菜籽预榨-浸出粕中植酸的提取

为实现菜籽粕的综合开发利用,研究了一种从菜籽预榨-浸出粕中两步提取植酸的工艺.考察了酸洗pH、酸洗时间、碱提pH和碱提乙二胺四乙酸二钠(EDTA)浓度等对植酸提取的影响.将经过复合纤维素酶水解的菜籽粕在pH 5.0和50℃下酸洗3h获得酸洗液,然后用EDTA浓度0.1mol/L的碱性溶液在pH 12.0和50℃下碱提酸沉获得乳清液,经以上两步可将菜籽粕中的植酸基本提取完全.将提取液中的粗植酸经氢氧化钙沉淀并酸化,再经离子交换可获得纯度为69.96％、提取率为58.0％的植酸产品.     

以脱皮冷榨双低菜籽粕为原料制备菜籽分离蛋白的研究

以脱皮冷榨双低菜籽粕为原料,采用单因素试验和正交试验,对菜籽分离蛋白碱溶二次酸沉制备工艺进行了研究.结果表明,影响分离蛋白提取率的因素中,浸提pH影响最大,液固比次之,提取时间影响最小.优化的制备条件为:pH 11.0,液固比15:1,提取时间30 min,提取温度60℃.该条件下蛋白质提取率为87.69%,产品中蛋白质含量为77.45%.     

油菜籽粕酶解液对甜瓜采后品质的影响

以新疆甜瓜为试材,分析在温度25℃、相对湿度55%~60%条件下,油菜籽粕酶解液对甜瓜采后贮藏品质及生理指标的影响。结果表明,与对照组相比,油菜籽粕酶解液能够有效降低甜瓜的呼吸强度、质量损失率和相对电导率,维持果实硬度、糖酸和V_C的含量,抑制丙二醛的增加,提高过氧化物酶活性,较好地保持了果实的品质和风味,说明油菜籽粕酶解液可以作为天然保鲜剂应用于甜瓜采后贮藏保鲜。     

微生物发酵改善菜籽粕品质的研究

采用实验室筛选的菌种混合固态发酵菜籽粕,比较菜籽粕发酵前后硫甙、粗蛋白质、菜籽肽、乳酸含量以及蛋白质体外消化率的变化.结果表明,菜籽粕中的硫甙降解率为53.4%,粗蛋白质含量从39.99%提高到45.84%,菜籽肽含量由2.48%提高到10.58%,氨基酸的组成和含量也有一定的变化和提高,蛋白质的快速体外消化率提高了1.94%,有益代谢产物乳酸的含量由1.03%提高到2.53%.     

The effects of breed,sex, intramuscular fat and ultimate pH on pork tenderness

A study was conducted to evaluate the influence of breed and sex of animals on tenderness of pork. For evaluation, carcasses of pure breed barrows and gilts of Large White, Czech pig meat, Landrace and Duroc were used. For laboratory investigations, the samples of musculus longissimus lumborum et thoracis (20 mm thick) were taken from the same place, at the first cruciate vertebra 48 h post mortem. Seven days post mortem, the texture of heat-processed meat was measured objectively by the shear method on Instron equipped with Warner–Bratzler shear device. Meat tenderness and juiciness were also evaluated sensorially. It was observed that the tenderness of cooked meat is influenced by breed (the tenderest meat was from Duroc breed). The sex of animals has significant effect on meat tenderness too. At the same time, the effects of pH 45 minutes (pH₄₅) and 24 hours (pH₂₄) post mortem and intramuscular fat content on meat tenderness were evaluated. Correlations were found between shear force (tenderness) and intramuscular fat content and also between shear force and pH value 45 min post mortem. The shear force decreased with increasing intramuscular fat content and with increasing pH₄₅ value. Sensory evaluation of tenderness confirmed the objectively measured data.     

菜籽饼粕中多肽的提取纯化及抗肿瘤活性

从菜籽饼粕中分离纯化多肽,并验证其抗肿瘤活性.采用超声-微波协同萃取法获得菜籽饼粕总蛋白,通过碱性蛋白酶水解提取菜籽饼粕总多肽,连用分子排阻色谱和反相高效液相色谱纯化获得菜籽饼粕多肽(RMP).通过对Hela细胞生长的抑制作用评价RMP的抗肿瘤活性.结果 显示:RMP由8个氨基酸组成,序列为Asp-Val-Phe-Va...     

Changes in fatty acid composition and improved sensory quality of backfat and meat of pigs fed bacterial protein meal

A total of 48 pigs (11.4 and 107.2 kg initial and final weight) were used to evaluate increasing dietary levels of bacterial protein meal (BPM) produced on natural gas (0, 50, 100, or 150 g kg⁻¹) on fatty acid composition, sensory properties, and susceptibility of pork to lipid oxidation. Increasing levels of BPM to diets increased the content of C16:1 fatty acids in backfat and muscle and total monounsaturated fatty acids in muscle, but decreased the content of polyunsaturated fatty acids and iodine value in backfat and muscle. Pigs fed diets containing BPM had reduced thiobarbituric acid reactive substances (TBARS) value in backfat and muscle, reduced intensity of odor and rancid odor and taste in pork after short-time storage, and reduced off-odor and off-taste after intermediate-time storage. To conclude, adding BPM to diets for pigs changed the fatty acid profile, improved the oxidative stability, and sensory quality of pork.     

发酵前后菜粕的风味成分分析

菜粕是我国重要的饲料蛋白源。本实验采用固相微萃取-气质联用的方法分析了普通菜粕、脱皮低温压榨菜粕、发酵普通菜粕和发酵脱皮低温压榨菜粕的风味物质的组成。结果表明,硫甙降解产生的腈类和胺类物质是形成菜粕风味的重要化合物,其中最主要的分别是苯代丙腈和烯丙胺。经发酵后,不仅菜粕中硫甙含量降低,而且产生了酸类和醇类等有助于改善菜粕风味的物质。     

Influence of various iodine supplementation levels and two different iodine species on the iodine content of the milk of cows fed rapeseed meal or distillers dried grains with solubles as the protein source

Supplementation of animal feed with iodine influences the iodine content of milk and therefore, in addition to salt iodination, provides another possibility for improving the human iodine supply. On the other hand, excessive iodine intake by humans through drinking milk must be avoided. Furthermore, the iodine content of milk varies, depending on the presence of iodine antagonists in feed (e.g., glucosinolates in rapeseed) and the applied iodine species. This study evaluated the impact of various feed iodine supplementation levels up to the permitted maximum level, the effect of applying rapeseed compared with a glucosinolate-free ration, and the impact of 2 different iodine species on the iodine content of milk. A total of 32 dairy cows were divided into 4 groups with 8 animals each. Two groups received distillers dried grains with solubles (DDGS) as the protein source, and the others received rapeseed meal (RSM, 16.5% of total diet). In each case, half the animals received feed supplemented with iodine in the form of potassium iodide, and the other half received feed supplemented with iodine in the form of calcium iodate. Iodine supplementation levels of 0, 0.5, 1, 2, 3, 4, and 5 mg/kg of dry matter (DM) were tested in consecutive periods of 21 d each. The milk iodine concentration increased with increasing iodine supplementation of the feed. Rapeseed meal in the ration (0.58 mmol of glucosinolates/kg of diet DM) diminished the milk iodine concentration by up to one-half to one-third of the concentration achieved by DDGS. At iodine supplementation levels of 2 mg/kg of DM and higher, the differences were significant. The application of iodate predominantly resulted in higher milk iodine concentrations compared with iodide, but not significantly in any period. At the highest tested iodine supplementation (5 mg/kg of DM), the milk iodine concentration increased up to 1,464 (iodide) and 1,578 μg/kg (iodate) when feeding DDGS and up to 718 (iodide) and 620 μg/kg (iodate) in the RSM groups. The carry over of iodine from feed into milk amounted to 30 to 56% when using DDGS, and 11 to 25% when using RSM. The maximum level of iodine currently allowed in the feed of dairy cows in Europe could lead to high milk iodine concentrations. As a result, the Tolerable Upper Intake Level in human nutrition could be exceeded. Therefore, this maximum level needs to be reevaluated. In addition to iodine supplementation, the application of RSM in the ration must be considered when estimating the iodine content of milk.     

芽孢杆菌配伍发酵菜籽粕产中性蛋白酶条件研究

为了提高中性蛋白酶的产量,采用响应曲面法研究了微生物配伍发酵菜籽粕产中性蛋白酶的条件。确定了微生物配伍菌种为Bacillus subtilis UV-7+UN-11（1∶1）;在单因素实验基础上,以中性蛋白酶活力为指标,进行BoxBehnken设计,获得最佳发酵条件为:发酵温度35.7℃,转速193r/min,接种量为7.58%,该条件下中性蛋白酶活力的理论值为2709.9U/m L,在最佳条件下进行3次验证,中性蛋白酶活力为（2714.5±2.4）U/m L,与理论预测值基本一致,比未优化前的2602.7U/m L提高了4.3%。      

Effects of dietary rumen‐protected lysine on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal

This study investigated the effects of dietary rumen‐protected lysine (RPLys) on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal. Twenty‐four cows were divided into three groups and fed one of three dietary treatments: 10% soya bean meal (SBM) diet (control), 15% double‐low rapeseed meal (DLRSM) diet and 15% DLRSM + 32 g/d RPLys (DLRSML) diet. The results showed that no differences (P > 0.05) were observed in milk yield, 4% fat correction milk (FCM), energy correction milk (ECM), protein yield, milk fat yield, milk fat, lactose yield and lactose between control and DLRSM. Supplementation with DLRSML increased (P < 0.05) milk yield, 4% FCM, ECM, and protein yield compared with the SBM. The results indicated that DLRSM and DLRSML might be used to substitute for SBM as a protein source in lactating cows, and the latter might be more beneficial to improve the performance.     

The effects of early post-mortem pH and ultimate pH on level and amount of destructured zones in cooked cured hams

Effects of early (1 h p.m. and 3 h p.m.) and ultimate pH (24 h p.m.) on level and amount of destructured zones in cooked cured hams were evaluated. In experiment 1, electrically stimulated (50 V, 14 Hz, 2 × 90 s) and non-stimulated carcass halves, both in combination with two cooling procedures (2 °C from 30 min p.m. vs. 120 min p.m.) resulted in 1.5–35.2 g/kg destructured zones in silversides and 58.4–120.0 g/kg destructured zones in topsides. A high temperature 1 h p.m. in silversides (P = 0.067) and topsides (P = 0.054) was identified as the most important predictor for the defect. In experiment 2, cooked cured hams from topsides selected according to ultimate pH groups (pH < 5.5, pH 5.5–5.7, pH > 5.7) showed between 12.3 and 61.8 g/kg destructured zones. Ultimate pH was specified as most important, however, statistically still not significant (P = 0.135) predictor for the defect. Chemical analysis resulted in low crude ash and high dry matter content as being characteristic for the defect.     

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。     

超临界CO2萃取双低油菜籽中油脂及其品质研究

为解决双低菜籽优质后的优用问题,提高双低菜籽油和饼粕的副加值,采用超临界CO_2萃取双低油菜籽中油脂,并对该工艺得到的油和脱脂菜粕品质进行了研究。通过单因素试验研究了萃取压力、萃取温度、萃取时间,萃取流量和原料粒径对油脂提取率的影响。根据单因素试验的结果设计四因素三水平的正交试验得最优工艺参数:萃取温度35℃、压力30 MPa、时间120 min,原料粒度80目,在此条件下油脂提取率可达97.15%。经超临界CO_2萃取得到的双低菜籽油色泽浅,酸价与过氧化值都优于正已烷工艺,磷脂含量0.021 mg/g,为正已烷工艺的3.82%;维生素E含量17.26μg/g约是正已烷工艺的2倍,总酚与甾醇含量比正已烷工艺略低。采用超临界CO_2萃取得到的"双低"菜粕植酸含量低,蛋白溶解度高,颜色浅,其品质明显优于正已烷萃取的脱脂粕。研究结果可为双低油菜的高值化利用提供数据参考。     

双酶水解菜籽粕及水解物的抗氧化活性研究

中性蛋白酶分别与alcalase,protamex,flavourzyme,木瓜蛋白酶及胰蛋白酶相结合,用双酶相继水解菜籽粕,得到5组菜籽粕的双酶水解物。双酶水解物抗氧化活性试验结果表明,所有水解物都具有一定清除DPPH自由基活性的能力、还原能力和抑制亚油酸氧化活性的能力,但以中性蛋白酶和胰蛋白酶组合的水解物最强。该水解物的凝胶层析分离结果表明,4组分离物中分子量为6500-1050Da的组分清除DPPH自由基的活性最高,显示菜籽粕双酶水解物的抗氧化活性取决于水解物的分子结构,即不仅与酶的种类有关,还与水解条件和水解度有关。     

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.     

Production of toxic glucosinolate derivatives from rapeseed meal by intestinal microflora of rat and chicken

This work was based on a comparison between rats and chickens with different bacteriological status and fed rapeseed meal diets (DARMOR 00,39·0 % and 32·8%, respectively). Results obtained with conventional vs axenic animals show that the rat intestinal microflora is responsible for the dramatic growth depression and for the slight hypertrophy of glucosinolate target organs (thyroid, liver, kidneys). Only a strong goitrogenic effect is seen with young conventional birds. Chimera animal models (axenic animals inoculated with the whole faecal flora of another animal species) prove that the nature of the recipient host (rat) does not influence the expression of chicken intestinal microjlora in our experimental conditions. The rat whole faecal flora does not interfere with chicken growth rate, and thyroid hypertrophy is very moderate compared with conventional birds. Finally, of the two molecules responsible for the goitrogenicity, one is destroyed by the feed irradiation required for axenic experiments.     

响应面法优化油菜籽粕中硫苷酶解工艺及其降解产物抑菌作用的初步研究

以油菜籽粕为原料,在单因素实验基础上,选取酶解缓冲液p H、酶解温度和酶解时间为自变量,以酶解产物异硫氰酸酯含量为响应值,利用Box-Behnken中心组合设计原理和响应面分析法,研究各自变量的交互作用对异硫氰酸酯含量的影响,建立异硫氰酸酯含量的二次回归方程,并通过抑菌圈实验,分析了异硫氰酸酯对哈密瓜采后两种常见病原菌的抑制作用。结果表明:酶解缓冲液p H3.70、酶解温度45℃、酶解时间96 min,在此最优条件下异硫氰酸酯含量为3.005%。抑菌实验表明,异硫氰酸酯对镰刀菌和链格孢菌有明显的抑制作用。      

菜籽饼粕中硫甙及其降解物分析中存在的问题

阐述了菜籽饼粕中硫甙的降解途径和各种毒素的存在形式,并指出目前分析测定硫甙、噁唑烷硫酮、异硫氰酸酯、腈类和硫氰酸酯等毒素中存在的一些问题,以期为今后的研究提供参考。