Enzymatische Bestimmung des Gesamtglucosinolat-Gehaltes in FutterrapsBrassica napus L.var. napus

Zusammenfassung Für die Bestimmung des Gesamtglucosinolat-Gehaltes in Futterraps wurde eine enzymatische Methode ausgearbeitet, die auf folgenden Analysenschritten beruht: Der Inaktivierung pflanzeneigener Enzyme, der Extraktion der zu bestimmenden Glucosinolate, der enzymatischen Zerstörung freier Glucose, der Hydrolyse der Glucosinolate durch Myrosinase und der enzymatischen quantitativen Erfassung nicht oxidierter freier sowie von Glucosinolaten stammender Glucose.In 23 Sorten von Rapspflanzen wurden 0,95 bis 1,96% Glucosinolate in der Trockensubstanz gefunden mit einer mittleren prozentualen Abweichung der Einzelwerte vom Mittelwert von 2,9. Zur Beurteilung von Futterraps ist es mit diesem Verfahren möglich, neben dem Ertrag und der Krankheitsresistenz auch den Gehalt an Glucosinolaten, die sowohl Tierfutter als auch Eier, Milch und Fleisch indirekt beeinträchtigen, mit heranzuziehen.

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Enzymatic determination of the total content of glucosinolates in the rape plantBrassica napus L.var. napus

Summary A method for the quantitative determination of the total content of glucosinolates in rape plants used as green forage was worked out. The analysis includes the following steps: Inactivation of the native plant enzymes, extraction of the glucosinolates to be determined, enzymatic oxidation of the free glucose, hydrolysis of the glucosinolates by myrosinase and enzymatic quantitative analysis of the unoxidized free glucose and finally the one originating from glucosinolates. In 23 rape varieties the glucosinolate content ranges from 0.95 to 1.96% of dry matter. The average deviation for single determinations from the mean amounts to 2.9%. With this procedure a selection of rape varieties for green forage is possible not only based on their yield and disease resistence but also on their content of glucosinolates which influence negatively the forage as well as indirectly eggs, milk and meat.

     

Variation of glucosinolates in three edible parts of Chinese kale (Brassica alboglabra Bailey) varieties

Glucosinolates in Chinese kale (Brassica alboglabra Bailey) were analysed by liquid chromatography–mass spectrometry (LC–MS), and the variation of glucosinolates in three edible parts (sprout, rosette leaf and bolting stem) of 27 Chinese kale varieties was investigated. Thirteen glucosinolates, including eight aliphatic glucosinolates, four indole glucosinolates and one aromatic glucosinolate, were identified in Chinese kale. The contents of total glucosinolate varied extensively among the different edible parts, and the total glucosinolate contents in the sprouts were obviously higher than those in rosette leaves and bolting stems. Obvious differences in the total and individual glucosinolate contents were also observed in each edible part among the different varieties. Gluconapin was the most abundant glucosinolate among all the edible parts of the 27 varieties except for the sprout of JL-26. The JL-26, JL-25 and JL-16 varieties are good candidates for future breeding programs since they contain high levels of methylsulphinylalkyl glucosinolates (glucoiberin and glucoraphanin) in certain edible parts.     

Glucosinolate content of Brassica vegetables-Chinese cabbages Pe-tsai (Brassica pekinensis) and Pak-choi (Brassica chinensis)

The glucosinolate content of 19 cultivars of pe-tsai and three cultivars of pak-choi Chinese cabbage (Brassica pekinensis Lour) Rupr and (Brassica chinensis L, respectively) has been determined using high performance liquid chromatography. The levels of total glucosinolates were 0.097-0.337 g kg^?1 fresh weight (mean 0.198) in pe-tsai and 0.39-0.704 g kg^?1 (mean 0.534) in pak-choi. The main components present were (2-hydroxybut-3-enyl-progoitrin), but-3-enyl- (gluconapin), 5-methylsulphinylpentyl- (glucoalyssin) and pent-4-enyl (glucobrassicanapin) glucosinolates, respectively. In comparison with other UK brassicas and American cultivars of Chinese cabbage, both the UK-grown pak-choi and pe-tsai are low in glucosinolates.     

Changes in Glucosinolate Concentrations in BrassicaCrops (BoleraceaandBnapus) Throughout Growing Seasons

In the Iberian Peninsula, Brassica crops are grown throughout the year and may be consumed at immature stages or leaves may be harvested by ‘picking-over’ during plant growth. Consumption of Brassicas in Portugal is high but there is no information on the levels of glucosinolates in such material. Changes in the total and individual glucosinolate concentrations of four Brassica oleracea types (two cultivars of Portuguese cabbage, one Portuguese kale type and one hybrid white cabbage) and one Portuguese Brassica napus type were monitored throughout two growing seasons, spring/summer (SS) and summer/winter (SW). Glucosinolates were determined between sowing and maturity corresponding to nine sampling dates in the leaves and five harvests in the heads. The main glucosinolates in B oleracea types were 3-methylsulphinylpropyl-, allyl- and indol-3-ylmethyl- whereas in the B napus type pent-4-enyl-, 2-hydroxybut-3-enyl- and but-3-enylglucosinolate predominated. In the leaves of B oleracea types, the highest concentration of total glucosinolates and of most of the individual glucosinolates was observed at 14 days after sowing whilst, in the heads the highest levels were noted at the start of head formation. In the B napus , the highest total and individual glucosinolate concentration was generally observed at the end of the growing season. Both for the total and for the main individual glucosinolates there were significant differences ( P< 0·001) between the nine harvest dates and between growing seasons. Between the two seasons, the glucosinolate levels in SS were generally higher than in SW. A comparison of cultivars showed the hybrid cabbage to have generally higher glucosinolate levels than the Portuguese types, except for B napus .     

Glucosinolates in brassica vegetables. Analysis of 22 varieties of brussels sprout (Brassica oleracea var. gemmifera)

The glucosinolate content of 22 cultivars of Brussels sprout have been determined. The levels of total glucosinolates, determined by methods based on glucose release and gas chromatography, were substantially higher than those reported by other workers for cabbage and Chinese cabbage. The major glucosinolates in Brussels sprout leaf material were identified as gluconapin, progoitrin, sinigrin and glucobrassicin, with the latter two generally predominating. Detailed analysis of the material from five different growing sites has shown considerable variation in the total content but surprisingly little difference in the relative proportions of the individual glucosinolates within each cultivar. The glucosinolates of the corresponding seed material differ significantly from that in leaf; in particular glucobrassicin is found in trace amounts only, and glucoerucin, glucotropaeolin and neoglucobrassicin are all present, in addition to sinigrin, progoitrin and gluconapin.     

The effect of cooking and processing on the glucosinolate content: Studies on four varieties of portuguese cabbage and hybrid white cabbage

The concentrations of individual and total glucosinolates were measured in four types of Portuguese cabbage and in one hybrid white cabbage before and after cooking. Typical Portuguese culinary procedures include boiling the cabbage for 10 min but for particular kale types the leaves are first shredded then boiled for 5 min (Caldo verde). Analysis of the fresh cabbage, cooked leaves and cooking water showed that the glucosinolate content of the cabbages is reduced by more than 50%. Almost all of this loss is accounted for as intact glucosinolates in the cooking water, normally used for soups in Portugal.     

云南不同品种大叶种茶树生化成分季节变化特征分析

探讨品种及季节对云南大叶种茶树生化成分的影响,为茶树种植品种及茶叶加工采摘季节的选择提供一定理论依据.采用云南大叶种云抗10号、云抗14号、雪芽100号、佛香2号和紫娟共5个品种为供试材料,在春、夏和秋三季,分别取其新梢的一芽二叶进行蒸青固样,分析不同季节5个茶树品种主要生化成分(水分、水浸出物、茶多酚、儿茶素组分、氨...     

Glucosinolates in isaño (Tropaeolum tuberosum) tubers: qualitative and quantitative content and changes after maturity

Six varieties of isaño (Tropaeolum tuberosum), an Andean edible tuber, were analysed. The aim was to characterise qualitatively and quantitatively their content of glucosinolates and to determine concentration changes of these compounds upon delayed harvest. Additionally, exploratory assays were carried out on the effect of postharvest cold storage of the tubers as well as of a drying process imposed on blanched tuber slices. Only one glucosinolate (p‐methoxybenzyl glucosinolate) was found in the six domestic varieties analysed. Its concentration varied between 36.5 and 90.0 µmol g^?1 dry matter. This range is relatively high when compared with other edible glucosinolate‐containing vegetables. ‘Dark’ coloured tuber varieties showed higher levels than ‘light’ coloured tuber varieties at normal harvest time. Of the two varieties on which the effect of delayed harvest was studied, one showed increasing and then decreasing changes until 44 days after maturity, while the other did not show any significant change with time. Postharvest cold stored samples showed similar changes to tubers kept in soil, and glucosinolate levels in dried blanched tubers did not differ significantly from those in fresh samples. Taken together, the data indicate that the glucosinolate content of isaño is highly dependent on both the variety and the time of harvest. These parameters should be taken into account when considering isaño as a promising food source with medicinal properties for humans and animals, but also with possible adverse biological effects, all related to the presence of glucosinolates. Copyright © 2004 Society of Chemical Industry     

Influence of blanching and freezing broccoli (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">italica</Emphasis>) prior to storage and cooking on glucosinolate concentrations and myrosinase activity

Glucosinolates contribute to the chemoprotective effects of Brassica vegetables. The influence of blanching and freezing broccoli, followed by storage or cooking, on its glucosinolate concentration and myrosinase activity was investigated. Myrosinase activity was reduced by 93%, while glucosinolate concentration was unaltered after blanch-freezing broccoli. Blanch-frozen Brassica retained the glucosinolate content of its fresh counterpart after storage at T = −20 °C for up to 90 days. Fresh or blanch-frozen broccoli was stir-fried, boiled, boiled and kept hot for 2 h, or left uncooked. Stir-frying retained the highest glucosinolate concentration and myrosinase activity, regardless of pre-cooking. Boiling and keeping blanch-frozen broccoli hot completely denatured myrosinase and decreased glucosinolate concentration by 42%. Aromatic and indole glucosinolates were reduced to a larger extent than aliphatic glucosinolates, especially when boiled broccoli was kept hot. The final concentration of glucosinolates in Brassica is influenced by cooking, while the myrosinase activity is modified by pre-treatment and subsequent cooking.     

Variation of glucosinolates in 62 varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) and their antioxidant activity

Glucosinolate (GSL) and antioxidant activity in 62 varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) were determined by HPLC and DPPH, HRSA, and FRAP assays. Five aliphatic GSLs: progoitrin, sinigrin, glucoalyssin, gluconapin, and glucobrassicanapin; four indolyl GSLs: 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin; one aromatic GSL: gluconasturtiin were identified. Glucobrassicanapin and gluconapin documented the most abundant (average 4.52 and 3.72 μmol/g DW, respectively). The contents of total GSLs varied extensively among 62 varieties (range from 2.83 to 48.53 μmol/g DW). Comprehensive differences in total and individual GSL contents have also been observed among different varieties. Indolyl and aromatic GSL together accounted 26% of the total GSLs; but there are few differences among varieties. FC7 and FI17 could be good candidates for future breeding programs since they had a high quantity of glucobrassicin (2.10 and 1.66 μmol/g DW, respectively). Most of the Chinese cabbage varieties showed significant antioxidant activities when compare with positive control. However, three antioxidant assays were not significantly correlated with total GSLs. The presence of significant quantities of glucobrassicin in some varieties should be studied more extensively, since GSL is the precursor of indole-3-carbinol, a potent anticancer isothiocyanate.     

Glucosinolate profiles of international rapeseed lines (Brassica napus and Brassica campestris)

Seed samples from a range of international rapeseed lines (Brassica napus L and B campestris L) were analysed for glucosinolate content using high performance liquid chromatography (HPLC). This analytical method provided a total profile consisting of eight different glucosinolates, including those used to define the Canola standard. The data indicated that broad categories of distinct glucosinolate profiles existed among the seed lines analysed. Indole glucosinolate content, expressed as a percentage of total glucosinolate content, was higher in the low glucosinolate lines of B napus. The actual contents of all eight glucosinolates in the seed were variable, particularly gluconapin, glucobrassicanapin and progoitrin. The importance of this HPLC procedure in facilitating selection for high or low contents of individual glucosinolates is discussed.     

Glucosinolates in seed of rape and turnip rape as affected by variety and environment

Seed meals of winter and summer types of varieties of Brassica napus and B. campestris, grown at different localities and in different years, have been analysed for content of glucosinolates which produce oxazolidinethiones and volatile isothiocyanates upon enzymic hydrolysis. Considerable differences existed in amounts of glucosinolates between species and between winter and summer types of the same species. Varietal differences were relatively small in most of the material studied. Samples of the Polish summer rape variety Bronowski and selections from this variety, however, exhibited very low glucosinolate contents; this is probably genetically determined. Environmental variation generally amounted to ±15% of the average value. Under certain environments, however, 65% lower values than average were obtained. Lack of sulphur in the growth medium of soil-free cultures resulted in seeds low in glucosinolates. In practical farming low glucosinolate content has been found in rape seed as a result of low sulphate content in the soil.     

硒硫互作对白菜芽苗菜硫代葡萄糖苷含量及抗氧化性的影响

为探讨硒硫互作对白菜芽苗菜硫代葡萄糖苷(以下简称硫苷)含量及抗氧化性的影响,以白菜种子为实验材料,通过4 mmol/L ZnSO₄溶液单独喷施、50μmol/L和100μmol/L的Na₂Se O₃溶液单独喷施以及二者联合喷施,分析白菜芽苗菜主要生理生化指标、抗氧化能力及硫苷含量等变化规律。结果表明,单独施用Zn SO₄溶液对白菜芽苗菜造成了生长胁迫,而单独施用Na₂Se O₃溶液可增加芽长和单株平均质量;Na₂SeO₃溶液联合ZnSO₄溶液喷施处理可以有效缓解单独施用ZnSO₄溶液对白菜芽苗菜生长发育的抑制作用。同时,相较于对照(喷施去离子水),经过ZnSO₄溶液联合Na₂SeO₃溶液喷施处理后,白菜芽苗菜硒元素含量及总硫苷含量均显著提高(P<0.05),其中ZnSO₄溶液联...     

Effect of nitrogen and sulfur fertilization on glucosinolates in the leaves and roots of broccoli sprouts (Brassica oleracea var. italica)

Broccoli (Brassica oleracea L. var. italica cv. Marathon) sprouts are a rich source of glucosinolates, particularly 4‐methylsulfinylbutyl glucosinolate (glucoraphanin), the precursor of the chemoprotective isothiocyanate, sulforaphane. Sulfur and nitrogen fertilization have been shown to influence the pattern and levels of glucosinolates in mature broccoli, but little information is available on the fertilization of sprouts, a transient stage of broccoli growth, which have been recommended for salads. Therefore, an experiment was set up to evaluate the effect of N and S fertilization on the glucosinolate content of the aerial part and roots of broccoli sprouts. Nitrogen was tested at 0, 45.5, 91.0 mg L^?1 and sulfur at 0, 14.6 and 29.2 mg L^?1. The results showed that total glucosinolates in the aerial part were significantly higher (P < 0.001) than in the roots. The major glucosinolates in the aerial part were 4‐methylsulfinylbutyl and 3‐methylsulfinylpropyl whereas in the roots they were 2‐phenylethyl and 4‐methylthiobutyl. Fertilization of broccoli sprouts had a significant (P < 0.001) detrimental effect on the levels of aliphatic glucosinolates whereas the opposite was noted for indole and aromatic glucosinolates, for some of the fertilization combinations tested. Overall, the results indicate that broccoli sprouts do not benefit from fertilization. Copyright © 2006 Society of Chemical Industry     

Effect of harvest date and pod position on glucosinolates in oilseed rape (Brassica napus)

Pod samples from four varieties of winter oilseed rape (Brassica napus L) were taken twice weekly from 26 to 3 days before harvest from upper, middle and lower third portions of the main raceme. Seeds were analysed for individual glucosinolate concentration by HPLC. Total glucosinolate content increased suddenly during the sampling period. The timing of the increase depended on variety but occurred before harvest would have been practical. Proportions of individual glucosinolates in Rafal, the only “high” glucosinolate variety examined, did not change over the sampling period. In the other varieties, the proportion of 2-hydroxy-but-3-enyl (progoitrin) increased and the proportion of 2-hydroxy-pent-4-enyl decreased as sampling progressed, so that the concentration of individual glucosinolates could not be predicted from total glucosinolate content. The ‘low’ glucosinolate varieties contained a significantly smaller concentration of progoitrin and summed aromatic glucosinolates than Rafal. Variations in glucosinolate content with pod position were smaller than those due to sampling date, but there was a greater concentration of glucosinolates in seeds from pods lower on the terminal raceme. The results would indicate that care should be taken if seed samples from the plant are taken.     

Fate of Singrin in Methanol/Ammonia/Water-Hexane Extraction of B. juncea Mustard Seed

The individual glucosinolates present in B. juncea mustard seed were determined. Sinigrin (allyl glucosinolate) was the major glucosinolate of mustard seed and constituted 92.9% of the total glucosinolates. The effect of CH₃OH/NH₃/H₂O-hexane treatment on the concentration of glucosinolates was studied. Over 97% of sinigrin originally present in the seed was removed by the above solvent extraction system, mainly in the intact form. Breakdown products of sinigrin were quantified in the treated meal, in the extracted oil and in the polar phase (gums). Aglycon products were allyl cyanide, allyl isothiocyanate and 2,3-epithiopropane cyanide. Sugar breakdown products were glucose, thioglucose, thioglucose dimer and furfuryl alcohol. Desulfosinigrin was a minor decomposition product and might have acted as an intermediate in the decomposition of sinigrin.     

ALTERATION OF GLUCOSINOLATE CONTENT, PATTERN, AND MUTAGENICITY OF CABBAGE (BRASSICA OLERACEA) GROWN ON MUNICIPAL SEWAGE SLUDGE—AMENDED SOIL

Cabbage (Brassica oleracea var. capitata) was grown on soil (control) or municipal sewage sludge-treated plots. The cabbage was freeze-dried and analyzed for glucosinolate content and pattern. Results showed that cabbage grown on sludge-amended soil contained only half the glucosinolate content of cabbage grown on the control plot. The pattern of individual glucosinolates present was also altered. The sludge-grown cabbage glucosinolate extract was shown to be mutagenic in the non-activated test system of S. typhimurium TA 100. Extracts of both sludge-grown and control cabbage were shown to enhance the mutagenicity on a dose-response basis of aflatoxin B₁, benzo(a)pyrene, and captan.     

Comparison of HPLC and GLC methodologies for determination of glucosinolates using reference material

 The reference material rapeseed of known glucosinolate composition, was analysed by HPLC and GLC and two commercially available glucosinolates (glucotropaeolin and sinigrin) were used as internal standards. The HPLC method enabled determination of 11 different glucosinolates (as desulphoglucosinolates) that occur in the rapeseed. Only seven glucosinolates (as trimethylsilylated desulphoglucosinolates) were separated by GLC. The latter method did not allow the determination of methylsulphinylalkyl glucosinolates (glucoiberin, glucoraphanin and glucoallysin) and did not separate optical isomers of 2-hydroxy-3-butenyl glucosinolate (progoitrin and epi-progoitrin). Statistical evaluation of data (t-test, F-test) revealed no significant differences between the tested methods at the 95% confidence level. The advantages and disadvantages of both widely used chromatographic methods are discussed. Received: 26 May 1997 / Revised version: 11 July 1997