降血压奶粉的开发与研制

研究了如何利用牛资源、采用酶水解方法、通过对酪蛋白或乳清蛋白进行酶水解，得到具有生物活性并能降低血压的肽——降血压肽，并将其同奶粉结合生产出能够降低血压的奶粉。     

动植物源蛋白体外消化产物结构性质及ACE抑制活性

为揭示动植物源蛋白对于血压调节功能上的差异是否由蛋白肽的血管紧张素转化酶（angiotensin conversion enzyme,ACE）抑制活性所引起,动植物蛋白经体外消化后,对蛋白肽的ACE活性抑制进行研究。采用胃蛋白酶-胰蛋白酶两步消化法,水解植物蛋白（大米、燕麦、大豆、豌豆）、红肉蛋白（猪肉、牛肉）和白肉蛋白（鸡肉）。测定所获蛋白肽的水解度、分子质量分布、氨基酸组成及其ACE抑制率。结果表明,随着蛋白质水解度的增加和分子质量的减小,3类蛋白消化产物的ACE活性抑制率均相应增大。其中,植物蛋白消化产物ACE抑制率最高（60.41%）,红肉蛋白最低（40.13%）。对蛋白质消化产物的氨基酸组成进行分析,结果表明,植物蛋白和白肉蛋白消化产物的疏水性氨基酸含量均显著高于红肉蛋白。3类蛋白中消化产物的疏水性氨基酸含量越高,则ACE抑制活性越高,说明疏水性氨基酸含量高可能是植物蛋白肽具有高的ACE抑制活性的主要原因之一。     

肉蛋白中的衍生的生物活性肽的研究进展

生物活性肽是对生物体的生命活动有益或具有生理作用的肽类化舍物.相对于食物蛋白衍生的生物活性肽而言,肉蛋白中衍生肽的信息仍然是不充分的.本文介绍了肉蛋白中衍生的ACE抑制肽、阿片样活性肽、抗氧化活性肽,并对生物活性肽研究的前景进行了概述,以利用其发展新功能肉制品.     

酶解牛肉蛋白肽在美拉德反应中降解趋势

目的：研究牛肉蛋白肽在美拉德(Maillard)反应体系中肽的降解变化,探究肽Maillard反应体系中肉香味产物与反应物之间的对应关系。方法：分别建立牛肉酶解液及由其制得肽的Maillard反应体系以及肽的热降解反应体系;用高效尺寸排阻色谱、GC-MS方法分别对牛肉蛋白肽和Maillard反应产物进行分析。结果：牛肉蛋白酶解肽在Maillard反应之后与热降解反应之后的尺寸排阻色谱图并不相同,GC-MS方法从牛肉酶解液的Maillard反应体系中检测出36种化合物,肽的反应体系中则检测出31种。结论：牛肉蛋白肽参与Maillard反应的主体部分分子质量介于1000～2000D之间;肽参与的Maillard反应体系中,呋喃与呋喃酮类物质主要产生于糖类的热降解反应,吡嗪类物质产生于肽和木糖的反应,噻唑、噻吩类及硫醇类物质主要由硫胺素降解产生。     

牛肉酶解工艺及其产物的研究进展

常用于水解牛肉的酶有木瓜蛋白酶、动物蛋白水解复合酶、风味复合酶等,本文总结了蛋白酶水解牛肉的工艺以及酶法水解牛肉的研究现状,归纳了牛肉酶解的3种工艺方法:单酶水解、多酶复合水解和多酶分步水解。结果表明:牛肉经过酶解释放出氨基酸或形成多肽,更利于人体消化吸收,并且具有一定的生物活性,牛肉酶解工艺在肉制品行业中有广阔的发展前景。     

猪肉蛋白和牛肉蛋白对生长期大鼠生理功能的影响

目的：研究长期摄入猪肉蛋白和牛肉蛋白对生长期大鼠生长性能、生理功能的影响。方法：30 只雄性Sprague-Dawley（SD）大鼠随机分为3 组,分别饲喂添加酪蛋白、猪肉蛋白和牛肉蛋白作为蛋白质来源的半合成饲料,实验期为90 d,观察其对大鼠生理指标的影响。结果：相对于酪蛋白组,猪肉蛋白组和牛肉蛋白组大鼠的生长速率变缓,脂肪沉积减少（P＜0.05）,但有较高的谷丙转氨酶和谷草转氨酶活力（P＜0.05）。猪肉蛋白和牛肉蛋白可降低大鼠血清中的甘油三酯浓度（P＜0.05）,牛肉蛋白还可降低总胆固醇和血糖浓度（P＜0.05）,猪肉蛋白则对其没有显著影响（P＞0.05）。猪肉蛋白组和牛肉蛋白组的大鼠有较低的血清游离氨基酸水平（P＜0.05）。结论：长期摄入猪肉蛋白和牛肉蛋白会对大鼠机体代谢产生不同的影响,这与蛋白质来源及其消化和吸收有关。猪肉蛋白和牛肉蛋白有控制大鼠体质量增长的作用,牛肉蛋白还可以降低大鼠肝脏代谢水平,具有降血脂的功能。     

木瓜蛋白酶水解鸡肉蛋白及其产物氨基酸分析研究

本文采用木瓜蛋白酶水解鸡肉蛋白研究其降解规律及酶解产物氨基酸组成。研究表明:热处理鸡肉蛋白不利于酶解;整个酶解过程中,可溶性氮、氨态氮含量呈增加趋势,但4h后增势变缓,而肽含量在水解8h达到最大值;肽分子量分布图显示大部分不溶性蛋白和分子量大于10000Da肽段在酶解4h后已经变为可溶性多肽和氨基酸,分子量在5000～10000Da间肽段酶解24h后仍大量存在,分子量在3000～5000Da间以及小于3000Da的肽占总肽量比值在整个酶解过程中呈增加趋势。与原料蛋白氨基酸组成比较表明采用木瓜蛋白酶水解鸡肉蛋白能显著提高其营养价值。     

复合酶法制备鸡肉蛋白抗氧化肽模型研究

以酶解产物对O2-·的清除率为指标,分析中性蛋白酶和未瓜蛋白酶的协同作用,确定制备鸡肉蛋白抗氧化肽的最佳复合酶解工艺,并对复合酶解过程进行酶促动力学特性研究.结果表明:复合酶解制备抗氧化肽最佳工艺为两酶混合同时加入,pH6.7,温度57℃,底物浓度6.9%,时间5h,酶用量为中性蛋白酶4943u/g、木瓜蛋白酶5988u/g,该条件下鸡肉蛋白抗氧化肽对O2-·的清除率为57.50%,显著高于各单酶水解效果.在此基础上由实验数据推导出描述复合酶制备鸡肉蛋白抗氧化肽水解过程的动力学方程,为鸡肉蛋白开发抗氧化肽提供理论依据.     

不同蛋白酶水解酪蛋白类大分子底物的规律研究

近年来，已有大量具有重要生物活性的短肽通过适当的蛋白酶水解营养或贮藏蛋白释放和辨认出来。这些蛋白资源十分丰富和廉价，通过水解这些蛋白质所获得的生物活性肽不仅价格便宜、安全性好、工艺简单，而且容易进行工业化生产。为了能够获得更高的生物活性肽得率，为生产和研究提供理论依据，本文开展了酶促蛋白水解制备生物活性肽的水解条件、底物浓度和水解度之间的关系研究。结果表明：当底物达到一定的浓度时，不仅其酶促反应速度会迅速下降，酶切位点和酶解产物也有明显不同。这些结果不符合米氏方程，显然酶解蛋白类大分子底物时酶和底物之间的作用比其他底物要复杂得多。     

牛肉酶解液的特性分析

对Papain、Alaclase、Neutrase、As1.398四种蛋白酶水解牛肉制得的富含生物活性多肽、肉碱的混合液进行了感官评定和特性分析。实验发现,牛肉的木瓜蛋白酶解液感官最好。实验中研究了水解度与蛋白质提取率、L-肉碱提取率、酸溶性肽含量、多肽分子量分布之间的关系。结果表明DH=20%左右为好,此时蛋白质提取率达95%,肉碱提取率为85%,酸溶性肽含量为48.2%,多肽分子量M>10000的占11%,M<1000的占48.4%,且口味仍可接受。钙、铁促溶性实验表明,牛肉蛋白及肽对钙铁溶解度均有一定程度的促进作用,但与DH无线性关系。     

植物多肽的制备及在食品中应用的研究进展

植物功能多肽是植物来源的蛋白通过加工后形成的肽链片断,具备独特的生理功能以及较高的营养价值而在食品中得到广泛应用。植物功能多肽在制备、分离、应用与产业化方面均取得了显著进步。植物多肽的制备技术有酸碱水解法、酶水解法、微生物发酵法,其中酶解前对植物蛋白进行预处理可改善植物功能多肽。靶向酶水解法可减少或消除苦味肽的产生,解决了多肽食品应用难题;不同酶解条件得到不同类型的植物功能多肽,并具有营养、呈味、乳化等多种功能,可用于改善食品的产品品质与功能。针对近年来功能多肽在食品方面的研究新进展,综述了植物多肽的制备、脱苦技术和功能特性,并对其产业现状和前景也进行了分析和探讨。     

Food protein-derived bioactive peptides: production, processing, and potential health benefits

Bioactive peptides (BAPs), derived through enzymatic hydrolysis of food proteins, have demonstrated potential for application as health-promoting agents against numerous human health and disease conditions, including cardiovascular disease, inflammation, and cancer. The feasibility of pharmacological application of these peptides depends on absorption and bioavailability in intact forms in target tissues, which in turn depends on structure of the peptides. Therefore, production and processing of peptides based on important structure-function parameters can lead to the production of potent peptides. This article reviews the literature on BAPs with emphasis on strategic production and processing methods as well as antihypertensive, anticancer, anticalmodulin, hypocholesterolemic, and multifunctional properties of the food protein-derived peptides. It is recommended that future research efforts on BAP should be directed toward elucidation of their in vivo molecular mechanisms of action, safety at various doses, and pharmacological activity in maintaining homeostasis during aberrant health conditions in human subjects.     

乳源性生物活性肽

乳蛋白质在体内消化和食品加工过程中均会被酶促水解而产生一些对人体具有生理调节作用的肽类物质。本文主要回顾了一些乳源性活性肽的来源、功能和氨基序列。这些肽类主要包括:抗高血压肽、类吗啡活性肽、阿片拮抗肽、抗血栓肽、矿物质元素结合肽、抗菌肽、免疫活性肽、抗HIV肽等。文章还对这些活性肽的吸收和在食品、药业上的应用潜力作了简要介绍。     

食源性降血压肽制备研究进展

高血压病防治早已引起医学界重视,食源性降血压肽降压效果明显,且无毒副作用。从植物蛋白、动物蛋白及微生物代谢产物中都可提取制备降血压肽,降血压肽制备方法主要有酶解法、发酵法、自溶法及重组法等;其中,酶解法和发酵法最为常用。降血压肽分离提纯主要采用超滤、层析等方法,低成本工业化分离方法有待开发。     

Natural Antifungal Peptides/Proteins as Model for Novel Food Preservatives

A large range of ingredients for food and food products are subject to fungal contamination, which is a major cause of destruction of crops, exposure of animals and humans to invasive mycotoxins, and food spoilage. The resistance of fungal species to common preservation methods highlights the necessity of new ways to increase the shelf life of raw material for food and food products. Antimicrobial peptides and proteins (AMPs) are essential members of the immune system of most living organisms. Due to their broad range of activity and their stability to commonly used food processes, they represent promising alternatives to traditional preservatives. However, despite the growing number of reports of potential food applications of these AMPs, the number of approved peptides is low. Poor solubility, toxicity, and a time‐consuming extraction are hurdles that limit their application in food products. Thanks to a deep understanding of the key determinants of their activity, the development of optimized synthetic peptides has reduced these drawbacks. This review presents natural and synthetic antifungal peptides/proteins (AFPs), effective against food‐related fungi, with particular emphasis on AFPs from plant sources. The design of novel antifungal peptides via key elements of antifungal activity is also reviewed. The potential applications of natural and synthetic AFPs as novel antifungal food preservatives are finally discussed.     

Altering allergenicity of cow's milk by food processing for applications in infant formula

Cow's milk-based infant formulas have a long tradition in infant nutrition, although some infants are unable to use them due to presence of several known allergens. Various processing methods have been identified capable of reducing cow's milk protein allergenicity including thermal and non-thermal methods and their combinations. Heat treatment and enzymatic hydrolysis have been in production of hypoallergenic infant formulas. However, modulation of allergenic epitopes depends on the extent of heat treatment applied, which consequently may also reduce a nutritional value of these proteins. In addition, enzymatic hydrolysis may not target allergenic epitopes thus allergenicity may persist; however released peptides may have detrimental impact on taste and functional properties of final products. Modulation of allergenicity of milk proteins appears to require a concerted effort to minimize detrimental effects as clinical studies conducted on commercial hypoallergenic formulas demonstrated persistence of allergic symptoms. This article covers traditional and novel processing methods and their impact on reduction of cow's milk allergenicity in milk-based infant formulas.     

食源性DPP-IV抑制肽降血糖作用机制研究进展

随着全球糖尿病患者人数的逐年增加,传统的药物治疗方法面临严峻挑战。研究发现,饮食干预是辅助治疗糖尿病的一种有效手段。食物中的蛋白质经酶解后可产生多种生物活性肽。其中,与糖尿病防治密切相关的二肽基肽酶-IV（Dipeptidyl peptidase-IV, DPP-IV）抑制肽已从鱼类等多种食物的酶解液中被发现。海洋生物种类丰富,是制备功能性食品的重要原料来源。本文综述了食源性DPP-IV抑制肽降糖的作用机制,特别是海洋生物来源的DPP-IV抑制肽的研究进展,旨在为开发基于DPP-IV抑制肽的功能性食品提供参考。     

Antimicrobial peptides generated from milk proteins: a survey and prospects for application in the food industry. A review

Milk proteins constitute a natural reservoir of bioactive peptides with physiological and/or antimicrobial properties, the release of which requires hydrolysis of the precursor molecules by digestive proteases or by fermentation with proteolytic micro‐organisms. Depending on the digestive or microbial proteases used, an array of bioactive peptides would be released either from caseins or whey proteins, but only a small part of these peptides has so far been identified and characterised with respect to their antimicrobial activity. The antimicrobial peptides known thus far have proven to be potent inhibitors to the growth of a wide range of undesirable micro‐organisms of health or spoilage significance. Nevertheless, previous research work has largely been oriented towards their possible application in medicine, which has hindered their high potential as food‐grade biopreservatives and/or as supplements in functional foods. This review attempts to study the literature pertaining to antimicrobial peptides derived from major milk proteins (caseins, α‐lactalbumin and β‐lactoglobulin) upon hydrolysis either by digestive proteases or by fermentation with proteolytic lactic acid bacteria. Their possible application in the food industry and their mechanism of action will also be discussed. Reference antimicrobial peptides produced by living micro‐organisms as innate immune defence components against microbial infections will occasionally be invoked for comparison purposes.     

利用高分辨质谱鉴定鱼胶原蛋白粉中的 鱼源性成分

目的建立高分辨质谱鉴定鱼胶原蛋白粉中的鱼源性成分的分析方法。方法采用高分辨质谱对酶解后的胶原蛋白粉中的肽段进行全扫描分析,通过Max Quant软件分析比对,鉴定其中的成分来源。结果在市场上随机购买的四种胶原蛋白粉(肽)有三种均不同程度混有其他物种来源蛋白和其他蛋白,只有一种是纯鱼源性胶原蛋白。结论本方法对胶原蛋白中的成分来源成功进行了鉴定,为胶原蛋白的市场监督提供了高效、有力的技术支撑。