Novel varieties of broccoli for optimal bioactive components under saline stress

BACKGROUND: Consumption of broccoli is increasing steadily worldwide because of the interest in its bioactive composition and nutritive value for health promotion. Novel broccoli cultivars to be established under current adverse conditions in production areas (aggressive environmental conditions and saline irrigation waters) need to maintain physical and nutritional quality for consumption and year‐round supply to the markets. The newly introduced cultivars ‘Naxos’ and ‘Parthenon’ have been selected as potential candidates to replace the currently underperforming ‘Nubia’ variety. We aimed to compare the physical and phytochemical quality (glucosinolates, hydroxycinnamic acids, flavonoids, vitamin C and minerals), as well as the in vitro antioxidant capacity of these three cultivars under conditions of environmental stress. RESULTS: ‘Parthenon’ showed equal productivity and nutritional composition to ‘Nubia’, whereas ‘Naxos’ presented in general the best results when compared to ‘Nubia’ and ‘Parthenon’. For phenolic compounds ‘Nubia’ presented the highest contents, although ‘Naxos’ seemed better adapted to saline stress conditions, as suggested by the lowest degree of variation in the contents of healthy phytochemicals, including phenolic compounds, when grown under such conditions. CONCLUSION: ‘Naxos’ broccoli performed best and is a suitable candidate to replace ‘Nubia’ for marketable, nutritive and phytochemical quality, especially in areas of production under adverse conditions as found in Mediterranean southeast Spain (semiarid climate with saline irrigation water). Copyright © 2011 Society of Chemical Industry     

Phenolic compound contents in edible parts of broccoli inflorescences after domestic cooking

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     

Improving the phytochemical composition of broccoli sprouts by elicitation

In order to increase the concentrations of bioactive compounds in broccoli sprouts, exogenous elicitors: methionine, tryptophan, chitosan, salicylic acid (SA) and methyl jasmonate (MeJA) were sprayed at different concentrations during germination. The effects of the elicitors on vitamin C, phenolic compounds and glucosinolate levels were assessed in 3, 5 and 7-days old seedlings. The application of 200, 300 μM SA and 0.01% chitosan induced increases, by 26%, 18% and 54%, respectively in the content of vitamin C in 5 days old broccoli sprouts. Flavonoid concentration was also increased by 31% and 33% after 10 μM MeJA and 100 μM SA treatments, respectively in 7 days old broccoli sprouts. In contrast, methionine or tryptophan solutions did not positively affect the vitamin C or the phenolic compounds in the sprouts. The individual classes of glucosinolates respond differently to the elicitor treatment. Methionine, a sulphur-containing amino acid, applied at 5 mM, significantly increased, by 32%, the levels of aliphatic glucosinolates. However, indole glucosinolates presented a significant response to the induction with tryptophan, SA or MeJA treatments. Tryptophan at 10 mM concentration augmented by 1.8-fold the indole glucosinolate concentration in 7 days old broccoli sprouts, and the treatments of 100 μM SA and 25 μM MeJA also induced significantly higher amounts of indole glucosinolates (by 33% and 51%, respectively) in 7 days old treated broccoli sprouts. Therefore, the application of elicitors could be a useful tool for improving the bioactive metabolites in broccoli sprouts for fresh consumption or functional ingredients for nutraceuticals foods.     

Effect of domestic cooking on the red cabbage hydrophilic antioxidants

The contents of vitamin C, total phenolics, anthocyanins, hydroxybenzoic and hydroxycinnamic acids as well as 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) monocation radical scavenging activity were evaluated in two varieties of red cabbage before and after conventional and steam‐cooking. During the conventional cooking 32.7–64.5% of vitamin C and 45.7–66.9% of total phenolics were retained in cooked tissue. Decreasing cooking water volume by half led to better retention of both phenolics (by 2.7–14.5%) and vitamin C (by 14.2–18.4%). However, shortening the cooking time by half affected the retention of phenolics and vitamin C only by 3.8–6.7% and 0–2.2%, respectively. Steam‐cooking is recommended to prevent the major loss of scavenging activity, because under these conditions, the corresponding TEAC (Trolox Equivalent Antioxidant Capacity) values were reduced only by 5–20%. Moreover, the content of vitamin C was decreased by 2.1–22.7% while losses of total phenolics were up to 10%. The phenolics are the major source of free radical scavenging activity of red cabbage, since the contribution of vitamin C to TEAC for fresh and cooked red cabbage was from 18.2 to 28.5%.     

Influence of light on health‐promoting phytochemicals of broccoli sprouts

BACKGROUND: Broccoli (Brassicaceae) is a rich source of phytochemicals (glucosinolates and phenolic compounds) and micronutrients (vitamins and minerals). Germinated broccoli sprouts contain much higher levels (10–100 times) of aliphatic (glucoraphanin) and indolic glucosinolates than the inflorescences. This quality characteristic of broccoli sprouts plays an important role in human health and disease prevention. Although it is known that genetic and environmental factors can affect the composition of broccoli inflorescences, the influence of such factors on the seeds and sprouts has not been widely reported. Therefore the aim of this study was to determine the effect of light versus dark growth conditions on the phytochemical composition (vitamin C, phenolic compounds and glucosinolates) of broccoli sprouts. RESULTS: Broccoli sprouts grown in the light were found to have much higher concentrations of vitamin C (by 83%), glucosinolates (by 33%) and phenolic compounds (by 61%) than those grown in the dark. During a 7 day period there was a clear and analogous trend in both treatments, with a general reduction in concentrations over time. Among the different organs studied (seeds, cotyledons, stems and roots), the cotyledons contained the highest levels of bioactive compounds, while the roots contained the lowest. CONCLUSION: Light treatment of sprouting broccoli seeds increased their concentration of health‐promoting phytochemicals, mainly during the first 3–5 days of development. Therefore the younger broccoli sprouts are a better source of bioactive compounds for the consumer than the inflorescences. Copyright © 2008 Society of Chemical Industry     

Basis for the new challenges of growing broccoli for health in hydroponics

BACKGROUND: Variations in the contents of phytochemicals with biological activity in broccoli could originate as a result of genetic and environmental factors. An understanding of the effects of growth conditions on the bioactive compounds in broccoli is essential for improving its quality and nutritive value. Using salinity (40 mmol L^?1 NaCl), and foliar sprayed compounds (methionine, tryptophan and chitosan) as different stress conditions, broccoli developed in soilless culture in the greenhouse was analysed for biologically active phytochemicals (glucosinolates, caffeoyl‐quinic, ferulic and sinapic derivatives and vitamin C). RESULTS: The application of elicitors during head formation could be beneficial for the enrichment in phytochemicals in broccoli. Management practices for increasing a given phytochemical (e.g., glucoraphanin or glucobrassicin) may be related to a decreased level of natural antioxidants (hydroxycinnamic acids). Growing broccoli hydroponically in the greenhouse in winter (Mediterranean climate) needs the supporting treatment of abiotic stress during development (i.e., NaCl, elicitors). CONCLUSION: The use of hydroponic growth conditions for broccoli and the application of stress factors (elicitors) at head induction and during development may serve the purpose of enhancing its nutritional quality to deliver a health‐promoting food. Copyright © 2008 Society of Chemical Industry     

Potential bioactive compounds in health promotion from broccoli cultivars grown in Spain

Glucosinolates, phenolic compounds and vitamin C were evaluated in two commercial and 12 experimental cultivars of broccoli (Brassica oleracea L var italica) grown under uniform cultural conditions. The predominant glucosinolates in all broccoli cultivars were 4‐methylsulphinylbutyl glucosinolate (glucoraphanin) and 3‐indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates such as 4‐OH‐glucobrassicin and N‐methoxyglucobrassicin were detected in lower amounts. The total glucosinolate concentration ranged from 3.0 µmol g^?1 dw (dry weight) in Pentathlon (experimental cultivar) to 28.3 µmol g^?1 dw in I‐9905 (experimental cultivar). Flavonoids, caffeic acid derivatives and sinapic acid derivatives were quantified in methanol extracts. The largest content of flavonoids was found in the commercial cultivars Marathon and Lord, around 60 mg kg^?1 fw (fresh weight). The vitamin C content of broccoli ranged from 43.1 mg per 100 g fw in Lord (commercial cultivar) to 146.3 mg per 100 g fw in SG‐4515 (experimental cultivar). © 2002 Society of Chemical Industry     

Genotypic effects on the phytochemical quality of seeds and sprouts from commercial broccoli cultivars

Determining ontogenic diversity in vegetables, in general or Brassicas in particular, regarding the bioactive content, is an interesting task since the most promising Brassicaceae foods could have the highest nutritional and health-promoting properties. Therefore, vitamin C, phenolic compounds, glucosinolate content, and total antioxidant capacity were evaluated in commercial cultivars of broccoli (Brassica oleracea var. italica; cv. Nubia, cv. Marathon and cv. Viola) seeds and during the sprouting period. Vitamin C was not detected in dormant seeds and its content increased with the germination, reaching values ranging from 53 (cv. Nubia) to 64 (cv. Marathon) mg/100 g FW, at the end of the monitored period (14days). The total glucosinolate content in seeds and 3-day-old sprouts was higher in cv. Marathon (1005 and 556 mg/100 g FW, respectively), however cv. Viola sprouts registered the highest glucosinolate content 7 and 14 days after sowing (235 and 208 mg/100 g FW, respectively). Aliphatic glucosinolates were more affected by genetic factors than the indolic glucosinolates, being glucoraphanin the predominant glucosinolate in cv. Nubia and cv. Marathon, whereas glucoiberin was the major glucosinolate in cv. Viola. The flavonoid and total phenolic content was significantly higher in cv. Viola. Also, seeds of this cultivar showed the highest antioxidant capacity (2.7 mg Trolox/g FW).     

Relationship between free amino acids and glucosinolates in primary and secondary inflorescences of 11 broccoli (Brassica oleracea L var italica) cultivars grown in early and late seasons

Amino acids have been identified as the precursors of a class of secondary plant metabolites, the glucosinolates, but there is no report on the relationship between the two in vivo. In this work we have investigated the relationship between free amino acids and glucosinolates in 11 broccoli cultivars grown in early (April–July) and late (August–January) seasons. Free amino acids and glucosinolates were quantified by HPLC in primary and secondary inflorescences at maturity stage. Analysis of the data revealed that no significant correlation exists between free amino acids and glucosinolates, suggesting that the precursors of these compounds might be used during the first step of the biosynthetic process to form intermediates, the aldoximes and thiohydroximates, which will then be used in the second stage of the biosynthesis to form, apart from glucosinolates, other secondary plant metabolites. © 2001 Society of Chemical Industry     

Relationship of climate and genotype to seasonal variation in the glucosinolate–myrosinase system. II. Myrosinase activity in ten cultivars of Brassica oleracea grown in fall and spring seasons

Myrosinase catalyzes the hydrolysis of glucosinolates found in the Brassicaceae, generating a variety of bioactive reaction products that may aid in the prevention of some cancers and that are suppressive to soil‐borne plant pathogens. Two cultivars each of broccoli (Brassica oleracea L var italica), Brussels sprouts (B oleracea var gemmifera), cabbage (B oleracea var capitata), cauliflower (B oleracea var botrytis), and kale (B oleracea var acephala) were grown during two fall seasons and two spring seasons to determine if myrosinase activity varied by season. Regression models that included mean temperature and photosynthetic photon flux (PPF) during the growing seasons showed that climatic variables explained seasonal differences for myrosinase activity. Activity‐FW (FW = fresh weight; U g^?1) and specific activity (U mg^?1) were significantly (p ≤ 0.05) affected by season, botanical group and group × season. Activity‐FW had a negative linear relationship with temperature, and a positive linear but negative quadratic relationship with PPF. Specific activity had a positive linear and a negative quadratic relationship with both temperature and PPF. Therefore the influence of climatic factors on myrosinase activity in Brassica species may affect the potential benefits of the glucosinolate–myrosinase system. Copyright © 2004 Society of Chemical Industry     

Effect of post‐harvest treatments on the level of glucosinolates in broccoli

Broccoli is a very perishable vegetable with a high water content (around 88%) which leads to rapid dehydration and probably to an alteration in composition if conditions after harvest are not controlled. This study evaluates the glucosinolate pattern and glucosinolate levels in the principal and secondary inflorescences of fresh broccoli cv ‘Tokyodome’, and after being submitted to some situations which are likely to occur during or after harvest: room temperature (±20 °C) for 5 days, kept in the fridge at 4 °C for 5 days, and frozen after blanching. Another set of material was harvested 5 days later, simulating a post‐maturation stage, and analysed. The highest total glucosinolate content was found at commercial maturation with 20 888 and 20 355 µmoles kg⁻¹ DW in the principal and secondary inflorescences, respectively. Keeping the inflorescences at room temperature caused the most significant (P < 0.05) reductions in total and individual glucosinolates, except for 4‐hydroxyindol‐3‐ylmethyl‐, 2‐hydroxy‐2‐phenylethyl‐ and 2‐phenylethyl‐, when compared to the other situations. The highest levels (10 925 µmoles kg⁻¹ DW) of 4‐methylsulphinylbutyl‐, the precursor of the anti‐cancer isothiocyanate sulphoraphane, were found in the inflorescences freshly harvested at commercial stage. Refrigeration at 4 °C and freezing were shown to be the best preservation processes for maintaining high levels of these and other glucosinolates in contrast with the other situations. © 1999 Society of Chemical Industry     

不同食用植物油中维生素E组分及含量研究

通过对9个不同品种的138个食用植物油样品中维生素E组分及含量的测定,分析研究不同食用植物油中维生素E组分及含量的分布情况。结果表明:9个油脂品种、101个一级油样品中维生素E含量范围为5.9~1 246.6 mg/kg,平均值652.4 mg/kg,维生素E总量的平均值排序为大豆油棉籽油玉米油葵花籽油菜籽油米糠油花生油芝麻油山茶油;不同油脂样品中维生素E的组分有明显差别,米糠油含有最齐全的8种维生素E组分,并且生育三烯酚含量的平均值占维生素E总量平均值的44.2%;玉米油含有3种生育酚和2种生育三烯酚,棉籽油中含有3种生育酚和1种生育三烯酚,但这两种油脂中生育三烯酚含量平均值分别仅占维生素E总量平均值的5.8%和2.8%;大豆油、菜籽油、花生油、葵花籽油均含有α-、γ-、δ-生育酚3种组分;山茶油中含有α-、γ-生育酚2种组分;芝麻油仅含有γ-生育酚1种组分。除芝麻油之外,所有油脂中均含有α-生育酚和γ-生育酚,其中葵花籽油中α-生育酚含量最高,大豆油中γ-生育酚含量最高。同一油脂品种、不同等级的油脂中维生素E含量也存在差异,总体趋势是维生素E含量随油脂精炼程度的加深而降低,但个别二级菜籽油样品中维生素E含量低于一级菜籽油,这与所采集油脂样品的来源不同有关。不同油脂品种、不同等级的食用植物油中维生素E组分及含量因油料品种、油脂精炼工艺的不同显示出明显差异。     

不同烹调和贮藏方式对番茄中V_C含量的影响

采用2,6二氯酚靛酚法来测定番茄中VC含量,研究不同家庭烹调方法和贮藏方式对VC的影响,旨在为促进烹调工艺标准化提供相关理论依据。结果表明:随着烹调时间增加,番茄中VC含量越来越少,说明其损失程度越来越大。炒制番茄比煮制番茄更易于保持番茄中维生素C。烹调时加入食醋,有利于保护番茄中VC。加醋炒制3min的番茄最适于食用。烹调后番茄中VC含量与贮藏时间成反比,0℃保藏比25℃保藏更有利于保护VC,贮藏时间24h后食用价值较低。      

不同食用油对番茄红素抗氧化活性的影响

目前市面上有多种品牌的番茄红素软胶囊,使用的食用油介质不同。为了更好地指导生产和消费,选择亚麻籽油、花生油、大豆油、玉米油和葵花籽油五种不同种类的食用油和番茄红素混合,采用五种体外抗氧化活性的测定方法来研究这几种不同的食用油对番茄红素抗氧化活性的影响。实验结果显示,几种食用油对番茄红素的抗氧化性都有很好的促进作用,其中亚麻籽油、花生油的效果最为显著,但是亚麻籽油在质量浓度高于40 μg/mL时,促进效果可能会下降。     

基于HPLC-Q-TOF-MS技术鉴定不同品种花椰菜叶中硫代葡萄糖苷

研究了2种硫代葡萄糖苷标准品质谱裂解规律,发现硫代葡萄糖苷的β-D-硫代葡糖、磺酸肟及来源于氨基酸侧链R上的键都能够断裂发生重排现象从而形成碎片离子。在质谱裂解规律的基础上对3种不同品种的花椰菜叶中硫代葡萄糖苷进行结构鉴定。鉴定结果表明,3种花椰菜叶中含有8种硫代葡萄糖苷,包括3-(甲基亚磺酰基)丙基硫代葡萄糖苷(1)、4-(甲基亚磺酰)丁基硫代葡萄糖苷(2)、3-丁烯基硫代葡萄糖苷(3)、4-羟基苄基硫代葡萄糖苷(4)、1-羟基-吲哚-3-亚甲基硫代葡萄糖苷(5)、3-吲哚甲基硫代葡萄糖苷(6)、1-含氧甲基吲哚-3-亚甲基硫代葡萄糖苷(7)、6-(甲基磺酰)己基硫代葡萄糖苷(8)。其中,宝塔花椰菜叶中含有4种硫代葡萄糖苷(1,2,4,5),青花菜叶中含有6种硫代葡萄糖苷(2,3,5,6,7,8),紫色花椰菜叶中含有7种硫代葡萄糖苷(1,2,4,5,6,7)。     

Effects of Production and Processing Factors on Major Fruit and Vegetable Antioxidants

ABSTRACT: Public awareness of the purported health benefits of dietary antioxidants has increased the demand for fruit and vegetable products with recognized and improved antioxidant quality and has created new opportunities for the horticulture and food industry to improve fruit and vegetable quality by enhancing antioxidant content. This review describes the production and processing factors that influence the content of the major fruit and vegetable antioxidants, namely vitamin C, carotenoids, and phenolics. There is substantial genetic variation in the content of each of these antioxidant types among fruit and vegetable cultivars. Compared with vitamin C and carotenoids, the levels of phenolic antioxidants appear to be more sensitive to environmental conditions both before and after harvest. Although vitamin C can be readily lost during fresh storage, the content of certain carotenoids and phenolics can actually increase during suitable conditions of fresh storage. Vitamin C and phenolics are more susceptible to loss during processing, especially by leaching from plant tissues into processing water. The combination of cultivar variation and responsiveness to specific environmental conditions can create opportunities for the production and processing of fruits and vegetables with improved antioxidant properties.