蛋白水解物对DNA和红细胞氧化损伤的保护作用

目的:研究鹿茸蛋白和大豆分离蛋白水解物对DNA和红细胞氧化损伤的保护作用。方法:以H2O2和AAPH诱导DNA和红细胞氧化损伤,采用DNA琼脂糖凝胶电泳和分光光度法分别评价蛋白水解物对DNA氧化损伤和红细胞溶血的影响。结果:鹿茸蛋白模拟胃肠消化物,鹿茸蛋白碱性蛋白酶水解物,大豆分离蛋白模拟胃肠消化物和大豆分离蛋白碱性蛋白酶水解物对H2O2和AAPH诱导的DNA和红细胞氧化损伤均具有保护作用。综合分析结果:大豆分离蛋白模拟胃肠消化物的抗氧化作用最强,抑制H2O2和AAPH诱导的DNA氧化损伤和红细胞溶血的IC50值分别为10.5,1.4,3.5 mg/m L和2.2 mg/m L。结论:大豆分离蛋白模拟胃肠消化物具有良好的抗氧化作用,能保护离体DNA和红细胞免受自由基诱导的氧化损伤,将其用于功能性食品和保健品具有较好的开发和应用价值。     

鹿茸水提取物及其蛋白酶解物对小鼠脾淋巴细胞增殖的影响

研究了鹿茸水提取物中非蛋白成分、粗蛋白酶解物及分离组分对小鼠脾淋巴细胞增殖的影响.非蛋白成分和酶解物的分离分别采用HPLC法和超滤法.应用WST-8法检测各分离组分对小鼠脾淋巴细胞增殖的影响,采用高分辨质谱对非蛋白成分进行初步鉴定.结果显示,非蛋白成分对未经刀豆蛋白A(ConA)诱导的小鼠脾细胞增殖的促进作用优于其分离...     

蛋白酶水解大豆分离蛋白的分子水平表征

采用两种蛋白酶(胃蛋白酶和碱性蛋白酶)对大豆分离蛋白进行水解,水解结束调节pH至4.8,离心分离得到酸可溶蛋白和酸不可溶蛋白.考察不同的蛋白酶、水解时间、温度以及未添加蛋白酶的情况下,酸不可溶蛋白所占比例,并采用SE-HPLC和SDS-PAGE对这些酶解物进行了分子水平的表征.结果发现:胃蛋白酶选择性地水解大豆球蛋白(11S),在pH 2.0、37℃条件下水解6h,酸不可溶蛋白所占比例为51.14％,其相对分子质量大于10 kDa的部分占到50％以上.水解温度对碱性蛋白酶水解大豆分离蛋白的影响较大,在pH 8.0、60℃条件下水解1h获得的大豆分离蛋白碱性蛋白酶酶解物的相对分子质量主要分布在20 kDa以下.不同蛋白酶水解大豆分离蛋白,其水解进程存在显著差异,即使是采用同一种蛋白酶进行水解,不同的水解条件下得到的酶解物分子结构也大不相同.     

碱性蛋白酶和木瓜蛋白酶对热变性大豆分离蛋白的酶解研究

采用碱性蛋白酶和木瓜蛋白酶对热变性大豆分离蛋白进行酶解,研究两种蛋白酶酶解温度对大豆分离蛋白酶解效果的影响。结果表明:碱性蛋白酶在60℃时比在70℃时对大豆分离蛋白的酶解更彻底,得到的相对分子质量小的肽段更多,大豆分离蛋白的水解度较高(14.73%);酶解温度对木瓜蛋白酶酶解大豆分离蛋白的效果影响不明显;与木瓜蛋白酶相比,碱性蛋白酶酶解大豆分离蛋白可以得到更多的小分子肽段。     

源于地龙蛋白的抗氧化肽鉴定与构效关系

为探究外源蛋白酶预酶解处理对地龙蛋白胃肠消化程度和胃肠消化后抗氧化活性的影响。该研究利用五种蛋白酶制备了不同的地龙蛋白酶解物,然后通过体外胃肠模拟消化探究这些酶解物的水解度、分子量分布和体外抗氧化活性的变化。五种蛋白酶酶解物中,碱性蛋白酶酶解物的水解度最高,为40.8%,其对DPPH、ABTS自由基的清除能力分别为27.36、175.46 μmol TE/g,ORAC值为0.70 μmol TE/mg。碱性蛋白酶酶解物经胃肠消化后的水解度、DPPH自由基清除率、ORAC值相比于地龙蛋白直接胃肠消化所得产物（EWP）分别提高了94.06%、72.21%及120.00%。GHEWP中鉴定出10 823条分子量<3 ku的肽,通过bioware.ucd.ie进行活性阈值评分筛选出活性评分最高的11个肽进行合成,验证活性,其中ATSGFFVY、HCFVLY、HLASGWY、HRYSDF、HYANMY的综合抗氧化能力较好,量子化学计算结果表明：ATSGFFVY、HCFVLY、HRYSDF、HYANMY的活性位点可能分别位于Tyr-8、Tyr-6、Tyr-3、Tyr-2上;HLASGWY的活性位点可能位于Trp-6上。该研究表明碱性蛋白酶预酶解可提高地龙蛋白的消化程度,增强其胃肠消化产物的抗氧化活性。     

大豆球蛋白酶解物清除DPPH自由基活性的研究

以7S和11S大豆球蛋白为原料,用Alcalase碱性蛋白酶、Neutrase中性蛋白酶、胰蛋白酶、木瓜蛋白酶、菠萝蛋白酶制备大豆球蛋白酶解产物,分别测定其DPPH(1,1-二苯基苦酰基苯肼)自由基清除活力和水解度,从5种蛋白酶中筛选出碱性内切蛋白酶酶解物的清除活力最高,且相同水解时间的水解度最大.选择碱性蛋白酶为最佳水解酶,利用正交试验优化了其最佳水解条件,碱性内切蛋白酶水解7S和11S大豆球蛋白的最佳条件为:温度55℃,pH 8.0,酶用量5%,底物浓度4%.结果表明:在最佳水解条件下,7S大豆球蛋白酶解物的DPPH自由基清除活力比11S大豆球蛋白酶解物的高.     

小麦蛋白Alcalase水解物免疫活性肽的研究

实验研究了以Alcalase碱性蛋白酶水解小麦分离蛋白制备小麦肽的工艺，分析了温度、pH值、底物浓度、酶添加量和时间对酶水解的影响。通过正交实验得到了Alcalase水解小麦蛋白的最佳工艺，工艺参数为酶用量22．5μL／g，pH值9．5，温度60℃，底物浓度4％，反应时间100min，水解度18．63％。所得小麦肽混合物用离子交换树脂依据电荷进行初步分离获得4个组分。经过小鼠体外脾淋巴细胞增殖反应（MTT法）鉴定其免疫活性，结果表明pH8和pH10洗脱得到的组分对小鼠脾细胞增殖具有较强的刺激作用，组分中可能含有对小鼠体外淋巴细胞增殖具有刺激作用的活性肽。     

大豆分离蛋白重组蛋白酶水解肽对小鼠免疫功能及抗氧化能力的影响

为了研究重组酱油曲霉碱性蛋白酶(rAp)水解大豆分离蛋白获得的大豆肽对小鼠免疫功能及抗氧化能力的影响,将诱导表达后分离纯化的rAp对大豆分离蛋白进行水解,然后将水解液灌胃小白鼠,测定其水解液对小鼠免疫器官指数、小鼠血清溶菌酶活性和小鼠血清抗菌活力等对小鼠免疫功能的影响;通过测定谷胱甘肽过氧化物酶(GSH-PX)和过氧化...     

鹿茸水提物模拟胃肠消化物对小鼠脾细胞增殖的影响

研究鹿茸水提取物模拟胃肠消化物(AEVA-SGD)的分离组分对小鼠脾淋巴细胞增殖的影响。AEVA-SGD的分离采用凝胶层析法和RP-HPLC法。应用WST-8法检测各分离组分对小鼠脾淋巴细胞增殖的影响,采用高分辨质谱对有效分离组分进行初步鉴定。结果显示,AEVA-SGD经Sephadex LH-20分离后得到6个组分(A～F)。其中,组分F对小鼠脾细胞增殖的影响最为显著,可单独促进小鼠脾细胞增殖,但对ConA诱导的T淋巴细胞增殖有抑制作用。经RP-HPLC将组分F分为3个部分,初步鉴定组分F1为鸟嘌呤,F2为1-甲基鸟嘌呤和黄嘌呤,F3为多种小肽的混合物。组分F3对小鼠脾细胞增殖的影响最大,组分F对小鼠脾细胞增殖的影响是其各分离组分协同作用的结果。     

具有金属螯合活性的蚕豆蛋白酶解物的制备

目的探究蚕豆蛋白酶解物的金属螯合活性,研究其金属螯合活性与其抗氧化活性的关系。方法分别采用碱性蛋白酶、中性蛋白酶、木瓜蛋白酶对蚕豆蛋白进行酶解,并测定其水解物的抗氧化活性与金属螯合活性,选用碱性蛋白酶为酶解蚕豆蛋白制取金属螯合肽的最适酶,以酶解产物的水解度、抗氧化活性及金属螯合活性为测定指标获得合适的水解条件。结果 3种蛋白酶的蚕豆蛋白酶解产物都有金属螯合活性和抗氧化活性,碱性蛋白酶为酶解蚕豆蛋白的最适酶,最适酶解时间为4 h时,得到的酶解产物金属离子螯合率为88.22%,抑制羟自由基能力为220.70 U/mg,总还原力为0.03 U/mg。结论蚕豆蛋白酶解物具有一定的金属离子螯合活性与抗氧化活性,水解度对蚕豆蛋白酶解物的金属离子螯合活性及抗氧化活性有明显的影响,蚕豆蛋白酶解物的金属螯合活性与总还原力及抑制羟自由基能力呈现显著的正相关性,相关系数分别为0.925、0.968(P0.01)。     

Probiotics and prebiotics--perspectives and challenges

Owing to their health benefits, probiotics and prebiotics are nowadays widely used in yogurts and fermented milks, which are leader products of functional foods worldwide. The world market for functional foods has grown rapidly in the last three decades, with an estimated size in 2003 of ca US$ 33 billion, while the European market estimation exceeded US$ 2 billion in the same year. However, the production of probiotics and prebiotics at industrial scale faces several challenges, including the search for economical and abundant raw materials for prebiotic production, the low-cost production of probiotics and the improvement of probiotic viability after storage or during the manufacturing process of the functional food. In this review, functional foods based on probiotics and prebiotics are introduced as a key biotechnological field with tremendous potential for innovation. A concise state of the art addressing the fundamentals and challenges for the development of new probiotic- and prebiotic-based foods is presented, the niches for future research being clearly identified and discussed.     

常用消毒灭菌法及其机理与应用

介绍了采用消毒灭菌方法,有加热消毒法,紫外线辐射法和化学药剂消毒法。常用化学药剂有醛类、含氯消毒剂、醇类消毒剂以及高锰酸钾、生石灰等,阐释了消毒与灭菌两个概念的区别。     

European citizen and consumer attitudes and preferences regarding beef and pork

This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries.     

毛霉型低盐速成豆豉工业化生产工艺与设备

本文介绍了毛霉型低盐速成豆豉的工业化生产工艺及生产线的关键设备。     

原花色素及其开发应用

对原花色素的结构、化学特性、制备、分析方法、应用前景作一综述,并重点讨论其生理功能,为在功能性食品、药物、化妆品等领域的深入研究和开发提供参考。     

益生素、益生菌与结肠癌

介绍了益生素和益生菌及其作用机理。在动物模型中，有大量的数据证实益生素和益生菌能够预防癌症．而在人体内还没有直接实验证据。它们抑制癌症的确切机理目前尚不清楚，其抑制机理可能是：肠道菌群代谢活动的改变，肠道理化环境的改变，潜在的致癌物质的黏附和降解，肠道菌群的改变、抗癌或抗诱变物质的形成、提高宿主的免疫应答、影响宿主的生理活动以及发酵不能被消化的食物并形成有益代谢产物。     

组学技术与果蔬采后质量和安全控制

果蔬可以提供营养, 有利于人类健康, 而果蔬的后熟及其与环境的相互作用会影响果蔬采后的质量和安全。对果蔬生物学过程的了解和掌握是减少果蔬采后损失和保障果蔬采后质量和安全的关键。在过去的10多年, 基于组学技术的系统生物学在了解果蔬后熟及其与环境相互作用的分子机制方面得到了越来越多的应用。本文对此做了细致的总结, 指出了存在的不足, 并提出了未来的发展方向。     

天然香精香料与生物技术

天然香精香料是高价值的精细化工产品和食品添加剂,但原料来源有限且提取成本高。利用生物技术生产这类产品具有广阔的前景。简述了发酵工程、酶工程、细胞工程和基因工程在香精香料中的应用,并探讨了生物技术在香精香料中的应用前景。     

节能节水型印染助剂和设备的现状

从节能、节水、缩短工艺流程和环保的角度出发,介绍了国内外研制开发的一系列新型节能、节水型印染助剂和染整设备。     

Heritability and correlations for body condition score and dairy form within and across lactation and age

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.