate and vitamin C levels as uncooked ones (Moreno et al. 2007). Natural phytonutrients derived from cruciferous vegetables such as broccoli, kale, Brussels sprouts and watercress offer powerful, broad spectrum support for maintaining healthy estrogen metabolism and protecting against the ubiquitous, cancer-provoking agents encountered every day in our environment. ...
Article
Cancer Preventing Properties of Cruciferous Vegetables Health-promoting phytonutrients in cruciferous vegetables have been gaining attention for their powerful effects in combating cancer. This review concerns anticancer properties of cruciferous green vegetables of "Brassica" genus such as broccoli, kale, Brussels sprouts, watercress. The role and mechanisms of action of cruciferous active compounds such as sulforaphane, indole-3-carbinol, diindolylmethane and phenethyl isothiocyanate in protection against cancer and cancer-fighting are discussed. Losses of nutrients and active compounds during cooking, microwaving, and blanching of vegetables which may be more substantial than commonly perceived are also reviewed.
... Bongoni et al. [199] also reported that steaming increased total glucosinolates' level by 17 % at the end of cooking, which may be attributed to an increase in the extractability of glucosinolates by processing rather than a real increase in their total content. In addition, the contents of phytochemicals including glucosinolate were evaluated when fresh broccoli florets were subjected to stir-frying treatments in various edible oils, and the results indicated that glucosinolate in broccoli stir-fried with extra-virgin olive, soybean, peanut, or sunflower oil was similar to that in the uncooked sample [204]. We compared the effect of all five domestic cooking methods on the retention of glucosinolates in broccoli and found that stir-frying and stir-frying/boiling presented the highest loss of glucosinolates while steaming resulted in the lowest loss [202]. ...
Chapter
Full-text available
Broccoli is a rich source of health-promoting antioxidants and anticarcinogenic glucosinolates, which has long been recognized for their outstanding benefits to human nutrition and plant defense. The composition and content of glucosinolate are closely associated with the flavor and anticancer activity of broccoli. Up to now, broccoli is among a few Brassica vegetables, in which the biosynthetic pathway of glucosinolate has been widely studied and has attracted extensive attention. Recent studies in glucosinolate research have also identified the genetic variations, as well as the functions of individual glucosinolate profiles and their degradation products in broccoli, which provide the basic aims and powerful strategies for breeding of broccoli varieties with optimal glucosinolate composition and content. To fully exploit the potentially beneficial effects of broccoli, it is important to investigate the glucosinolate variation and metabolism across the whole food chain, from preharvest production to post-harvest storage, processing, and cooking. This chapter provides a general overview of glucosinolate biosynthetic pathway, as well as the genetic variation and function of individual glucosinolate profiles in broccoli, highlights the recent advances in glucosinolate accumulation of broccoli upon different preharvest and post-harvest handlings, and discusses their potential application in broccoli breeding, production, storage, processing, and consumption.
... For that reason, the amount of cooking water should be as low as possible and may be used for preparation of a sauce or soup to save the glucosinolates. There is a study of broccoli stir frying that produced some fairly encouraging results with respect to nutrient retention in broccoli [59]. Results showed that during stir frying, phenolics and vitamin C were more affected than glucosinolates and minerals. ...
Article
Full-text available
The plant family Brassicaceae, formerly Cruciferae, contains mustard oil glycosides, from which mustard oils are enzymatically hydrolyzed. Mustard oils offer protection from pests, microorganisms and fungi. More than 120 different mustard oils with various biological functions are known. Since ancient times, these substances are used as natural antibiotics, antiviral drugs and antimycotics. The antioxidative effect of mustard oils contributes to protection from DNA damage. Epidemiological and experimental studies have shown preventive and therapeutic effects of crucifers or isolated substances thereof. Particularly well studied is the mustard oil sulforaphane, which is contained in high concentrations in broccoli and its sprouts. As has been shown in mice recently, sulforaphane also targets the most malignant cancer stem cells, which are not affected by conventional cancer treatments. Based on these promising results, the first prospective clinical studies with cancer patients and sulforaphane-enriched broccoli sprouts have now been initiated in the United States.
... This increase in rosmarinic acid content could play an important role, due to exhibiting stronger antioxidant activity than caffeic acid or chlorogenic acid (Guillot et al., 1996;Kim et al., 2006). The results of the present study were opposite to those of Moreno et al. (2007), who reported that total phenolics of 3.5 min stir-fried broccoli exhibited a reduction compared to uncooked broccoli. It cannot be absolutely concluded that cooking in oil for a short time would increase the total phenolic content in all kinds of vegetables. ...
Article
Five different cooking methods - blanching, boiling, steaming, sautéing and high temperature (121°C) cooking - were applied to Ocimum herbs. Four Ocimum species - O. americanum (hairy basil), O. tenuiflorum (holy basil; syn. O. sanctum), O. basilicum (sweet basil) and O. gratissimum (wild basil) - were used to determine the effect of heating on their antioxidant capacity, total phenolic content, and presence of phytochemicals. Cooking with excess water, blanching, and boiling resulted in a reduction in both antioxidant capacity and phenolic content. HPLC chromatograms revealed that rosmarinic acid leached from the sweet basil leaves into the cooking water, in which sinapic acid was also detected. Meanwhile sautéing, as well as steaming at atmospheric and high pressures respectively, generally enhanced the antioxidant capacity of Ocimum, which was related to an increase in phenolic content. Similar chromatograms were detected in fresh, atmospheric steamed, and sautéed leaves, although the intensity varied. A major compound of the studied Ocimum herbs, rosmarinic acid, although found to increase in sautéed leaves, was substantially minimized in leaves steamed under pressure.
... Among all the studied cooking methods, stir-frying resulted in significantly greater losses of GSL than steaming or microwaving, which agrees with previous reports. A study on the effect of different types of cooking oil on GSLs in stir-fried broccoli resulted in up to 49% losses, irrespective of the cooking oil used [70]. Xu et al. [30] also reported a 77% loss in GSL concentration after stir-frying red cabbage while there was no significant loss in GSL content when green cabbage was stir-fried for 5 min [29]. ...
Article
Full-text available
Glucosinolate hydrolysis products are responsible for the health-promoting properties of Brassica vegetables. The impact of domestic cooking on the myrosinase stability, glucosinolates and hydrolysis products in 18 cabbage accession was investigated. Cabbages were steamed, microwaved, and stir-fried before analysis. Cooking significantly affected myrosinase stability and glucosinolate concentrations within and between cabbage morphotypes. Myrosinase was most stable after stir-frying, with up to 65% residual activity. Steaming and microwaving resulted in over 90% loss of myrosinase activity in some accessions. Stir-frying resulted in the greatest decrease in glucosinolate concentration, resulting in up to 70% loss. Steamed cabbages retained the highest glucosinolates after cooking (up to 97%). The profile and abundance of glucosinolate hydrolysis products detected varied across all cooking methods studied. Cooking reduced the amounts of nitriles and epithionitriles formed compared to raw samples. Steaming led to a significant increase in the concentration of beneficial isothiocyanates present in the cabbage and a significantly lower level of nitriles compared to other samples. Microwaving led to a reduction in the concentrations of both nitriles and isothiocyanates when compared to other cooking methods and raw cabbage. The results obtained help provide information on the optimal cooking methods for cabbage, suggesting that steaming may be the best approach to maximising beneficial isothiocyanate production.
... Bongoni et al. [199] also reported that steaming increased total glucosinolates' level by 17 % at the end of cooking, which may be attributed to an increase in the extractability of glucosinolates by processing rather than a real increase in their total content. In addition, the contents of phytochemicals including glucosinolate were evaluated when fresh broccoli florets were subjected to stir-frying treatments in various edible oils, and the results indicated that glucosinolate in broccoli stir-fried with extra-virgin olive, soybean, peanut, or sunflower oil was similar to that in the uncooked sample [204]. We compared the effect of all five domestic cooking methods on the retention of glucosinolates in broccoli and found that stir-frying and stir-frying/boiling presented the highest loss of glucosinolates while steaming resulted in the lowest loss [202]. ...
Chapter
Broccoli is a rich source of health-promoting antioxidants and anticarcinogenic glucosinolates, which has long been recognized for their outstanding benefits to human nutrition and plant defense. The composition and content of glucosinolate are closely associated with the flavor and anticancer activity of broccoli. Up to now, broccoli is among a few Brassica vegetables, in which the biosynthetic pathway of glucosinolate has been widely studied and has attracted extensive attention. Recent studies in glucosinolate research have also identified the genetic variations, as well as the functions of individual glucosinolate profiles and their degradation products in broccoli, which provide the basic aims and powerful strategies for breeding of broccoli varieties with optimal glucosinolate composition and content. To fully exploit the potentially beneficial effects of broccoli, it is important to investigate the glucosinolate variation and metabolism across the whole food chain, from preharvest production to post-harvest storage, processing, and cooking. This chapter provides a general overview of glucosinolate biosynthetic pathway, as well as the genetic variation and function of individual glucosinolate profiles in broccoli, highlights the recent advances in glucosinolate accumulation of broccoli upon different preharvest and post-harvest handlings, and discusses their potential application in broccoli breeding, production, storage, processing, and consumption.
... Broccoli can be suggested as a 'good source' of Ca and Mg for human nutrition, with comparable bioavailability to that of milk, and therefore, may be considered an important alternative source of Ca in those population groups with limited access or intake of dairy products [56]. Different cooking methods (boiling, steaming, microwaving and frying) not affected significantly to the mineral content of broccoli florets; therefore, on average, an edible portion (200g of raw broccoli) could provide, over 20% of the daily requirements of minerals [21,57]. ...
Chapter
Full-text available
This work provides an up to date review of the information available about bioactive compounds present in the Brassicaceaefamily (glucosinolates, phenolics and vitamins) in relation to human health. The phytochemical wealth of Brassica foods is gathering attention from the scientific community for being potentially protective for the cardiovascular system and against certain types of cancer, and neurological disorders, mainly because of their antiinflammatory and antioxidant properties. Even it is not yet possible to recommend a particular “daily dose” for human consumption of cruciferous foods for disease prevention, there is growing evidence regarding the protective effects of Brassica bioactive compounds for health via regulation of signaling pathways and cellular metabolism.
... The decreases registered reached the 8 and 81% for extra virgin olive oil and refined olive oil, respectively. (Moreno et al., 2007b). Steaming, by the contrary, has been shown as the thermal cooking process that causes the lowest vitamin C loss in Brassica foods (Vallejo et al., 2002a;Volden et al., 2009;Francisco et al., 2010). ...
... Therefore increasing the bioavailable levels of phytonutrients through crop breeding, may better serve human health, more economically and capillary than the addition of reduced elements in supplements or salts [10]. ...
Article
Zn deficiency is currently listed as a major risk factor for human health. Recently, a complimentary solution to mineral malnutrition termed ‘biofortification’ has been proposed. The aim of this study was to investigate the possible effects of a Zn-biofortification program on Zn levels, amino acidic profile and the phytochemicals content in an edible leafy vegetable, such as Brassica oleracea cv. Bronco. Our results indicate that supplementation of 80–100 μM Zn is optimal for maintaining the normal growth of plants and to promote the major Zn concentration in the edible part of B. oleracea. Any further increase of Zn supply induced an accumulation of total amino acids, and increased the enzymatic activities involved in sulfur assimilation and synthesis of phenols, finally resulting in a foliar accumulation of glucosinolates and phenolic compounds. Thus, it could be proposed that the growth of B. oleracea under 80–100 μM Zn may increase the intake of this micronutrient and other beneficial compunds for the human health.
... 6 The content of bioactive compounds in Brassicaceae vegetables varies with genotype, 7,8 environmental stress, 9 growth conditions, 10 and storage, processing, and cooking methods. 11,12 Phenolic compounds and glucosinolates are present in high amounts in seeds and during the first days of germination, reaching a 10-fold increase compared to commercial adult plants. 13 Glucosinolates, nitrogen−sulfur compounds (β-D-thioglucoside-n-hydroxysulfates), are classified as aliphatic (the major group in almost all crucifer seeds and sprouts of B. oleraceae, B. napus, B. rapa, and R. sativus), indolic (representing lower amounts in the glucosinolate profile), or aromatic (characteristic in S. alba and L. sativum. ...
Article
Cruciferous foods (Brassicaceae spp.) are rich in nutrients and bioactive compounds. Edible sprouts are becoming popular fresh foods and therefore, the phytochemical profiling of 9 varieties of Brassicaceae (broccoli, kohlrabi, red cabbage, rutabaga, turnip, turnip greens, radish, garden cress and white mustard) was evaluated for this purpose. The glucosinolates in seeds were significantly higher than in sprouts and the day 8 of germination was considered the optimum for consumption. The sprouts with higher concentrations of glucosinolates in 8-day old sprouts were white mustard, turnip and kohlrabi (~815 mg100 g-1 F.W., ~766 mg100 g-1 F.W. and ~653 mg100 g-1 F.W., respectively). Red cabbage and radish presented great total glucosinolates content (~516 mg100 g-1 F.W. and ~297 mg100 g-1 F.W., respectively in 8 day-old sprouts) and also higher total phenolic contents, biomass and antioxidant capacity. The selection of the best performers in terms of germination quality and phytochemical composition is the key to optimize new fresh and rich foods, enriched in health bioactive compounds. Further research of bioavailability of the bioactive compounds in Brassica foods will allow to backed recommendations for dietary effective dosages for nutrition and health.
... The initial total vitamin C content (1,736.6 mg kg −1 fw) generally decreased after all cooking methods, except for frying (Fig. 3). Moreno et al. (2007) found that vitamin C of conventional Nubia broccoli did not decrease after stirfrying for 3 min and 3 s in extra virgin olive oil at 125-140°C. Vitamin C content dropped between 40 and 80 % when using soy, peanut, safflower and refined olive oil. ...
Chapter
The microbial, physical, sensory and nutritional quality of boiled (vacuum and conventional), steamed, pressure cooked, sous vide, microwaved (sous vide and conventional), deep-fried (vacuum and conventional) and grilled kailan-hybrid broccoli (Bimi®) after cooking was studied. Sous vide microwaving greatly decreased microbial counts, achieving very low psychrophilic and enterobacteria counts (1.1 and 0.2 log CFU g −1 , respectively). Vacuum boiling and sous vide reduced the stem broccoli firmness by approximately 54–58 %, reaching a pleasant and moderate softening. Sous vide, grilling and steaming induced the lowest stem colour changes. Generally, all cooking treatments showed a good overall sensory quality. The total phenolic content (1,148 mg CAE kg −1 fw) usually increased after cooking, with microwave and grilled treatments registering the highest increases up to 2-fold. Commonly, the total antioxidant capacity (296.6 mg AAE kg −1 fw) increased after cooking by sous vide, microwaving and frying treatments registering the highest increments, by approximately 3.6-fold. Generally, the cooking process reduced the initial vitamin C content, with vacuum and conventional boiling showing the lowest and highest losses with 27 and 62 %, respectively, while vacuum deep frying preserved the initial value (1,737 mg kg −1 fw). As a main conclusion, the studied grilling and vacuum-based cooking treatments resulted in better microbial quality, colour, stem firmness and sensory quality than the remaining ones. This maintained or even improved the total antioxidant content of the new kailan-hybrid broccoli studied.
... Currently, the heat cooking mainly includes boiling, steaming, frying, baking, and microwave technology (Palermo et al., 2013). Studies showed that the loss of flavonols in foods increased during boiling, frying, and microwave ovens (Moreno, López-Berenguer, & García-Viguera, 2007;Zhao et al., 2019). Interestingly, different higher baking conditions did not lead to the degradation of flavonols (Yang et al., 2019). ...
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To prevent oxidation and maintain the quality of meat products, it is essential to add antioxidants. The aim of this work was to investigate the antioxidant activity of vine tea (Ampelopsis grossedentata) extract (VTE) and evaluate the effects of VTE on the quality characteristics and lipid and protein oxidation of cooked mixed pork patties during refrigerated storage. VTE had a significant DPPH radical scavenging activity, and its IC50 was 15.35 µg/ml. VTE‐treated mixed pork patties had a better texture than that of the control group (p < 0.05). VTE could significantly inhibit an increase in the TBARS value and the formation of carbonyl compounds (p < 0.05), and the inhibition was stronger than that of the butylated hydroxytoluene (BHT) group (p < 0.05), while the amount of sulfhydryl groups significantly decreased (p < 0.05). The color of VTE itself made the mixed pork patties darker (p < 0.05), but this did not affect the sensory scores and overall acceptability of the VTE‐treated patties, indicating the VTE can be incorporated into mixed pork patties. The scanning electron microscopy (SEM) results showed that the VTE inhibited the oxidation of the cooked mixed pork patties during refrigerated storage. These findings may be significant to helping extend the shelf life of meat products. The vine tea (Ampelopsis grossedentata) extract (VTE) could inhibit lipid and protein oxidation of cooked mixed pork patties during refrigerated storage. VTE can be used as an effective antioxidant.
... The absorption of these antioxidants into the food gives the food a better nutritional profile. For this reason, the use of EVOO is a healthier option than using other oils with less bioactive components [13,42,43]. ...
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Mediterranean cultures have used Extra Virgin Olive Oil (EVOO) as the only source of cooking oil for centuries, with their diet showing the highest amount of scientifically proven health benefits. However, there is a common misconception that EVOO is not suitable for cooking given its relatively lower smoke point, despite no scientific evidence that support this. This chapter aims to provide an overview of how EVOO is healthier, safer, and more stable to cook with than other common edible oils. Furthermore, this chapter aims to present EVOO’s suitability for use on Teflon coated pans, which is another common myth.
... Even through filtration and purification, many kinds of toxic and harmful substances in the unqualified edible oils cannot be easily removed. It is more difficult to distinguish unqualified edible oils from the appearance or odor, but this kind of edible oils harm badly to the organism (Moreno et al., 2007). Mixed edible oils are the blended edible oils of two kinds or more than two kinds of pure edible oils in a certain proportion. ...
Article
The advantages of nuclear magnetic resonance (NMR) such as nondestructive and simultaneous detection, high reproducibility and rapidity make it easily develop the objective and credible methods for food analysis and identification. In this study, we developed a computer-aided, MATLAB-scripted expert system which enables NMR data to distinguish different edible oils and evaluate the quality of edible oils. The NMR spectral data of seven species of most popular vegetable edible oils in China were used to establish the assessment criterions including the content percentage of fatty acids and the quality parameters of edible oils. In our case, the identification accuracy of vegetable origin for the pure edible oils is 95.83% and that for the mixed edible oils is 89.58%, and all the recycled waste cooking oils and fried oils were correctly screened out and identified by the expert system. Further, the quality information of the edible oils was also provided. Our results show that the current expert system is a fast, easy-operated and convenient tool for the adulteration identification and quality control of edible oils.
... The effects of cooking on various nutrients (Bongoni et al., 2014;dos Reis et al., 2015b) and certain groups of bioactive phytochemicals (e.g. glucosinolates and polyphenols) (Moreno et al., 2007;Yuan et al., 2009;Zhang and Hamauzu, 2004) in broccoli have been investigated. However, the data of the cooking effects on individual flavonoids remain scarce. ...
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The flavonoid contents in vegetables are strongly influenced by domestic cooking. The objective of this study was to evaluate the effects of domestic cooking on the structurally complex flavonoids in broccoli. Raw broccoli was cooked by boiling, steaming and microwaving. Seven kaempferol (Km) glycosides and one quercetin (Qn) glycoside were identified and quantified in raw and cooked broccoli by HPLC-MS. Boiling resulted in significant loss of all flavonoids, while steaming and microwaving led to minor loses or even increases of the flavonoids. Apparent retention factors (AR) and true retention factors (TR) were calculated for individual flavonoids. AR ranged from 35.6% to 147.5% and TR ranged from 30.4% to 174.1%, respectively, depending on the cooking method and chemical structures of flavonoids. Two different ways to calculate total retention factors, “Retention Factor by Glycoside” and “Retention Factor by Aglycone”, were also calculated. In conclusion, domestic cooking significantly altered the flavonoid contents in broccoli, with cooking method and chemical nature being key influential factors. Acylated Km tri- or tetra-glycosides appeared to be more resistant to domestic cooking.
... In another study, the contents of intact glucosinolates, total phenolics, vitamin C and minerals in fried and edible portions of freshly harvested broccoli were evaluated. It was found in the study that phenolics and vitamin C were more affected than glucosinolates and minerals during frying [36]. ...
... [60] It may also depend on whether the consumed vegetables are cooked/boiled or not, as boiling reduces some of the bioactive phytochemicals. [61] In this study, we found that the prevalence of hypertriglyceridemia and elevated LDL-C was lower in the group with the high consumption of fruits and vegetables. ...
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Aim: This study was designed to evaluate the effects of dietary and lifestyle habits on several blood lipid parameters in the Lebanese population. Methods: This was a cross-sectional study for 2,000 individuals, of whom 1,003 completed the survey about their dietary and lifestyle habits. Anthropometric measurements and blood tests were performed and recorded. Results: Up to 53.2% of the population was hypercholesterolemic. Gender and age contributed to the prevalence of high levels of low density lipoprotein cholesterol (LDL-C) or triglycerides. Prevalence of hypercholesterolemia, hypertriglyceridemia and high LDL-C levels was higher in smokers, physically inactive or those who consume fatty meat or eggs. Prevalence of hypercholesterolemia was not affected by consumption of whole milk, skimmed milk or fruits and vegetables. However, the prevalence of hypertriglyceridemia and high LDL-levels was higher in individuals who consumed whole milk, and lower in those who consumed skimmed or fruits and vegetables. Conclusion: Hyperlipidemia affects more than half of the Lebanese population. The finding that the majority of the individuals were unaware of their lipid profile mandates warrant efforts for both patient and public education.
... In this sense, when comparing different cooking methods, the microwave-cooking caused a 40% reduction of vitamin C content and a 80% reduction of phenolic compounds, as well as boiling, while steaming determines a 11% reduction of phenolic compounds and pressure-cooking a 60% reduction, as well as frying. Boiling and steaming also reduce mineral content in food from 25% to 50% (Moreno, Lòpez-Berenguer, & Garcìa-Viguera, 2007). It can be concluded that phenolic compounds are very sensitive to high temperatures applied during cooking process, as well as exposure to light and oxygen (Longo, Morozova, & Scampicchio, 2017). ...
Article
Acrylamide and phenolic compounds on both fresh and cooked olives were monitored by HPLC/MS-MS and reversed-phase-HPLC methods along different procedures: elaboration process, high hydrostatic pressure (HHP), cooking treatment and bioavailability evaluation. Acrylamide was not detected during the elaboration process and after HHP treatment. Hydroxytyrosol, tyrosol, oleuropein and verbascoside were the most important phenols after HHP treatment. The frying and baking processes on olives enhanced the formation of acrylamide and a significant reduction in the phenolic compounds. The frying process produced lower acrylamide concentration and less reduction of phenolic compounds than the baking process, while in the gastrointestinal digestion these compounds were slightly reduced if compared to the initial stage. As a conclusion, the best way to ingest high quantities of phenols and reduce acrylamide consumption is by ingesting the olives when they are fresh. In case the olives need to be cooked, specific time and temperature conditions shall be applied.
... On the other hand, the highest loss of flavonoids was observed during frying/microwaving (Barakat & Rohn, 2014). Frying and/or microwaving were the most dramatic treatments which cause the leaching of flavonoids into the frying oil, and then a following thermal degradation (Moreno, Lopez-Berenguer, & Garcia-Viguera, 2007;Vallejo, Tomás-Barberán, & Garcia-Viguera, 2003). Interestingly, according to some researchers, total flavonoids increased significantly in the range of 9.5%-410.9% ...
... 13 However, there is much information in the literature about the lack of sulforaphane bioavailability from cooked broccoli and, thus, an expected lack of health benefits. 6,7,16,17 Conditions of the ability of myrosinase to catalyze the formation of sulforaphane within commercially available frozen broccoli were evaluated in Dosz and Jeffery. 18 The optimum pH and temperature at which sulforaphane formation occurs in Brassica oleracea are between 5 and 6 and between 14°C and 25°C, respectively. ...
Article
Sulforaphane is an isothiocyanate occurring in stored form as glucoraphanin in cruciferous vegetables such as cabbage, cauliflower, and kale, and at high levels in broccoli especially in broccoli sprouts. Glucoraphanin requires the plant enzyme myrosinase for converting it into sulforaphane. Sulforaphane is metabolized through mercapturic acid pathway, being conjugated with glutathione and undergoes further biotransformation, yielding metabolites. Sulforaphane is extensively investigated and is in the interest in medicine for its health benefits. It has been shown that sulforaphane may protect against various types of cancer, may also decrease the risk of cardiovascular disease, and help in autism and osteoporosis. Our review offers a short summary of interesting properties of sulforaphane. Both the in vitro and in vivo methods/models and clinical studies are mentioned.
... The use of stir-frying can be also negative in terms of overall losses of glucosinolates (Baenas et al., 2019;Xu, Zhang, et al., 2014;Yuan et al., 2009). Oppositely, other works with broccoli, Brussels sprouts, cauliflower, cabbage, or pakchoi found mild effects of stir-frying (Moreno, López-Berenguer, & García-Viguera, 2007;Nugrahedi, Oliviero, Heising, Dekker, & Verkerk, 2017;Song & Thornalley, 2007). Yuan et al. (2009) suggested that increasing the preheating temperature of oil above 200 C could help in maintaining high levels of glucosinolates, while Nugrahedi et al. (2017) found that the temperature (160 CÀ250 C) and cooking time (1À8 min) did not affect greatly the stability of glucosinolates. ...
Chapter
Glucosinolates are sulfur compounds responsible at least in part of the the characteristic flavor of cruciferous vegetables and condiments. The glucosinolates [and their cognate bioactive forms, the isothiocyanates (ITCs) and indoles] have been studied for decades because of their antimicrobial, anticancer and antiinflammatory bioactivities Eating cruciferous foods is the direct and easiest way for the intake of glucosinolates; it also has the advantage of the coingestion of plant myrosinase enzymes that mediate the hydrolysis of glucosinolates into their bioactive metabolites: ITCs and indoles. However, industrial and cooking processing can negatively affect the stability of glucosinolates and myrosinases. This chapter reviews the effect that conventional processing has on the content of glucosinolates, commonly associated with losses due to thermal degradation. Alternatively, other innovative, nonthermal processing is reviewed as technologies for preserving these compounds and increasing their extractability. Finally, the established methodologies for the extraction and analysis of glucosinolates are discussed, including alternative protocols for assisting such a task.
... Stir-frying experiments were performed at lower temperature (i.e., at 80 and 110-120°C) and the cutting size of the vegetables was larger (florets 40 mm and strips 1 cm) [8,9] than other experiments (i.e., piece of broccoli at 130-140°C and 3 × 3 cm red cabbage at 130°C) [10,11]. In addition, different types of cooking oil were also found to influence to the loss of GS content [23]. Moreover, the loss of total GSs in broccoli by 84% was also reported when deep frying was applied apparently due to the intense thermal degradation [20]. ...
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Stir-frying is a cooking method, originating from Asia, in which food is fried in small amount of very hot oil. Nowadays in many other parts of the world stir-frying is a very popular method to prepare vegetables, because it is fast and fried vegetables are tasty. However, the retention of phytochemicals like the health-beneficial glucosinolates in Brassica vegetables is less explored for stir-frying in comparison to other cooking methods. This study investigates the retention of glucosinolates in Chinese cabbage (Brassica rapa ssp. pekinensis) and pakchoi (Brassica rapa ssp. chinensis) as affected by stir-frying at various cooking durations and temperatures. Stir-frying experiments were performed at set pan temperatures ranging from 160 to 250 °C for a duration of 1 to 8 min. Results showed that aliphatic glucobrassicanapin is the most abundant glucosinolate identified in fresh Chinese cabbage and pakchoi, contributing for 48 and 63% of the total glucosinolate content, respectively, followed by glucoiberin and gluconapin. Stir-frying retains the glucosinolates even at the highest temperature applied. Such retention is explained by the quick inactivation of the glucosinolate-hydrolytic enzyme myrosinase during the first minutes of frying, and by the thermal stability of the glucosinolates at those temperature/time conditions. Moreover, due to the absence of a separate water phase, leaching losses did not occur, in contrast to what is observed when boiling Brassica vegetables. These results show that stir-frying may be a suitable health-beneficial cooking option that prevents the loss of glucosinolates.
Article
Ethnopharmacological relevance: Many wild and cultivated plants are rich in mineral elements and bioactive compounds and are consumed for health purposes. Studies have demonstrated the curative properties of many of these food plants. In this paper, we discuss the properties of several plants with potential health benefits that have previously received little attention. Aim of the study: This review provides an overview and critical discussion of food plants perceived by informants (emic view) as healthy or used as 'food medicine' in Italy. Pharmacological activity of these plants is explored, based upon published scientific research (etic view). Preparation methods, taste perception, toxicity and various potentialities of some food plants are also discussed. Materials and methods: The present review includes literature available from 1877 to 2012. The information was collected from books, scientific papers, and abstracts that reported any plants used as food medicine in Italy. The perceived health properties were analyzed in the framework of recent international phytochemical and phytopharmacological literature. Results: A total of 67 edible wild plants and 18 cultivated vegetables, distributed into 20 families, were reported by informants (in literature). Several plants were highly cited (e.g., Taraxacum officinale Webb., Crepis vesicaria L., Allium cepa L., Allium sativum L.). The most frequent health properties attributed to edible plants by the informants were: laxative (22 species), diuretic (15), digestive (11), galactagogue (8), antitussive (cough) (8), hypotensive (7), tonic (7), sedative (7), hypoglycemic (6). Conclusions: Some edible plants are promising for their potential health properties, such as Crepis vesicaria L., Sanguisorba minor Scop. and Sonchus oleraceus L. Several wild species were perceived by informants to maintain health but have never been studied from a phytochemical or pharmacological point of view: e.g., Asparagus albus L., Crepis leontodontoides All., Hyoseris radiata L. subsp. radiata, Phyteuma spicatum L.
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Recently, trend toward vegetarianism and veganism has globally increased. Effect of domestic cooking methods including microwaving, frying, frying/microwaving, steaming and baking on bioactive compounds of broccoli-based bars (BBBs) was investigated. Total phenolic content (TPC), antioxidant activity and phytochemicals were investigated. Subsequently, identification and quantification of dominant phenolics and glucosinolates were carried out. A sensory evaluation of cooked BBBs was performed, as well. Results indicate that health-promoting compounds in BBBs were significantly affected by cooking methods. Negligible change was found in TPC, whereas antioxidant activity was significantly affected. Cooking treatments except steaming and baking caused significant losses of chlorophylls, carotenoids, and flavonoids in the range of 20-51, 15-58, and 25-33%. Frying and frying/microwaving caused a loss of single phenolic compounds. Total glucosinolates content decreased significantly during frying, frying/microwaving, steaming, and baking, while microwaving did not. The presented data might be helpful for selecting the optimum processing conditions for innovative BBBs.
Article
Brassica vegetables are widely consumed mostly after processing and cooking. These processing and cooking methods not only can affect the taste, texture, flavor and nutrients of these vegetables, but also influence the levels of some important bioactive compounds, such as glucosinolates (GLSs). Glucoraphanin (GLR) is the most abundant GLSs and its hydrolyzed component, sulforaphane (SLR), is the most powerful anti-cancer compound in brassica vegetables. In this review, we find out that varied treatments impact the retention of GLR and the formation of SLR differently. Be specific, 1) freezing can avoid the losses of GLR while short-time microwaving, short-time steaming and fermentation promote the biotransformation from GLR to SLR; 2) Boiling and blanching cause the largest losses of GLR and SLR, while freezing significantly protect their losses.; 3) Stir-frying varies the levels of GLR and SLR in different cooking conditions.
Article
Abstract Phytochemicals content, including several families such as phenolic acids, isoflavones, flavones, flavonols, isothiocyanates, and glucosinolates, was determined in pre-cooked convenience vegetables by ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). It was observed that there is not a common behavior of the individual concentration of phytochemicals during the lifetime and cooking of the matrix, and compounds change their concentration without a specific trend. It was observed that neither lifetime nor cooking process have significant effects on the total content of phytochemicals except in broccoli, although some changes in the individual content of the target compounds were observed, suggesting that interconversion processes could be performed during the lifetime and/or cooking process of the product.
Article
A simple and rapid capillary zone electrophoresis method to quantitatively determine the phenolic acid contents in brassica vegetables is described. Phenolic compounds were extracted from broccoli, broccolini, Brussels sprouts, cabbage and cauliflower and the main hydroxycinnamic acids (sinapic, ferulic, p-coumaric and caffeic acids) were isolated by solid phase extraction with C18 cartridges. Using an optimised method, the four analytes were separated in less than 7min in a 50μm×60cm capillary with a 15mM borate buffer (pH=9.13) and a separation voltage of 30kV at 30°C. A linear relationship was observed for the method (r=0.9997-0.9999) with detection limits ranging from 1.1 to 2.3mg/kg of vegetables for the analytes. This method demonstrated good reproducibility with coefficients of variation of less than 5% for peak area and less than 1% for migration time (n=7). The method was successfully applied to quantitatively determine the phenolic acid contents in a range of brassica vegetables and the results were in good agreement when compared to those from high performance liquid chromatography analysis.
Article
Frying is one of the oldest cooking procedures and is still among the most popular ones for food preparation. Due to their unique sensory characteristics, fried foods are consumed often and with pleasure. During frying, part of the oil is absorbed by the food, thereby becoming part of our diet; most interestingly, in the Mediterranean area approximately 50% of total fat intake is provided by cooking fats. Olive oil is the key lipid component of the Mediterranean diet, the health-promoting effects of which have been largely attributed to olive oil intake. Olive oil is unique among vegetable oils due to its desirable lipid profile and some of its minor components. Scientific evidence now indicates that during frying olive oil behavior is usually equal or superior to that of refined vegetable oils. Herein, an overview of virgin olive oil performance under frying is given, with special reference to the fate of olive oil microconstituents. The compositional changes of foods fried in olive oil are also reviewed and discussed in detail.
Article
Limited research has been conducted on the association between intake of fruits and vegetables and hypertriglyceridemia, especially in Asian populations. This study aimed to investigate the association between total fruit and vegetable intake, as well as subgroups of fruit and vegetable intake, with hypertriglyceridemia among Korean adults. We conducted a cross-sectional study of 7934 adults aged 19-64 years from the fourth Korean Health and Nutrition Examination Survey. Fruit and vegetable intake was estimated from a food frequency questionnaire. Subgroups of fruits and vegetables included citrus, non-citrus and carotene-rich fruits and cruciferous, green leafy and carotene-rich vegetables. Hypertriglyceridemia (plasma triglyceride ⩾150 mg/dl) was diagnosed using a blood sample drawn after 12+ hours of fasting. There were 2001 (25.2%) cases of hypertriglyceridemia among the participants. Total fruit intake was significantly inversely associated with the prevalence of hypertriglyceridemia; the multivariate odds ratios (95% confidence intervals) of hypertriglyceridemia across increasing quintiles were 1.00 (ref), 0.76 (0.62, 0.92), 0.72 (0.58, 0.90), 0.68 (0.54, 0.85) and 0.64 (0.49, 0.82; Ptrend=0.001) after controlling for survey year, body mass index, waist circumference, smoking, alcohol drinking, physical activity, education and income. Similar inverse associations were found for all fruit subgroups. However, we found no significant association between intakes of total or subgroups of vegetable and hypertriglyceridemia; the odds ratio for top vs bottom quintile was 1.00 (0.81-1.24) for total vegetable intake. Our findings support a potential beneficial role of fruit consumption to reduce blood triglyceride levels in Asian populations.European Journal of Clinical Nutrition advance online publication, 27 May 2015; doi:10.1038/ejcn.2015.77.
Numerous epidemiological studies indicate that broccoli protects human being against cancer. It is rich source of antioxidant materials specially flavonoids and vitamin C. In the present investigation, a reversed-phase high-performance liquid chromatographic procedure with UV detection at 245 nm has been developed and validated for the determination of vitamin C in broccoli. The freeze-dried tissues were extracted with mixture of acetic acid, meta-phosphoric acid, sulfuric acid and EDTA. Samples were centrifuged at 12000 rpm for 20 min at 4°C and 20 μl of this extract injected directly into the HPLC system. The HPLC system consisted of Lichrocart column C 8 (250x4.6 mm, 5 μm) and a gradient mode of potassium dihydrogen phosphate 50 mM : methanol which was kept at a flow rate of 0.5 ml/min. The method was validated for selectivity, linearity (r 2>0.999), intra-day precision (≤ 2.7), inter-day precision (≤ 3.0) and accuracy measured by determination of recovery (96-106%). The LOD and LOQ were found 3.0 and 10.1 μg/ml, respectively. Because of speed and accuracy, it may be the UV-HPLC choice for analysis of vitamin C in Brassica oleracea L. var. italica Plenck.
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The aim of this study was to assess the effect of some foods consumed previous to an erosive beverage on dental enamel and cement. The study was performed on 40 human teeth unaffected, extracted for orthodontic braces. The teeth were cut to obtain 80 cervical slices including enamel and dentine/cement areas. The slices were randomly divided in four groups. The 20 samples of control group (group 1) were submitted in 72 hours to nine demineralisation cycles (3 cycles/24 hours) by immersion in Pepsi-Cola ® for 5 min (32 mL/ sample). The samples from other three groups were immersed in cheese extract (group 2), broccoli extract (group 3) and undilluted cow milk (group 4) for 5 min (32 mL/sample) previous to Pepsi-Cola ® immersion. For each group, microhardness was measured using digital device CV 400 DAT on 10 samples and surface roughness was determined on another 10 samples by profilometric method using profilometer Taylor Hobson- Surtronic 25. For each sample mean value of Vicker hardness (VH) and mean value of roughness (Ra) were calculated as a result of 5 determinations. In enamel/cement areas the mean value Ra recorded for group 1 was 3,83/3,5 times higher than mean value Ra in study group 4, 2,99/2,95 times higher than mean value Ra in study group 3 and 2,81/3,04 times higher than mean value Ra in study group 2. The mean values of VH of enamel/cement before and after immersion in the tested food varied from 389/68 VH to 235/34 VH in group 4, from 367/64 VH to 354/58 VH in group1, from 382/69 VH to 371/61 VH in group 2 and from 393/63 VH to 381/57 VH for group 3. The consumption of foods like milk, cheese and broccoli before the ingestion of erosive beverages can significantly reduce the erosion of dental enamel and cement.
Article
Glucosinolates (GSLs, β-D-thioglucoside-N-hydroxysulfates) are polar compounds present in varying amounts in members of the Brassicaceae family. They suppress soil-borne pests due to the biofumigant properties of the highly toxic isothiocyanates present in Brassica vegetables. The objectives of this investigation were to: (1) assess variation in GSLs concentrations among collard plants grown under three soil management practices: sewage sludge (SS) mixed with native soil, chicken manure (CM) mixed with native soil, and no-mulch (NM) native soil, (2) quantify GSLs concentrations in collard roots, leaves, and stems at harvest for potential use of their crude extracts in plant protection, and (3) assess myrosinase activity in soil amended with CM and SS mixed with native soil. Separation of GSLs was accomplished by adsorption on a DEAE-Sephadex ion exchange resin using disposable pipette tips filled with DEAE, a weak base, with a net positive charge when ionized and exchange anions such as GSLs (hydrophilic plant secondary metabolites). Quantification of total GSLs was based on inactivation of collard endogenous myrosinase and liberation of the glucose moiety from the GSLs molecule by addition of standardized myrosinase and colorimetric determination of the liberated glucose moiety. Across all treatments, SS and CM increased soil organic matter content from 2.2% in native soil to 4.2 and 6.5%, respectively. GSLs concentrations were significantly greater in collard leaves (30.9 µmoles g(-1) fresh weight) compared to roots and stems (7.8 and 1.2 µmoles g(-1) fresh weight), respectively. Leaves of collard grown in soil amended with SS contained the greatest concentrations of GSLs compared to leaves of plants grown in CM and NM treatments. Accordingly, leaves of collard plants grown in soil amended with SS could play a significant role in sustainable agriculture as alternative tools for soil-borne disease management in conventional and organic agriculture.
Chapter
Epidemiological studies indicate that regular consumption of fruits and vegetables may reduce the risks of many degenerative diseases like cancer, cardiovascular disease, cataract etc. This is attributed mainly to the intake of dietary polyphenols. They are the most abundant antioxidants in our diet. Polyphenols exhibit a wide range of pharmacological and medicinal properties, including anti-inflammatory, anticarcinogenic, vasodilatory actions, which have been mostly attributed to their free radical scavenging, metal chelating, and antioxidant activities. Data of vegetable composition are usually determined on raw material; however, for nutritional purposes it should be considered that most of them are cooked in different ways before consumption. These cooking processes would bring about a number of changes in the physical characteristics, chemical composition of vegetables and may have an influence on the bioavailability of polyphenols and indirectly on human health. Therefore, the present chapter reviewed the effects of different cooking methods on antioxidant activity, phenolics and other phytochemicals content in most common vegetables.
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Ayurveda stresses the important role of food in maintaining health and preventing disease. Healthy, natural, wholesome food is considered to be essential for nourishing body, mind, and soul. In Ayurveda, health centers on nutritious food, and a good digestion depends upon our lifestyle. Our lifestyle depends on our environment, and our environment affects the quality of our food, which in turn affects the quality of our health. But our modern environment is radically different from that of the previous thousands of years, and we are not well educated about how our environment impacts our food, particularly in terms of freezing, microwaving, and processing with chemical additives. Ayurveda proposes that food is best eaten when it is lightly cooked or steamed. Cold food and drinks should be avoided, as should food that is microwaved, frozen, or highly processed. In addition, various food combinations or practices should be avoided such as consuming equal portions of honey and ghee or the heating of honey. But is there any biomedical evidence for these practices? This chapter will evaluate evidence-based research as it applies to Ayurvedic dietary recommendations and discuss how it relates to modern food processing and food consumption. © 2014 Springer Science+Business Media New York. All rights reserved.
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Food is necessary for all human beings for survival. It consists of carbohydrates, proteins and fats. It provides energy, satiety and building blocks needed for synthesis and maintaining structural integrity of biological membranes. Eventhough earlier there was awareness on the importance of bioactive compounds such as vitamins present in foods for preventing deficiencies, only in recent times an increased attention is being given to phytonutrients for their numerous health benefits. These bioactive compounds are also termed as phytoceuticals, and nutraceuticals. Hippocrates (460 -377 BC) the father of medicine recommended “Let thy food be thy medicine and thy medicine be thy food”. This concept reflected on the importance of dietary components for preventive and therapeutic effects on diseases. Epidemiological and laboratory studies have given ample evidences for the role of phytonutrients in healthy ageing and longevity. Good nutrition helps to ensure a healthy and proper functioning of the body. In addition, recent research suggests that many of the phytochemicals found in plant foods may be helpful in reducing risk factors associated with life style diseases. Epidemiological studies on the relationship between dietary habits and disease risk have shown that food has a direct impact on health. It is generally accepted that plant derived foods with fruits, nuts, vegetables, grains, legumes, spices exert beneficial effects on human health and slowing down of age-related diseases. Some of the benefits derived from phytonutrients are summarized in Table 1. The structures of bioactive molecules identified from different plant sources responsible for health benefits are shown in Fig 1. As the longetivity of human population is increasing, the chronic age-related diseases such as cardiovascular diseases, neurodegenerative diseases, diabetes and several types of cancer are also increasing. There is a need to increase in the intake of plant derived food in order to improve our health status and to delay the development of diseases. In this phytonutrients as nutraceuticals has an important role to play. In general, following the dietary guideline to “Eat a Variety of Foods”- particularly plant-derived foods will have a positive impact on health.
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The formation of health‐beneficial isothiocyanates (ITCs) from glucosinolates depends on a wide variety of plant‐intrinsic factors (e.g., concentration of glucosinolates, activity of myrosinase and specifier proteins) and on a multitude of extrinsic post‐harvest factors such as the conditions used during industrial processing, domestic preparation, mastication and digestion. All of these factors contribute to a large variability in the formation of ITCs (and other breakdown products), as well as their intake and absorption upon consumption of Brassica vegetables. This uncertainty in ITC intake and absorption is a barrier for the determination of an optimal Brassica vegetable consumption pattern. In this review, the intrinsic and extrinsic factors that affect the formation, intake and absorption of ITCs are described according to the most recent findings. The focus of this review includes the hydrolysis reaction mechanisms, the elucidation of the primary factors that play a role in the hydrolysis reaction, the influence of processing and cooking conditions, the effect of chewing, and the roles of the gastric and upper intestinal phases, including the effect of the meal composition (e.g., the effect of other meal compounds present during digestion) on the potential formation of ITCs. This article is protected by copyright. All rights reserved
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Effects of microwave and conventional cooking methods were studied on total phenolics and antioxidant activity of pepper, squash, green beans, peas, leek, broccoli and spinach. Total phenolics content of fresh vegetables ranged from 183.2 to 1344.7 mg/100 g (as gallic acid equivalent) on dry weight basis. Total antioxidant activity ranged from 12.2% to 78.2%. With the exception of spinach, cooking affected total phenolics content significantly (p < 0.05). The effect of various cooking methods on total phenolics was significant (p < 0.05) only for pepper, peas and broccoli. After cooking, total antioxidant activity increased or remained unchanged depending on the type of vegetable but not type of cooking.
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Frying is one of the oldest methods of food preparation. It improves the sensory quality of food by formation of aroma compounds, attractive colour, crust and texture. Undesirable changes involved are loss of nutritive quality e.g. due to degradation of heat - susceptible vitamins. The influence of common frying methods (frying in an oven, in a pan deep frying) on cooking time and nutritive value of vegetables, potatoes, meat, poultry and fish is described and compared to other cooking methods (boiling, steaming, stewing). Frying of vegetables, potatoes and breaded meat, poultry and fish, no matter whether in a pan or by deep - frying, is associated with fat uptake (2 - 14 g per 100 g of raw food) while non - breaded high fat food of animal origin loses fat during frying (2 - 30%). Data suggest that the fat quantity absorbed during frying increases up to a saturation limit which depends on the kind of food and on the amount of panade. Deep - fried meat, poultry and fish usually absorb less fat than meat, poultry and fish fried in a pan. The kind of fat had no essential influence on fat uptake. After frying of vegetable food and of breaded meat, poultry and fish, the content of protein, carbohydrates and minerals was nearly fully retained while boiling and steaming reduced the mineral content by 25-50%. In the majority of cases frying including deep frying also retained the vitamins B1, B2, B6 and C better than boiling, steaming and stewing.
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Evidence indicates that cruciferous vegetables are protective against a range of cancers with glucosinolates and their breakdown products considered the biologically active constituents. To date, epidemiological studies have not investigated the intakes of these constituents due to a lack of food composition databases. The aim of the present study was to develop a database for the glucosinolate content of cruciferous vegetables that can be used to quantify dietary exposure for use in epidemiological studies of diet-disease relationships. Published food composition data sources for the glucosinolate content of cruciferous vegetables were identified and assessed for data quality using established criteria. Adequate data for the total glucosinolate content were available from eighteen published studies providing 140 estimates for forty-two items. The highest glucosinolate values were for cress (389 mg/100 g) while the lowest values were for Pe-tsai chinese cabbage (20 mg/100 g). There is considerable variation in the values reported for the same vegetable by different studies, with a median difference between the minimum and maximum values of 5.8-fold. Limited analysis of cooked cruciferous vegetables has been conducted; however, the available data show that average losses during cooking are approximately 36 %. This is the first attempt to collate the available literature on the glucosinolate content of cruciferous vegetables. These data will allow quantification of intakes of the glucosinolates, which can be used in epidemiological studies to investigate the role of cruciferous vegetables in cancer aetiology and prevention.
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Seeds, of either commercial crucifer crops or some wild and weed relatives, were screened for intact glucosinolates using a previously developed ion-pair LC-MS method. This method, in contrast to GC-MS techniques, ensures the accurate measurement of all classes of glucosinolates. Many crucifer seeds contained very high concentrations of glucosinolates with low concentrations of additional pigments and secondary metabolites. The other common seed metabolites were cinnamoylcholine esters, for example, sinapine. Glucosinolates derived from homologues of l-methionine were characteristic of Brassica and related crucifer species. In addition, significant concentrations of 4-hydroxy-3-indolylmethylglucosinolate were found in the majority of Brassica species. Wild and weed species often had relatively simple glucosinolate profiles: either a single glucosinolate or a predominant glucosinolate together with trace amounts of others. Species identified with seed glucosinolate profiles suitable for purification included various Alyssum, Erysimum, and Iberis species for 3-methythiopropyl-glucosinolate and 3-methylsulfinylpropyl-glucosinolate and various Alyssum, Erysimum, and Lepidium species with very high concentrations of C4-C6 aliphatic glucosinolates. Seeds of Arabis, Barbarea, Lepidium, Moringa, and Sinapis species were good sources of aromatic glucosinolates, and Azima tetracantha was a good source for N-methoxy-3-indolylmethyl-glucosinolate. MS data are reported for all of the intact glucosinolates detected from the screening process.
Article
The physiological responses encountered when Brassica vegetables are fed to animals are due to the activities of the hydrolysis products of glucosinolates (GS). More than one hundred GS are distributed in plants, primarily amongst the members of the Cruciferae. Attention has been focused on the ability of GS breakdown products to induce a specific set of bio-transformation enzymes in various experimental animals. The beneficial effects of GS breakdown products include anticarcinogenic properties especially in human cervical and endometrial cancer cells, mouse mammary tumorigenesis, human prostate cancer, hormone-related cancers, rainbow trout hepatocarcinogenesis, and human lung cancer. The enhanced antioxidant activity for protection against reactive oxygen species at the cellular level is another important biochemical effect. Growth depression, poor palatability, decreased food efficiency, hypertrophy and hyperplasia of the thyroid, goitre, liver lesions and necrosis occur when the diet is highly rich in GS products. Some of the GS have been associated with hepatotoxicity, neurological effects, tumor promotion and epithelial hyperplasia either in rats or rabbits. Hence, its intrinsic toxicity and potential as tumor promoter restrict any development in therapeutic applications. This review describes the plethora of effects caused by GS derivatives, both beneficial and adverse on experimental animals.
Article
Total aliphatic, indolic and aromatic glucosinolates were evaluated in the edible portions of fresh harvested inflorescences of five commercial and three experimental broccoli (Brassica oleracea L var italica) cultivars grown under various climatic and agronomic conditions, ie early (winter) or late (spring) season with poor (15 kg ha-1) or rich (150 kg ha-1) sulphur fertilisation, in an attempt to identify differences due to genetic and agronomic factors. The predominant glucosinolates in all broccoli cultivars were 4-methylsulphinylbutyl-glucosinolate (glucoraphanin), 3-indolylmethyl-glucosinolate (glucobrassicin) and 1-methoxy-3-indolylmethyl-glucosinolate (neoglucobrassicin). The results showed no significance differences in total glucosinolates between rich and poor fertilisation, whereas total glucosinolates were detected more significantly in the late than in the early season. All broccoli cultivars showed a higher content of indolic glucosinolates than aliphatic glucosinolates. Clear advantages were detected in the analysed commercial cultivars, as the experimental cultivars yielded lower concentrations of these compounds.© 2003 Society of Chemical Industry
Article
Sensory characteristics and retention of vitamin C, vitamin B6, calcium, and magnesium were determined in vegetables cooked by conventional and microwave methods. Fresh broccoli, cauliflower, and potatoes and frozen corn and peas were cooked by boiling, steaming, microwave boiling and microwave steaming to equivalent tenderness as measured by a shear press. The sensory analysis of the vegetables cooked by the four methods indicated that some differences existed in color, flavor, texture, and moistness of the vegetables. No one method resulted in vegetables with optimum sensory characteristics. The nutrient retention was highest in foods cooked by microwave steaming, followed by microwave boiling, followed by steaming, and then by boiling. Generally vegetables cooked by microwave techniques retained higher percentages of the U. S. Recommended Daily Allowances for the nutrients than those cooked by conventional methods.
Article
Total flavonoid and individual hydroxycinnamoyl derivative (sinapic and caffeoyl-quinic acid derivative) contents were evaluated in the edible portions of freshly harvested broccoli (cv Marathon inflorescences) before and after cooking and in the cooking water. High-pressure boiling, low-pressure boiling (conventional), steaming and microwaving were the four domestic cooking processes used in this work. The predominant sinapic acid derivatives were identified as 1,2,2′-trisinapoylgentiobiose and 1,2′-disinapoyl-2-feruloylgentiobiose. In addition 1,2-diferuloylgentiobiose and 1-sinapoyl-2,2′-diferuloylgentiobiose were also identified in broccoli inflorescences. The results showed large differences among the four treatments in their influence on flavonoid and hydroxycinnamoyl derivative contents in broccoli. Clear disadvantages were detected when broccoli was microwaved, namely high losses of flavonoids (97%), sinapic acid derivatives (74%) and caffeoyl-quinic acid derivatives (87%). Conventional boiling led to a significant loss of flavonoids (66%) from fresh raw broccoli, while high-pressure boiling caused considerable leaching (47%) of caffeoyl-quinic acid derivatives into the cooking water. On the other hand, steaming had minimal effects, in terms of loss, on both flavonoid and hydroxycinnamoyl derivative contents. Therefore we can conclude that a greater quantity of phenolic compounds will be provided by consumption of steamed broccoli as compared with broccoli prepared by other cooking processes. Copyright © 2003 Society of Chemical Industry
Article
Flavonoids, hydroxycinnamoyl derivatives (sinapic and ferulic acid derivatives+caffeoyl-quinic acid derivatives) and vitamin C were quantified by HPLC-MS in five commercial and three experimental cultivars from freshly harvested broccoli inflorescences ( Brassica oleracea L. var. italica). In order to identify differences due to genetic and agronomic factors, the broccoli cultivars were grown under different climatic and agronomic conditions, i.e. early (winter) and late (spring) seasons with poor (15 kg/ha) and rich (150 kg/ha) sulphur fertilisation. The predominant sinapic and ferulic acid derivatives in all broccoli cultivars were 1,2-diferuloylgentiobiose, 1,2,2'-trisinapoylgentiobiose and 1,2'-disinapoyl-2-feruloylgentiobiose. In addition, the compounds 1,2-diferuloylgentiobiose, 1-sinapoyl-2,2'-diferuloylgentiobiose and 1,2,2'-triferuloylgentiobiose were identified in broccoli inflorescences for the first time. Extreme agronomic and environmental conditions (late season and rich sulphur fertilisation which could induce different stress situations on the plant) enhanced the phenolic content. Thus, total flavonoids showed the highest content, followed by total sinapic and feruloyl acid derivatives and total caffeoyl-quinic acid derivatives. In general, cultivars grown under rich fertilisation and late season conditions showed higher vitamin C content than those grown under the poor and early ones. Finally, results showed that commercial cultivars rendered higher amounts of phenolic compounds and vitamin C than the experimental ones.
Article
Total aliphatic and indole/aromatic glucosinolates and vitamin C content (ascorbic+dehydroascorbic acid) were evaluated in the edible portions of fresh harvested broccoli (Brassica oleracea L. var. italica) florets (Marathon cv.) before and after cooking and in the cooking water. High pressure boiling, steam cooking, microwaving and low pressure boiling (conventional) were the four domestic cooking processes used in this work. Results showed great differences among the four cooking processes and their influence on the content of glucosinolates and vitamin C. Thus, clear disadvantages were detected when cooking in a microwave due to the high loss of vitamin C (40%) and total glucosinolates (74%) in comparison with the rest of treatments. High pressure and conventional boiling had a significant loss rate of total glucosinolates (33% and 55% respectively) regarding fresh raw broccoli, due to the leaching into the cooking water. On the other hand, steaming had minimal effects on glucosinolates and vitamin C. Therefore, we can conclude that a large quantity of glucosinolates and vitamin C will be consumed in steamed broccoli when compared to the other cooking processes.
Article
The potential of 24 green leafy vegetables (GLV) in cooked form was assessed for the contents of eight micronutrients; bioavailability of iron, zinc and copper; and for proximate principles. The bioavailable densities of iron, zinc and copper (1.3±1.2, 1.1±0.5, 0.7±0.3 mg/1000 kcal) in individual GLV and GLV-based meals were higher than those in meals based on cereals or legumes. Average bioavailable iron density in particular, was 3.6 times higher (P<0.01) than the average value for composite cereal–legume-based meals indicating GLV as promising fortificants of iron for vegetarians. Contents per 100 g cooked weight of beta-carotene (80–5920 μg), ascorbic acid (2.2–58.2 mg), folic acid (35.6–185 μg), riboflavin (0.03–0.08 mg) and thiamin (0.04–0.46 mg) were found to show large variability among different GLV but the average levels of beta-carotene and ascorbic acid were significantly higher than the other food classes (P<0.05). The contents of the vitamins were compared in cereal–legume meals (12), cereal–fruit vegetable meals (16), and cereal–GLV meals (30) in another experiment. The results indicate a highly significant and 8.7-13.1-fold rise in beta-carotene levels, and a 1.7–2.3-fold rise in the levels of folic acid and riboflavin in GLV meals as compared to other meals indicating the potential for increasing these three vitamin levels using GLV.
Article
Antioxidant components, including phenolics, ascorbic acid and carotenoids, of broccoli floret and stem, antioxidant activity, and their changes during conventional and microwave cooking, were investigated. Broccoli florets and stem were cooked by conventional boiling or by microwave over up to 300 s. Total phenolics were retained by up to 28.1–28.4% in the cooked florets and 55.6–57.8% in the cooked stems, and ascorbic acid by 34.1–34.4% and 29.1–29.5%, respectively. Total carotenoids were retained better compared to total phenolics and ascorbic acid. Total antioxidant activity was retained at 34.7–35.0% in the cooked florets and 34.6–34.7% in the cooked stems and phenolic antioxidant activity was retained at 37.4% and 64.7%, respectively. The results showed that antioxidant components and antioxidant activity in broccoli were lost heavily during the cooking. These losses need to be taken into account when calculating the dietary intake of these compounds from the cooked broccoli.
Article
Broccoli (Brassica oleracea L var italica Plenck) was used as a testing material and Sampled in four groups, including fresh, precooked (50 °C, 10 min), cooked (boiling, 8 min), and precooked followed by cooking (precooked + cooked), to investigate the effect of the cooking treatment on the textural change in the vegetable. After freeze-drying and extraction by the use of methanol, the antioxidant properties of the extracts from the four groups were estimated and compared with those of α-tocopherol and butylated hydroxyanisole (BHA). The antioxidant properties include reducing power, ferrous ion chelating power, α,α-diphenyl-β-picrylhydrazyl (DPPH) radical-scavenging activity and inhibitory effect against lipid peroxidation. The data indicated that, after cooking in boiling water for 8 min, the broccoli tissue had a 51% relative peak force of the fresh tissue, whereas the tissue, after precooking at 50 °C for 10 min, and the tissue, after precooking + cooking, had relative peak forces of 172% and 119%, respectively, of the fresh tissue. These results revealed that cooked tissue with precooking softens more slowly than that without precooking; that is, precooked tissue can show a higher resistance to softening during cooking. The extracts from the precooked, cooked, and precooked + cooked broccoli exhibited high reducing powers. At a sample-to-solvent (mg/ml) ratio of 20 mg/ml, these extracts had 1.5 ∼ 1.7 times as high reducing powers as those of α-tocopherol and BHA. These four extracts showed high ferrous ion chelating power, and the extracts from fresh and precooked broccoli had the highest, namely 90.5% at a sample-to-solvent ratio of 2 mg/ml. These extracts also exhibited high DPPH radical-scavenging activity, at 96.8, 97.3, 98.6 and 97.9%, respectively, for the fresh, precooked, cooked, and precooked + cooked samples, at a sample-to-solvent ratio of 20 mg/ml. The four extracts exhibited lower inhibitory effects against the peroxidation of a linoleic acid emulsion system than did α-tocopherol and BHA.
Article
Thermal degradation of individual glucosinolates within the plant matrix was studied. Red cabbage samples were heated at different temperatures for various times. To rule out the influence of enzymatic breakdown and to focus entirely on the thermal degradation of glucosinolates, myrosinase was inactivated prior to the thermal treatments. All identified glucosinolates degradation when heated at temperatures above 100 °C. The indole glucosinolates 4-hydroxy-glucobrassicin and 4-methoxyglucobrassicin showed the highest degree of showed degradation, even at temperatures below 100 °C.Kinetic parameters have been estimated for the degradation that could be described by first-order kinetics. At temperatures below 110 °C indole glucosinolates have a significant higher degradation rate constant as compared to aliphatic glucosinolates. The breakdown of 4-hydroxyglucobrassicin seems to consist of two parallel reaction pathways. Based on the proposed degradation kinetics and the estimated parameters, the degree of thermal degradation of all individual glucosinolates at standardized heating conditions (blanching, cooking and canning) was simulated. Glucosinolates are expected to be not very susceptible to thermal degradation during blanching conditions. Cooking will cause more thermal degradation to indole glucosinolates (38%) as compared to aliphatic glucosinolates (8%). Canning, the most severe heat treatment, will result in significant thermal degradation (73%) of the total amount of glucosinolates.
Article
Nitrite and nitrate levels in broccolis coming from different cultures from the south of Navarra (Spain) were analyzed. Fresh products had only traces of nitrites and low levels of nitrates (48–97 ppm KNO3). Industrial freezing gave rise to an increase in the nitrate levels (127–232 ppm KNO3), probably as a consequence of high levels in the processing water. Cooking decreased nitrate levels (between 22 and 79%), there being no differences in the levels of reduction between fresh and frozen vegetables. Nitrite levels were scarcely affected either by freezing or by cooking.
Article
A study was made of the antioxidant content, activity and colour of two New Zealand commercially grown tomatoes (Lycopersicon esculentum L. var. Excell and Aranca) cultivated in glasshouses using hydroponic techniques. Excell tomatoes were harvested and stored individually while cultivar Aranca was harvested by cutting the vine, which consisted of a group of eight tomatoes. Both cultivars of tomatoes were stored in the dark for 4 days at 15°C to simulate normal pre-purchase storing conditions. The antioxidant content of the raw tomatoes after 4 days of storage were markedly different while the CIE LAB colour values of the cut inner surfaces of the two cultivars were similar. After 4 days storage, subsamples of each cultivar were either boiled, baked or fried, and analysis of CIE colour, ascorbic acid, total phenolics, lycopene and antioxidant activity (using the ABTS assay) was undertaken. Boiling and baking had a relatively small effect on the ascorbic, total phenolic, lycopene and antioxidant activity of the two cultivars while frying significantly reduced (P<0.001) the ascorbic, total phenolic and lycopene contents of the two cultivars. Chromatic colour analysis showed that both cultivars became significantly (P<0.001) darker and less red after cooking by all methods.
In this study the effect of sous vide processing, steaming and traditional boiling of broccoli florets on retention of ascorbic acid, vitamin B6 and folacin was investigated. Freshly prepared samples were also sensorily evaluated. In all heat treatments ascorbic acid was found to have the highest retention, and was therefore judged not to be suitable as an indicator for vitamin retention in general. When the three types of heat treatment were compared, boiling showed lowest retention of all the vitamins examined (45-64% in 5 min), whereas sous-vide processing gave the highest retentions (97-100% in 5 min). Retentions during steaming were a little lower (83-100% in 5 min). Sensory evaluation showed that sous-vide cooked and steamed broccoli florets generally had higher acceptability than boiled.
Article
Proximate composition, mineral content and the effect of traditional processing practices on the retention of ascorbic acid, riboflavin and thiamine were studied using amaranth, cowpea, peanut, pumpkin and sweetpotato leaves. Results of this study indicated that, crude protein, crude fat, carbohydrate and ash contents were in the range of 20.64--46.56 percent, 2.57--4.34 percent, 35.43--63.50 percent and 8.92--15.69 percent respectively. The mineral content per 100 g of fresh vegetables was in the range of 83.64--229.34 mg, 145.97--780.19 mg, 11.5--2l.31 mg, 43.02--110.30 mg, 0.96--5.90 mg and 0.40--2.24 mg for Ca, K, Na, Mg, Fe and Zn respectively. For ascorbic acid, riboflavin and thiamine, concentrations in 100 g of fresh vegetables were in the range of 43.78--89.00 mg, 0.62--1.71 mg and 0.09--0.30 mg respectively. The traditional processing practices of sun/shade drying and storing in ventilated containers resulted in a significant (P <0.05) decrease in ascorbic acid, riboflavin and thiamine for all vegetables. Conventional blanching and cooking for up to 15 minutes resulted in a significant (P <0.05) increase in riboflavin content in cowpea, peanut and pumpkin greens while in amaranth and sweetpotato leaves, thermal processing resulted in a significant (P <0.05) decrease in the vitamin. Based on the results of this study, the vegetables were good dietary sources of minerals, carbohydrate and protein.
Article
Food processing has the potential to alter the nutrient quality of foods. This review deals with the effects of home-based cooking and storage practices on the micronutrient content of foods. It describes the effects of cooking, freezing and refrigeration on the vitamin and mineral content of meats, fish, fruit, vegetables and cereals. Based on this review, we suggest that the consumer should be aware of the possibility that losses in nutritional quality of foods may result from an improper use of cooking and storage techniques available at home.
Article
Total and individual levels of glucosinolates (GSs) were measured in red cabbage after various microwave treatments varying in time and intensity of the treatments. Furthermore, the myrosinase enzyme activity of the microwave-heated vegetables was determined. The retention of GSs in the cabbage and the residual activity of the hydrolytic enzyme as a result of microwave preparation were compared with untreated cabbage. In general, high total GS levels were observed for all of the applied microwave treatments. Strikingly, many of the time/energy input combinations resulted in levels exceeding the total GS content of the untreated cabbage material. Moreover, the increase in levels seems to be associated with the energy input applied. A possible explanation for this behavior is an increased extractability of GS from heat-treated cabbage as compared to raw cabbage. Substantial myrosinase activity was retained in cabbage treated at low (24 min, 180 W) and intermediate microwave powers (8 min, 540 W) while microwave cooking for 4.8 min at 900 W (259.2 kJ energy input) resulted in a complete loss of hydrolytic activity. In this respect, differences in observed temperature profiles of the various microwave treatments play an important role. Higher retention of GSs and controllable amounts of active myrosinase can offer increasing health-promoting properties of microwave-prepared Brassica vegetables.
Article
People's diet offers a greater and more diverse group of plant bioactives than do drugs, and they often do not realise that many drugs are derived from the compounds originally discovered in plant foods. Numerous epidemiological studies indicate that Brassica vegetables in general, and broccoli in particular, protect humans against cancer since they are rich sources of glucosinolates as well as possessing a high content of flavonoids, vitamins and mineral nutrients. One unusual phytotherapeutic role of broccoli is for skin diseases--the juice of the leaves is used to treat warts. However, the main use of broccoli stems from its health-promoting properties. Some criteria have been proposed to evaluate the possibilities of developing new "functional foods" to reduce the risk of specific cancers; largely in broccoli, which is associated with cancer protection. Processing conditions, transport, domestic cooking, etc., affect the health-promoting properties of broccoli and these have been widely studied. This review makes an in-depth study of the chemical and biological characterization of the phytochemicals of broccoli and the effects on the bioactive composition of broccoli.
Article
Changes in phenolic compounds, total glucosinolates, and vitamin C were monitored during the productive period along five inflorescence development stages of three broccoli commercial cultivars (Marathon, Monterrey, and Vencedor). In an attempt to identify differences due to agronomic factors, broccoli cultivars were grown under different sulfur fertilization with poor (15 kg/ha) and rich (150 kg/ha) rates. Phenolic compounds and vitamin C concentrations showed, in all broccoli cultivars, a rising trend from the first stage until the over-maturity stage, both for rich and poor sulfur fertilization. Significant differences were detected in the first two stages between rich and poor sulfur fertilization in total glucosinolates for all broccoli cultivars, where the highest concentration was always observed in the second development stage (used as minimally processed product) during poor fertilization. With regard to the last three stages, the glucosinolate concentration in the poor sulfur fertilization started to slope down until the over-maturity stage. Where rich sulfur fertilization is concerned, the highest level was reached during the third stage (used as minimally processed product also), and after that, glucosinolate concentration decreased until the fifth stage.
Article
In cabbage, glucosinolates such as sinigrin are hydrolyzed by plant myrosinase to allyl isothiocyanate (AITC), allyl cyanide, and, in the presence of an epithiospecifier protein, 1-cyano-2,3-epithiopropane (CEP). Isothiocyanates have been implicated in the cancer-protective effects of Brassica vegetables. The effect of processing on the hydrolysis of glucosinolates was investigated in cabbage. Cabbage was steamed or microwaved for six time durations over 7 min. Glucosinolate concentrations were slightly reduced after microwave cooking (P < 0.001) but were not influenced after steaming (P < 0.05). Myrosinase activity was effectively lost after 2 min of microwave cooking and after 7 min of steaming. Hydrolysis of residual glucosinolates following cooking yielded predominantly CEP at short cooking durations and AITC at longer durations until myrosinase activity was lost. Lightly cooked cabbage produced the highest yield of AITC on hydrolysis in vitro, suggesting that cooking Brassica vegetables for a relatively short duration may be desirable from a health perspective.
Recommended intakes for vitamins and minerals Wellness foods A to Z: an indispensable guide for health-conscious food lovers
  • S Margen
Margen S. 2002. Recommended intakes for vitamins and minerals. In: UC Berkely Wellness Letter, editors. Wellness foods A to Z: an indispensable guide for health-conscious food lovers. New York: REBUS Inc. p 88–9.
Wellness foods A to Z: an indispensable guide for healthconscious food lovers
  • S Margen
Margen S. 2002. Recommended intakes for vitamins and minerals. In: UC Berkely Wellness Letter, editors. Wellness foods A to Z: an indispensable guide for healthconscious food lovers. New York: REBUS Inc. p 88-9.