Correction for protein content in the determination of the glucosinolate content of rapeseed by the X-RF method

Thirty six rapeseed samples from a factorial designed nitrogen and sulphur trial were analysed for total glucosinolate content by the X-ray fluorescence (X-RF) and HPLC methods and for protein content by the Kjeldahl method. Protein content varied from 16.0 to 22.6%. Correction for seed protein content in the calculation of glucosinolate content by X-RF significantly improved the agreement between the two methods of glucosinolate analysis. The following equation was used in the correction: Y = 14.99 [S(mg g^?1)-protein %/7.5].     

Determination of total glucosinolates in oilseed rape by X-ray spectrometric analysis for oxidised sulphur (S6+)

A rapid X-ray spectrometric (XRS) method has been developed for the determination of the total glucosinolate content of oilseed rape and other Brassica oilseeds. The method is based on analysis for fully oxidised sulphur (S⁶⁺), which includes half the sulphur (S) in the glucosinolate molecule, and the S in sulphate. Results are highly correlated with glucosinolate content determined by glucose release, a standard method widely used in Australia. The relationship is total glucosinolates = (23·97 S⁶⁺ -9·43) r² = 0·987, where the glucosinolate content is expressed as μmol g^?1 and the S⁶⁺ content in mg g^?1. The relationship is applicable to seed of any glucosinolate content and to meal, and is unaffected by changes in protein sulphur content. The correlation of glucosinolates with S⁶⁺ is shown to be closer than the correlation with total S. The latter correlation forms the basis of the existing XRS method, used within the European Community in recent years. The advantages of S⁶⁺ derive from the linearity of the regression and the elimination of errors caused by variation in protein content. The method should be valuable to the Australian oilseed industry because it allows the rapid screening of breeding lines to ensure low glucosinolate content and the assessment of deliveries for crushing and of meal.     

The response of double-low winter oilseed rape to fertiliser sulphur

The effect of soil-applied ammonium sulphate (10, 20, 30, 50 and 80 kg S ha^?1) and agricultural gypsum (20 and 50 kg S ha^?1) and of foliar-applied elemental sulphur (20 kg S ha^?1) on the seed yield and chemical composition of double-low cultivars of winter oilseed rape was determined at 11 sites in England during 1989-1991. Significant (P ? 0.05) mean seed yield responses to applied sulphur (S) of 10 and 17% were obtained at two sites on sandy soils in northern England which showed symptoms of severe S deficiency. At a third site on a shallow calcareous soil in south-west England, which did not show S deficiency symptoms, seed yield was consistently but not significantly increased by an average of 8%. At one of the sites in 1989, application of ammonium sulphate caused leaf scorch and, at the maximum rate of S applied, seed and oil yield were decreased. No conclusions were reached regarding the amount of S required for maximum yield response. The S treatments decreased seed oil content by an average maximum of 9 mg g^?1. Seed glucosinolate content was increased by a greater amount at the two sites in northern England compared to other sites, where increases averaged only 3 μmol g^?1. Analysis of individual glucosinolates in the harvested seed from one of the sites in northern England showed that only the alkenyl glucosinolates were increased by S application. Yield responses were best predicted by total S concentrations and N : S ratio values in young fully-expanded leaves at flowering. Foliar-applied elemental S was consistently less effective in raising leaf S content than ammonium sulphate. Gypsum was occasionally found to be less effective than ammonium sulphate as an S fertiliser.     

Effect of processing on the antinutrient content of rapeseed

The effects of dry extrusion of mixtures of rapeseed and soya bean on total and individual glucosinolates, selected glucosinolate hydrolysis products, myrosinase, sinapine and tannins have been compared with those of more conventional processing, e.g. lime treatment, micronisation and ammoniation. Extrusion at 150°C effectively inactivated myrosinase but had relatively little effect on glucosinolate content unless chemicals were added before extrusion; the most effective combination, 5% alkali+1% ferrous sulphate, reduced the total glucosinolate content by 80%. Under the latter conditions very high (>30 μmol g^?1 defatted meal) levels of nitriles were produced, leading to the suggestion that nitriles in addition to oxazolidine-2-thione and isothiocyanates be used to monitor the effectiveness of processing techniques. None of the extrusion conditions showed any significant effect on reducing sinapine or tannin contents. In view of the chemical data presented, and the probable adverse effects which the processing conditions selected have on the nutritional value of the processed meal it seems unlikely that extrusion will play a significant role in rapeseed detoxification.     

Rapeseed meal and egg taint: Effects of B. campestris meals,progoitrin and potassium thiocyanate on trimethylamine oxidation

The inclusion of Candle (low glucosinolate) and Yellow Sarson (high glucosinolate) rapeseed meals in the diet of laying hens (100 g kg^?1 for 14 days) depressed the oxidation of trimethylamine (TMA) by about 34% and 77% respectively and raised the mean TMA content of their eggs to 0.56 and 1.47 μg g^?1. A dehulled, extracted Yellow Sarson meal had only a slight effect. A high glucosinolate B. napus meal suppressed TMA oxidation almost completely when fed for only 4 days. Differences in the tainting potential of the meals were related to their progoitrin contents. When fed alone this substance had a comparable effect on TMA oxidation which was due to the formation of goitrin in the gastrointestinal tract and its inhibition of TMA oxidase. Potassium thiocyanate (250 and 1000 mg kg^?1 diet for 14 days) had no effect on TMA oxidation. It is concluded that neither the breeding of low glucosinolate cultivars of rapeseed nor treatment of the meal is likely to provide a practicable solution to the taint problem and that the elimination of the tainting defect from commercial stock by selective breeding would be more effective.     

Further studies on the sources of thiocyanate ion in the excreta of poultry fed low-glucosinolate rapeseed (Brassica napus) meal

Balance trials utilising intact (control) and caecectomised laying hens to emphasise hindgut fermentation were conducted to further investigate the sources of thiocyanate ion (SCN) in the excreta of poultry fed lowglucosinolate rapeseed (Brassica napus L) meal (LG RSM). Meals varying in amounts of indole glucosinolate degradation products were prepared from defatted low-glucosinolate rapeseed by subjecting this meal to varying degrees of heat treatment and by solvent extraction. Final quantification of degradation products was conducted on commercial LG RSM. Lack of correspondence between indole glucosinolates decomposed and SCN released in hindgut fermentation indicated the presence of an unidentified thermal degradation product(s) of indole glucosinolates in defatted low-glucosinolate rapeseed subjected to prolonged (60 min) heat treatment and in commercial LG RSM. The concentration of the degradation product(s) was estimated to be 1.4-1.9 μmol g^?1 in two samples of LG RSM. Fractionation experiments showed the compound(s) to be relatively insoluble in ethanol when compared with intact indole glucosinolates. Hindgut fermentation of hydroxybenzyl-glucosinolate resulted in a low production of SCN, and laying hens were shown to excrete free SCN readily.     

Comparative assessment of soybean meal with high and low glucosinolate rapeseed–mustard cake as protein supplement on performance of growing crossbred calves

BACKGROUND: Feeding of high glucosinolate rapeseed–mustard cakes (RMCs) imparts adverse effects on dry matter (DM) intake, health and overall performance of animals. Recently, plant breeding efforts have resulted in many cultivars of RMCs containing low to moderate levels of glucosinolate in India. The feeding value of RMC cultivars with high and low glucosinolate was evaluated relative to commonly used soybean meal as a protein supplement in growing crossbred calves. RESULTS: Eighteen growing crossbred calves (62.9 ± 3.8 kg body weight) were randomly allocated to three dietary treatments SBM, LG and HG containing soybean meal, low glucosinolate B. napus (15 µmol glucosinolates g^?1) and high glucosinolate B. juncea (135 µmol glucosinolates g^?1), respectively. Although daily intake of total DM and wheat straw did not differ (P > 0.05) among the dietary treatments, intake (g/kgW^0.75) of concentrate moiety decreased quadratically (P < 0.01) with increasing glucosinolate levels in diets. Nutrient digestibility and balances of N, Ca and P by calves were similar (P > 0.05) among dietary treatments. However, average daily gain (g) decreased and feed conversion ratio values increased quadratically (P < 0.05) with increasing glucosinolate levels. Serum metabolic profile and triiodothyronine remained within the normal range; however, thyroxine changed quadratically. CONCLUSION: The results suggested that while high glucosinolate RMCs may reduce the palatability and consequently growth rate in crossbred calves, SBM can be replaced completely by low glucosinolate rapeseed without compromising their performance. Copyright © 2008 Society of Chemical Industry     

Sulfate determines the glucosinolate concentration of horseradish in vitro plants (Armoracia rusticana Gaertn., Mey. & Scherb.)

BACKGROUND: Horseradish plants (Armoracia rusticana) contain high concentrations of glucosinolates. Former studies have revealed that Armoracia plants cultivated in vitro have markedly lower glucosinolate concentrations than those grown in soils. Yet, these studies neglected that the sulfate concentration in the growth medium may have had a strong impact on glucosinolate metabolism. Accordingly, in this study horseradish in vitro plants were cultivated with differing sulfate concentrations and the glucosinolate concentrations were quantified by ion pair HPLC. RESULTS: Cultivation in 1.7 mmol L^?1 sulfate (as used in the prior studies) resulted in the accumulation of 16.2 µmol g^?1 DW glucosinolates, while the glucosinolate concentration increased to more than 23 µmol g^?1 DW when 23.5 mmol L^?1 sulfate was used in the medium. Correspondingly, the glucosinolate concentration decreased to 1.6 µmol g^?1 DW when sulfate concentration was lowered to 0.2 mmol L^?1. CONCLUSION: Since the glucosinolate accumulation in relation to the sulfate concentration follows a typical saturation curve, we deduce that the availability of sulfate determines the glucosinolate concentration in horseradish in vitro plants. © 2012 Society of Chemical Industry     

Comparative effects of sulfur and nitrogen fertilization and post‐harvest processing parameters on the glucotropaeolin content of Tropaeolum majus L.

Under natural conditions, the content of the bioactive compound glucotropaeolin in the vegetative tissue of Tropaeolum majus is too low to be used directly for the preparation of a mono‐drug. In the present study the influence of sulfur and nitrogen fertilization and the post‐harvest drying procedure on the glucotropaeolin content was evaluated in order to minimize losses of the active glucosinolate. In 2001, field experiments with three levels of nitrogen and sulfur fertilization were conducted on two different sites. Nitrogen fertilization had no consistent influence on the glucotropaeolin content while sulfur fertilization with 100 kg S ha^?1 enhanced the glucotropaeolin content in leaves and seeds significantly by factors of 1.4–2.1 and 1.6–1.8, respectively. The results of the post‐harvest treatment showed that a gentle drying procedure at 40°C in a ventilated oven induced an increase in the glucotropaeolin content in leaves of 1.4–3.2‐fold (from 10.7–25.5 to 30.9–44.6 µmol g^?1 dry weight) compared to sampling in liquid nitrogen followed by freeze‐drying of the samples. This paper delivers new insights into glucosinolate metabolism that will contribute significantly not only to warrant a high content of bioactive compounds in medicinal plants, but also to promote glucosinolate concentrations in various crops by appropriate post‐harvest treatments. Copyright © 2007 Society of Chemical Industry     

Isoflavone content in soy germ flours prepared from two drying methods

Isoflavone glucosides and aglucons in various soybean varieties (Chiang Mai‐60, S.J.‐5, Chiang Mai‐2, Srisumrong‐1, and Nakhonsawan‐1) harvested from dry vs. rainy seasons were quantified. Isoflavone contents of all soy germs ranged from 16.5 to 30.6 μmol g^?1. Regardless of varieties, isoflavone contents in germ of seeds from dry season were higher (P < 0.05) than those from rainy season. The Chiang Mai‐60 germ, having the highest isoflavone content (30.6 μmol g^?1), was selected for germ flour production. Freeze‐dried germ flour contained higher isoflavone aglucons (17.72 μmol g^?1 daidzein; 6.48 mg g^?1 glycitein; 4.28 μmol g^?1 genistein) than those (15.07; 5.59; 3.41) of drum‐dried germ flour. However, isoflavone glucoside contents in freeze‐dried germ flour (3.27 μmol g^?1 daidzin; 1.86 μmol g^?1 glycitin; 1.41 μmol g^?1 genistin) were lower than those (5.22; 3.15; 1.89) of drum‐dried germ flour. Total isoflavone contents of drum‐dried and freeze‐dried germ flours were comparable (34.32 vs. 35.02 μmol g^?1) but more than that (30.16 μmol g^?1) of unprocessed germ flour.     

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.     

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     

Distribution of glucosinolate and pungent odors in rapeseed oils from raw and microwaved seeds

The current study was aimed to investigate the effect of glucosinolate degradation on the flavor precursors and pungent odors in raw and microwaved rapeseeds. Five isothiocyanates and six sulfur compounds were identified using comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry (GC× GC-TOF/MS). Comprehensive analysis with headspace solid-phase microextraction (HS-SPME) and aroma extract dilution analysis (AEDA) with altering split ratio showed that 1-isothiocyanato butane, allyl isothiocyanate and 4-isothiocyanato-1-butene were responsible for the sulfur, pungent and green odors in rapeseed oils, due to their high flavor dilution factor. Dimethyl sulfide, dimethyl trisulfide and dimethyl sulfoxide, might be derived from methionine or isothiocyanate rearrangement reactions imparted onion-like, cabbage-like, garlic-like, and sulfurous-pungent odors. Rapeseed samples were heated in a microwave for seven minutes, and the total glucosinolate content decreased from 28.2 ± 0.8 μmol/g to 14.5 ± 0.6 μmol/g in Brassica napus, from 101.2±3.0 μmol/g to 42.2 ± 5.4 μmol/g in Brassica campestris, and from 132.02 ± 9.31 μmol/g to 52.50 ± 6.50 μmol/g in Brassica juncea, compared to untreated ones. Differences in the concentrations of six main odorants and the glucosinolate precursors from genetic types were responsible for the intensity of the pungent odors in raw and microwaved rapeseeds. The result can assist to determine the flavor of the commercial rapeseed oils.     

Detoxification of commercial united kingdom rapeseed meal by glucosinolate hydrolysis with exogenous myrosinase and the extractability of the aglucones by aqueous industrial methylated spirits

The aims of this study were to investigate the detoxification of United Kingdom commercial rapeseed meal by alcoholic extraction of aglucones released after treatment with mustard seed myrosinase. Aglucones released from the commercial rapeseed meal were compared with those resulting from autolysis of laboratory-defatted rapeseed. 3-Butenyl isothioc yanate, 5-vinyl-oxazolidene-2-thione (VOT) and 1-cyano-2-hydroxy-3-butene were detected in commercial rapeseed meal after glucosinolate hydrolysis. In comparison, autolysis of rapeseed at 5°C gave VOT, 1-cyano-2-hydroxy-3-butene and epithionitriles, but at 60°C epithionitrile release was significantly reduced. In addition, 1-cyano-3,4-epithiobutane was detected in the autolysed samples. Aglucones released at 40°C from commercial rapeseed meal by mustard seed myrosinase were 85% extractable in 60–90% (v/v) aqueous industrial methylated spirits. Extraction was significantly higher than previously reported for the intact glucosinolate. Double extraction of the myrosinase-treated meal with 80 % (v/v) aqueous industrial methylated spirits gave a meal with no detectable intact glucosinolate or aglucone content.     

利用图像分析和深度学习预测油菜籽中总酚含量

目的 建立了一种结合图像分析和深度学习的油菜籽中总酚含量的快速预测方法。方法 利用VGG19网络进行油菜籽图像籽粒特征的提取,通过多个卷积层来学习油菜籽图像的特征,并建立了回归模型用于预测油菜籽的总酚含量。共收集了100种油菜籽样本,将油菜籽样本按照3:1的比例划分为训练集和测试集,利用均方损失函数(MSELoss)和决定系数(r2)评估模型预测准确性。结果 测试集MSELoss=0.0085、r2=0.9914,表明该预测模型具有一定的准确性和实用性。结论 本研究提出了一种快速、准确的评估油菜籽总酚含量的方法,为油菜籽的总酚测定提供一种快速、准确的智能化检测方法。     

Changes in yield and seed quality traits in rapeseed genotypes by sulphur fertilization

Sulphur is considered more as a soil amendment to remedy alkaline soils rather than a fertilizer in crop production. However, as one of the macronutrients, just as N–P–K, it is able to have a direct and significant effect on yield and quality in some crops. There might be a sound potential of increasing seed yield and quality of rapeseed, the second important oil crop around the world, with the use of sulphur as a fertilizer in cultural practices. Our objective in this study is to determine the effects of sulphur fertilization on seed yield and several seed and oil quality traits in rapeseed. Five rapeseed genotypes were grown for two consecutive growing seasons in Çanakkale, in a RCB design with three replications. The experimental plots were given 0, 100 or 200 kg ha^?1 sulphur along with a fixed amount of 240 kg ha^?1 N. Results indicated that sulphur fertilization had positive effects on seed yield and some of the seed and oil quality components. On the other hand, excessive sulphur fertilization, or naturally occurring high levels in the soil, may have adverse effects in elevating some undesired compounds, such as glucosinolates.     

Observations on nitrile production during autolysis of kale and swedes,and their stability during incubation with rumen fluid

A method was modified for quantitatively measuring total nitriles produced from glucosinolate degradation during autolysis of kale and swede plant tissue. Nitrile production from New Zealand Medium Stem kale was less at pH 7.5 (0.28 mol mol^?1 glucosinolate) than at pH 5.7 (0.57 mol mol^?1 glucosinolate). Lower levels were produced from Maris Kestrel kale, due both to a lower glucosinolate content and to reduced conversion of glucosinolate to nitriles. The amount of nitrile obtained on conversion of glucosinolate tended to be reduced by growing New Zealand Medium Stem kale in soil of low SO₄-S concentration, due to a reduction in plant glucosinolate content. Nitrile production from swede tissue was 0.3–0.5 mol mol^?1 glucosinolate. Nitriles produced from swedes were rapidly degraded upon incubation with rumen fluid (4 h), whereas nitriles produced from kale remained stable for incubation periods up to 23 h. The high rate of conversion of glucosinolate to nitriles coupled with their stability in rumen fluid suggests that, in addition to goitrogenic properties, nitrile formation also deserves attention in the nutrition of ruminant animals fed kale diets. Of the four brassica diets tested, New Zealand Medium Stem kale is considered the most likely to cause nutritional problems (depressions in intake and reproduction) from nitrile production, and a method of testing this is suggested.     

Daily Variation in Glucosinolate Concentrations in the Leaves and Roots of Cabbage Seedlings in Two Constant Temperature Regimes

Limited information is available on the glucosinolate variation within the Brassica plant and the relationship between the pattern and concentration of glucosinolates in the aerial parts and the roots has received little attention. Early studies carried out under field conditions have shown that glucosinolate levels may vary considerably throughout a 24 h period. The purpose of the present study was to show whether, under controlled conditions, temperature was a factor in glucosinolate variation and to determine whether such variation might be due to translocation of glucosinolates between the aerial parts of the plant and its roots. Cabbage seedlings were maintained at 20 and 30°C over 2 days and leaves and roots sampled at 02:00 h, 06:00 h, 10:00 h, 14:00 h, 18:00 h and 22:00 h. The glucosinolates 2-propenyl- and 3-methylsulphinylpropyl- with an average of 261 and 167 μmol 100 g^-1 DW, respectively, were the two main glucosinolates in the aerial part of the plant whilst in the roots 1-methoxyindol-3-ylmethyl-, 2-phenylethyl- and 3-methylsulphinylpropyl, with 495, 495 and 385 μmol 100 g^-1 DW respectively, showed the highest average concentrations. Total and individual glucosinolates in the roots and in the aerial part of the plant showed the highest concentrations in the dark cycle, at 02:00 h and 22:00 h, respectively, whilst the lowest levels were during the light cycle, mainly at 18:00 h. The results suggest that temperature was not a major factor in the short-term variation in glucosinolate levels. Although there was a very high significant difference between the total glucosinolate levels in the aerial part of the plant (581 μmol 100 g^-1 DW) and roots (2124 μmol 100 g^-1 DW), the results of the present study do not support the concept of translocation between aerial part and roots, suggesting that other factors may be involved. © 1997 SCI.     

Myrosinase activity of cruciferous vegetables

Myrosinase activity in partially purified extracts of 12 cruciferous vegetables and an acetone powder preparation of Sinapis alba L. (white mustard) was determined by the initial rate of glucose formation from glucosinolate hydrolysis using a coupled assay. Of the species studied Raphanus sativus L. (radish, 12.8±0.7 μmol min^?1g^?1 powdered tissue) had the greatest myrosinase activity, and Brassica campestris L. ssp. rapifera (turnip) and Nasturtium officinalis R.Br. (watercress) (0.6±0.1 and 0.8±0.03 μmol min^?1g^?1 powdered tissue respectively) the least. The sub-species of Brassica oleracea studied all had similar myrosinase activity (ca 2.5±0.2μmolmin^?1g^?1 powdered tissue) except B. oleracea L. var. gemmifera D.C. (Brussels sprouts) and B. oleracea L. var. capitata L. (white cabbage) which had higher activities (7.6±0.1 and 5.2±0.2μmol min^?1g^?1 powdered tissue respectively). The effect of ascorbate concentration upon the myrosinase activity of six of the crucifers studied and the white mustard preparation, revealed that the ascorbate concentration necessary to promote maximal activity varied with species. A concentration of 0.9mM ascorbate maximally activated radish and turnip myrosinase, while red cabbage, watercress, white mustard and Brussels sprouts were maximally activated at 2.0, 3.0, 5.0 and 0.7–1.0mM ascorbate respectively. Two peaks of maximal myrosinase activity, occurring between 0.9 and 1.0mM and at 3.0mM ascorbate, were found for B. oleracea L. var. botrytis L. subvar. cauliflora D.C. (cauliflower).     

Aflatoxins in sunflower and safflower seeds from Iran

Aflatoxin content of 173 sunflower and safflower seeds was determined by HPLC with immunoaffinity column (IAC) clean-up and fluorometric detection. Aflatoxin B₁ contamination was found in 111 samples: in 8 of the sunflower seed samples (16%) at a mean level of 40.68?ng?g^?1 and in 103 safflower seed samples (83.7%) at a mean level of 2.81?±?0.44?ng?g^?1. In 5 sunflower seed samples and 1 safflower seed sample, aflatoxin B₁ levels were higher than the maximum levels of AFB₁ under Iran regulations (5?ng?g^?1). Aflatoxin B₁ levels in 5 sunflower and 2 safflower seed samples were higher than the European Union maximum limit (2?ng?g^?1).