Rapeseed meal-glucosinolates and their antinutritional effects. Part II. Flavour and palatability

This paper has reviewed the current literature relating to the effects of glucosinolates on the palatability of rapeseed meal. The available evidence indicates that diet palatability can be adversely affected by rapeseed meal inclusion and that this response is related to glucosinolate level. However the response is variable and depends also on the species of animal, age and growth state. Younger animals, particularly chicks, piglets and calves appear to be more severely affected and exhibit reduced intake and hence depressed performance with diets containing high levels of glucosinolates from high glucosinolate rapeseed meal. Palatability is substantially improved by the use of low glucosinolate rapeseed meal (LG-RSM) containing 10–30 μ/g and very low glucosinolate rapeseed meal (VLG-RSM) containing 1–5 μ/g glucosinolates. From the findings of this review, it can be concluded that LG-RSM and VLG-RSM can be included at levels up to 20% and 30% for calves and dairy cows respectively. Since piglets are particularly sensitive it is suggested that rapeseed is excluded from early starter diets but that low glucosinolate meals can be included at levels of 10% and 15% for grower and finisher pigs respectively. Growing poultry may be less sensitive to palatability problems associated with rapeseed meal but the use of high levels is constrained due to the lower energy and higher fibre contents of RSM compared with soybean meal.     

菜籽粕发酵饲料的研制

通过单菌株、多菌株生料固态通风发酵试验,研制出了低硫代葡萄糖苷、高蛋白含量的菜籽粕发酵饲料,其硫苷含量为0.11μmol/g(干基),降解率达99.66%,粗蛋白含量为50.13%(干基)。     

混菌固态发酵菜籽粕制备菜籽肽的菌种筛选

通过平板培养和混菌发酵相结合的方法筛选固态发酵菜籽粕制备菜籽肽的最佳菌种,以硫苷降解率为指标评价其硫苷降解效果。结果表明:枯草芽孢杆菌与雅致放射毛霉混菌发酵效果最好,发酵后所产生的低分子量菜籽肽含量高于其他混菌,适合混菌发酵生产菜籽蛋白肽;枯草芽孢杆菌与宇佐美曲霉混菌发酵的硫苷降解效果较好,可进行后续脱毒实验的研究。     

Rapeseed meal-Glucosinolates and their antinutritional effects Part 6. Taint in end-products

From the present review it is clear that glucosinolates and their breakdown products may pass in small amounts into such products as meat, milk or eggs without noticeable deterioration in their taste. When applying low glucosinolate rapeseed meal (LG-RSM) as the sole high protein component of concentrate mixture for cows, the level of rapeseed glucosinolates breakdown products should not exceed 0.1 μmol/1 oxazolidinethione, 10 μmol/1 unsaturated nitriles and 100 μmol/1 thiocyanate. At these levels no evidence has been found to indicate the negative influence of glucosinolates breakdown products on the sensory properties of milk or threat for consumers. No published information appears to be available suggesting that glucosinolates have any deleterious effect on the carcass flavour in cattle. Even at a 20% inclusion of LG-RSM in diets no impairment on visual scores or sensory evaluation was found in pig's or broiler's carcass. Glucosinolated, chiefly progoitrin, which depress trimethylamine oxidation thus clearly affect the taint in eggs. In birds with genetically conditioned susceptibility (brown layers) fishy taint can be observed even at 0.3 μM progoitrin, i.e. approximately 0.5 μM total glucosinolates in 1 g diet. Assuming a threefold higher threshold for white layers (1 μM progoitrin in 1 g diet) fishy taint can be expected at a 10% LG-RSM level in diet, and only very low glucosinolate rapeseed meals can be fed to layers without the risk of fishy taint in eggs.     

油菜籽及其饼粕中硫代葡萄糖苷总量快速测定方法的研究

本研究对油菜籽及其饼粕中硫代葡萄糖苷总量的检测方法进行了研究和试验，将葡萄糖释放——酶鉴定法作为快速检测的首选方法。在试验中发现了葡萄糖释放——酶鉴定法和硫酸根离子沉淀法检测结果之间呈线性相关并建立了线性方程，对这两种方法的适用性进行了比较。     

Rapeseed meal-glucosinolates and their antinutritional effects Part 5. Animal reproduction

Although there is no clear evidence to fully describe the mechanism involved in glucosinolate-related effects on animal reproduction, lowered fertility in animals fed diets with rapeseed meal (RSM) inclusion is related to glucosinolate content in the diet. Negative effects can result both from multidirectional action of glucosinolates, malnutrition of mother due to the thyroid dysfunction, transfer of goitrogenic compounds to foetus and reduced transfer of nutritive compounds (e.g. iodine) through the placenta. The degree of reproduction impairment depends both on glucosinolate content and on the type of animal. Pregnant female rats are sensitive to the presence of glucosinolates, and the first symptoms of fertility impairment and lowering of offspring survival rate may occur at low glucosinolate levels, e.g. with diets containing low glucosinolate rapeseed meal (LG-RSM). In the case of swine, the limiting value above which sows fertility may be impaired is 4 μmol of total glucosinolates per g diet and 8 mmol of daily intake of these compounds. Opinions on the permitted RSM inclusion in diet for hens are very divergent. Some authors recommend limiting of the RSM inclusion to 10%, while others did not find any lowering of egg production in hens fed diets with two- or three-fold greater RSM inclusion rates. Most long-term experiments with heifers, cows and ewes indicate that ruminants tolerate the level of glucosinolate in LG-RSM although feeding this fodder as the only high-protein concentrate component may lead to impaired fertility.     

高产酸菌株的筛选、鉴定及其混菌发酵对菜籽粕营养价值的影响

本实验从泡菜水中分离得到一株高产有机酸的乳杆菌,并将该菌株与黑曲霉混合后结合两步法处理菜籽粕,同时降解菜籽粕中的硫苷和大分子蛋白并提高总酸含量,从而提高菜籽粕的营养价值。该株乳杆菌经16S rDNA鉴定,确定为类食品乳杆菌(Lactobacillus paralimentarius)。将该菌株与黑曲霉混合后结合两步法处理菜籽粕后,其营养价值得到了一定提高,与空白对照和单菌发酵相比,总酸含量分别提高了640.54%、160.95%和112.40%;酸溶蛋白和氨基酸态含量分别从2.87%和0.12%提高到19.08%和1.23%;硫苷含量从23.09 μmol/g下降到12.65 μmol/g。结果表明,混菌发酵结合两步法有利于改善菜籽粕的营养价值,对扩大菜籽粕的利用奠定了基础。     

低能耗菜籽双液相萃取技术

采用少量适当的助剂，处理菜籽双液相萃取加工时得到的甲醇相母液，可使母液不经提纯，直接大比例才新鲜甲醇相一起继续用以处理菜籽。母液比例可占处理菜所需甲醇相总量的３／４以上，从而可大大降低过程能耗。所得成品粕品质不变，色浅、酥松、适口性好、蛋白质含量高，硫甙含量低于国家一级饲料标准。     

Influence of glucosinolates and native enzymes on the nutritional value of low-glucosinolate rapeseed meal.

This study attempted to find out whether the low content of glucosinolates in the seed of the rapeseed cultivar Bronowski significantly affects the nutritional value of the seed meal. Glucosinolates were extracted from unheated meal with cold acetone, a process giving rise to only a slight inactivation of enzymes. Mice fed with a diet containing this meal as the protein source showed similar growth, feed intake and protein efficiency ratio to mice fed with heat-treated meal. When glucosinolates were added to the acetone-extracted meal, bringing them to about the same amount as before the acetone extraction, the growth response of the mice was as poor as that of mice fed with unheated, unextracted meal. Thus, even such low amounts of glucosinolates as found in Bronowski seed meal significantly affect the nutritional value of the diet as long as the appropriate enzymes are present. Besides myrosinase, other enzymes influencing the hydrolysis of glucosinolates appear to exist in the meal.     

7 种十字花科种子中黑芥子酶降解油菜籽饼粕中硫苷的产物比较分析

比较7 种十字花科植物种子中的黑芥子酶的活性,利用气相色谱-质谱法（gas chromatography-massspectrometry,GC-MS）分别测定这7 种黑芥子酶降解油菜籽饼粕中硫代葡萄糖苷（简称硫苷）的产物组分和相对含量。结果表明：7 种来源的黑芥子酶比活力存在差异（P＜0.05）,比活力由高到低依次为西兰花籽黑芥子酶（broccoli seeds myrosinase,BSm）、油菜籽黑芥子酶（rape seeds myrosinase,RPSm）、白菜籽黑芥子酶（whitecabbage seeds myrosinase,WCSm）、萝卜籽黑芥子酶（radish seeds myrosinase,RDSm）、芥蓝籽黑芥子酶（kaleseeds myrosinase,KSm）、甘蓝籽黑芥子酶（cabbage seeds myrosinase,CSm）和芥菜籽黑芥子酶（mustard seedsmyrosinase,MSm）。GC-MS比较分析7 种黑芥子酶降解油菜籽饼粕中硫苷的产物发现,RPSm降解产物有6 种,即1-丁烯基-4-异硫氰酸酯、烯丙基异硫氰酸酯、2-苯乙基异硫氰酸酯、苯丙腈、致甲状腺肿素和2,1-苯并异恶唑。CSm降解产物中1-丁烯基-4-异硫氰酸酯含量最高（33.22%）,RPSm次之,含量为32.20%,而MSm降解产物中未检测到。WCSm、KSm、MSm和CSm降解产物中检测到新组分丁基异硫氰酸酯。与RPSm降解产物相比,其他6 种黑芥子酶降解产物中恶唑类及腈类物质种类增多,有4 种恶唑类和3 种腈类,但降解产物中未检测到2,1-苯并恶唑。不同来源的黑芥子酶在相同环境下降解油菜籽饼粕中的硫苷的产物种类和相对含量存在明显差异,虽RPSm活性低于BSm,但其降解产物中恶唑类及腈类种类最少,含量最低,是较好的降解油菜籽饼粕中硫苷的酶源。     

菜籽粕硫甙生物降解工艺优化及其动力学研究

目的 优化菜籽粕硫甙降解工艺,并研究生物发酵过程中优势菌株对硫甙的降解动力学。方法 以菜籽粕为原料,以实验室自筛菌种B38(鉴定为短小芽孢杆菌Bacillus pumilus)与商业菌株(植物乳杆菌LP21825、枯草芽孢杆菌BS20445)进行复配,确定最佳硫甙降解菌株组合,进一步优化硫甙降解工艺,并对降解率进行拟合,选用Logistic方程来适配发酵过程中硫甙浓度的变化。结果 结果表明B38+BS20445为最佳菌株组合,确定最佳硫甙降解工艺为料液比1:1.5(g:mL),发酵时间48h,接种量10%,此时硫甙降解率为56.66%,并且菜籽粕经发酵后蛋白含量与酸度均有所增加。硫甙生物降解过程符合Logistic动力学方程,其R²大于0.99,表明拟合性良好,进一步说明模型能够很好地描述和预测菜籽粕硫甙的降解过程。结论 菌种复配发酵能提高菜籽粕硫甙降解率,降低菜籽粕毒性,为菜籽粕的应用提供重要理论基础。     

Gas chromatographic determination of indole glucosinolates—a re-examination

The use of gas-liquid chromatography (g.l.c.) as a technique for the analysis of glucosinolates, including indole glucosinolates, in low-glucosinolate rapeseed meal and seed was assessed. Variation contributed by various steps of g.l.c. methodology was studied, and following modifications to the method analytical results were compared with those estimated from thiocyanate ion (SCN) release following treatment of samples with myrosinase enzyme. The volume of water required to effectively elute glucosinolates from a DEAE Sephadex column was shown to cause variability in analytical results. The effect was dependent upon the internal standard used and was most pronounced for indole glucosinolates. Heat treatment (95°C) required in the procedure for the inactivation of myrosinase enzyme was shown to result in substantial decomposition of indole glucosinolates. In this regard a standard procedure involving 15 min dry heat treatment followed by 3 min wet heat treatment is recommended. With these modifications the g.l.c. methodology was shown to be adequate as a routine procedure for the analysis of glucosinolates in low-glucosinolate rapeseed meal and seed.     

Rapeseed: Constituents and protein products Part I. Composition and properties of proteins and glucosinolates

The review concerns with value-determining nonlipidic components from rapeseed, especially the structure, the content and the distribution of proteins and glucosinolates in different species and varieties. Furthermore structural changes and their effects on the composition and properties are summarized.     

菜籽饼粕生物转化与高值化利用技术研究进展

菜籽饼粕是一种利用价值很高的优质植物蛋白资源。由于饼粕中存在硫甙、芥酸、植酸等多种有害成分和抗营养因子,其利用价值和应用范围受到极大限制。生物技术法对于改善饼粕饲用品质、提升综合利用价值、拓宽应用领域等方面具有独特的优势。本文重点介绍了生物技术法在饼粕脱毒、饲用品质改良、发酵生产食用菌和酶制剂等产品的生物转化与高值化利用方面的最新研究进展,并概述了生物技术法应用于饼粕的发展方向。     

Functional Properties of Chinese Rapeseed Protein Isolates

A membrane-based protein isolation process developed in our laboratory produced two protein isolates from CH₃OH/NH₃/H₂O-hexane-extracted Chinese rapeseed meal. Both contained ～99% protein (NX6.25), and they were essentially free of glucosinolates or their breakdown products (<2,2 μmol/g). Their functional properties were evaluated and compared with a commercial soybean protein isolate. The precipitated isolate gave high values for all properties except nitrogen solubility index (NSI) while the soluble isolate showed excellent NSI and fat absorption but poor emulsification characteristics. They both had good foaming properties. The two Chinese rapeseed protein isolates complemented each other and were comparable to soybean protein isolate in most functions.     

多菌种复合固态发酵对菜籽粕硫甙去除效果的研究

以菜籽粕为原料,选择植物乳酸菌、枯草芽孢杆菌、米曲霉进行单菌和混菌的固态发酵,研究其对菜籽粕硫甙和粗蛋白含量的影响。结果表明,植物乳酸菌对硫甙的降解效果显著高于其他菌种,30℃恒温发酵3d降解率达56.42%;多菌种复合发酵效果优于单菌发酵,当植物乳酸菌:枯草芽孢杆菌:米曲霉的接种比例为9%:6%:6%,pH6.5,水料比为1.2:1,33℃发酵96h,菜籽粕硫甙含量从33.33 μmol/g(干基)下降到2.79μmol/g(干基),降解率可达91.36%(干基),粗蛋白含量提高6.06%(干基),硫甙含量大幅度下降,粗蛋白含量也有所提高。     

菜籽粕硫甙生物降解和脱毒研究进展

饲用菜籽粕中硫甙降解产物是引起动物甲状腺肿大主要因素,利用微生物发酵脱除硫甙成为开发蛋白饲料资源热点;该文对生物降解菜籽粕硫甙机理及近年国内外生物脱毒研究进行综述。     

Use of diabetic test kits to assess the recovery of glucosinolates during isolation of canola protein

A series of canola fractions representing various stages in the protein isolation process were collected to assess the extent of glucosinolate recovery using two ultrafiltration systems. The total glucosinolate level of all fractions was estimated using a diabetic test kit (DTK), One Touch Blood Glucose Meter, to monitor glucose released on hydrolysis of glucosinolates by endogenous myrosinase and results compared to those obtained using gas chromatography (GC). Of the glucosinolates in the meal, approximately 1.9 g/100 g were recovered in the protein isolated from canola meal, regardless of the type of ultrafiltration system. A major reduction in glucosinolates was evident in the ultrafiltration step where, based on GC data, 63% and 39% of the glucosinolates were recovered in the discarded permeate using an Amicon™ stirred cell and Vivaflow™ 200 ultrafiltration, respectively. However, an overestimation of glucose was observed for the DTK results when looking at total glucosinolate recovery, possibly due to the presence of other free glucose in the canola fractions. These findings suggest that low glucosinolate protein isolates can be obtained, in large part due to glucosinolate removal during ultrafiltration of the extracted material. While the DTK method gave good estimates of the glucosinolates in the meal, it cannot be recommended for use with isolation products.     

菜籽粕中抗营养因子及其去除方法的研究进展

油菜籽加工过程中的副产品菜籽粕具有广阔的应用前景,然而由于菜籽粕中硫代葡萄糖甙以及其他一些抗营养因子的存在,使菜籽粕的合理利用受到制约.论述了菜籽粕中的抗营养物质及其毒害作用和去除这些抗营养物质的方法.菜籽粕中的抗营养物质主要有硫代葡萄糖甙及其降解产物、植酸、单宁和芥子碱,可采用物理方法、化学方法、生物方法和遗传学方法对菜籽粕进行脱毒.     

Detoxication of rapeseed meal by Rhizopus Oligosporus sp-T3: A first step towards rapeseed protein concentrate

To obtain proteins from OO rapeseed meal for use in human food, a first step was realized by fermentation with Rhizopus oligosporus spT3 . The meal's fermentation during 40 h resulted in degradation of 84% of carbohydrates, 30% of lignin and other polyphenolic components indigestible by nonruminants, and 47% of total glucosinolates which are responsible for goitre. The fermentation improves the nutritional quality of rapeseed meal by degrading undesirable factors.