乳清蛋白的功能特性及应用

介绍了乳清蛋白的组成成分和功能特性；论述了乳清蛋白的生物利用价值及在运动营养、医疗保健和食品加工等方面的广阔应用前景。     

乳清产品的营养特性

<正> 乳清含有多种营养素,可增强体质,预防疾病。经过深入的研究表明,应用乳清产品制作功能性食品和药品完全具有可行性,从而能减少传染性和慢性疾病的发生。食品科学专家偏好乳清蛋白是因其具有高生物价值、优良的功能特性以及纯净口感。虽然食品制造商已经开始在开发新产品时利用乳清的营养和功能特性,但乳清和乳清成分在增强健康方面的潜力仍然有广阔的挖掘空间。乳清产品含有蛋白质、维生素、多种矿物质和其它成分(如     

乳清蛋白在发酵乳制品中的应用

乳清蛋白具有良好的功能性,被广泛应用在各种食品中。本文综述了乳清蛋白产品的组成成分和功能特性,以及乳清蛋白对发酵乳制品的风味、质构、益生菌生长及功能营养的影响。指出乳清蛋白在发酵乳制品中具有良好的适应性和广阔的应用前景。     

海藻酸钠和乳清蛋白作为益生菌包埋壁材的比较

利用海藻酸钠和乳清蛋白分别制备包埋有两歧双歧杆菌的微胶囊,测定了不同微胶囊的粒径、包埋效率、缓冲能力和外观形态,同时还考察了不同微胶囊对两歧双歧杆菌保护效果的影响。结果表明：乳清蛋白微胶囊的粒径和包埋效率均要高于海藻酸钠微胶囊,分别为202.5 μm,87.8%和118.3 μm,48.1%;虽然在高胆盐环境中两种微胶囊对两歧双歧杆菌的保护效果没有显著差别,但在低酸环境、模拟胃液和常温贮藏期中,相比于海藻酸钠微胶囊,乳清蛋白微胶囊将两歧双歧杆菌的存活量分别提高了大约5、2、0.5（lg（CFU/mL））。乳清蛋白微胶囊在pH值偏中性的环境中具有较高的缓冲能力;在外观形态上,由高浓度乳清蛋白溶液制备而来的微胶囊具有较好的呈球性和致密度,这些可能是乳清蛋白微胶囊具有较高保护效果的原因。     

食品蛋白质的功能性质（一）——乳清蛋白与酪蛋白

乳清蛋白和酪蛋白磷酸肽是极好的营养强化剂,其添加于食品中有利于人体健康.本文介绍了乳清蛋白和酪蛋白磷酸肽的功能特性及其在食品中的应用.由于其具有多种保健功能,在食品行业中其应用前景十分广泛.     

基于β-乳球蛋白配体结合特性的活性成分包埋和保护研究现状

虽然营养活性成分具有调节生理机能的功能,但环境敏感性和低溶解度限制了许多活性成分在功能食品、药品和化妆品开发中的应用。可食用载体体系的设计和研发提供了克服这些限制的可能性。阐明载体物质和活性成分间作用机制,是设计和制备非乳状液型载体体系的关键。食品蛋白由于具有高营养价值和多种功能特性,因此被广泛应用于制备载体体系。β-乳球蛋白是牛乳中主要乳清蛋白,具有多个配体结合位点,可结合脂肪酸、维生素、磷脂、多酚类化合物等多种物质。β-乳球蛋白也可同时结合叶酸、白藜芦醇和维生素E,生成蛋白质-多配体复合物。本文概述了β-乳球蛋白与不同营养活性成分间相互作用,以及生成复合物对活性成分的保护作用,讨论了天然β-乳球蛋白作为营养活性成分载体的优、缺点以及开发基于此蛋白的多活性成分载体的可能性。     

乳清蛋白及其肽制品功能特性的研究

乳清蛋白富含必需氨基酸是膳食极好的氮源。另外,乳清蛋白和其肽制品还具有许多功能特性,这些产品还具有作为功能性食品及食品功能性配料的作用。本文简述了乳清蛋白及其肽制品功能特性与人类健康的关系。     

乳清蛋白改性的研究进展

乳清蛋白具有多种功能特性,例如乳化性、成胶性和起泡性,广泛地应用于食品中.许多研究证明,通过改性可进一步改善乳清蛋白的功能特性,开发新型的功能性乳清蛋白配料,拓展其在食品工业中的应用范围.乳清蛋白的改性方法包括物理、化学和酶法改性以及相互结合的方法,选择性使用改性方法、控制反应条件可以改善所需的功能特性.通过美拉德反应对乳清蛋白的糖基化改性是一种比较新的方法,但已经成为食品中研究的热点.     

不同壁材对水酶法提取油茶籽油乳化相微胶囊的影响

以水酶法提取油茶籽油所制得的乳化相为芯材,分别以明胶-阿拉伯胶、明胶-海藻酸钠、乳清蛋白-阿拉伯胶、乳清蛋白-海藻酸钠为壁材,制备4种油茶籽油乳化相微胶囊,并分析4种微胶囊的性质。结果表明：在4种微胶囊中,以明胶-海藻酸钠为壁材制备的油茶籽油乳化相微胶囊包埋效果最好,包埋率高达93.96%;以明胶-阿拉伯胶为壁材制备的油茶籽油乳化相微胶囊具有最小的平均粒径,更好的溶解性和热稳定性,可以制备出具有更好性能的油茶籽油乳化相微胶囊产品。     

乳清蛋白的特性及应用

乳清蛋白具有一定的功能特性和生物学活性,在食品行业中应用越来越广泛。通过改性,可以显著改善乳清蛋白的功能特性,如热稳定性、热凝胶特性、乳化特性等。蛋白变性影响乳清蛋白的特性,本文论述了乳中成分和环境条件对变性的影响。乳清蛋白在食用膜、乳品检测、蛋白提纯等方面的综合利用充分体现了其在食品行业中良好的市场前景。     

超声辅助均质制备负载人参皂苷功能型Pickering乳液的工艺优化

目的 研制一种基于乳清分离蛋白和菊粉负载人参皂苷的Pickering乳液。方法 以乳清分离蛋白与菊粉复合溶液为水相,大豆油为油相,应用超声和均质处理方法制备负载人参皂苷的Pickering乳液。通过单因素试验考察乳清分离蛋白与菊粉的质量分数比、超声功率、超声时间、均质时间对人参皂苷乳液粒径的影响,利用Box-Behnken试验设计和响应面分析确定人参皂苷Pickering乳液的制备工艺。结果 对人参皂苷Pickering乳液粒径的影响程度从大到小依次为超声时间、均质时间、超声功率。优化的制备工艺参数:超声功率272.0 W、超声时间17.0 min、均质时间6.0 min,乳清分离蛋白与菊粉的质量分数比1:1.0。在优化条件下制备的人参皂苷Pickering乳液粒径最小为(318.73±1.24) nm。结论 应用超声辅助均质处理,制备基于乳清分离蛋白和菊粉负载人参皂苷的Pickering乳液工艺可行,为进一步构建人参皂苷纳米输送体系和功能食品研发奠定基础。     

乳清蛋白在食品工业中的应用

对乳清蛋白在食品中的应用进行了简要的介绍,其中对乳清蛋白的主要组分(α- 乳白蛋白、β- 乳球蛋白、乳铁蛋白等)、功能特性(成胶性,涂层性和成膜性等)、生产技术(膜分离技术、吸附分离法、亲和色谱提纯法等)及改性方法(物理改性及酶改性)做了详细的介绍,并对我国乳清蛋白的应用前景进行了展望。     

Application of Transglutaminase-Crosslinked Whey Protein/Pectin Films as Water Barrier Coatings in Fried and Baked Foods

Whey protein/pectin edible films were prepared in the presence of transglutaminase and tested as water barrier coatings of both fried doughnuts and french fries as well as of baked food like “taralli” biscuits. Our results demonstrated an undoubted effect of the produced hydrocolloidal films, known to markedly reduce water vapor permeability, in decreasing moisture loss in both doughnuts and french fries when applied before food frying. At the same time, a significant decrease in oil content was observed in the coated fried foods (about 50 % in doughnuts and 25 % in french fries) with respect to both uncoated controls and whey/soy protein-coated samples. No difference was observed between uncoated and coated both doughnuts and french fries with regard to their texture properties and as confirmed by the data from sensory evaluation tests. Furthermore, since the coating by edible films endowed with low water vapor permeability could be useful to prevent moisture absorption by baked foods, we tested the whey protein/pectin film prepared in the presence of transglutaminase, which was also used to coat taralli biscuits. The proposed methodology resulted to be effective to hinder moisture absorption by biscuits during a long storage period, keeping water content constant from 0 to 50 days, thus preventing the food matrix conversion from a glassy state to a rubbery state which is the major cause of baked food rejection by consumers.     

Physical effects upon whey protein aggregation for nano-coating production

Production of edible nanostructures constitutes a major challenge in food nanotechnology, and has attracted a great deal of interest from several research fields — including (but not limited to) food packaging. Furthermore, whey proteins are increasingly used as nutritional and functional ingredients owing to their important biological, physical and chemical functionalities. Besides their technological and functional characteristics, whey proteins are generally recognized as safe (GRAS). Denaturation and aggregation kinetics behavior of such proteins are of particular relevance toward manufacture of novel nanostructures possessing a number of potential uses. When these processes are properly engineered and controlled, whey proteins may form nanostructures useful as carriers of bioactive compounds (e.g. antimicrobials, antioxidants and nutraceuticals). This review discusses the latest advances in nano-scale phenomena involved in protein thermal aggregation aiming at formation of bio-based nano-coating networks. The extent of aggregation is dependent upon a balance between molecular interactions and environmental factors; therefore, the impact of these conditions is addressed in a critical manner. A particular emphasis is given to the effect of temperature as long as being one of the most critical variables. The application of moderate electric fields (MEF), an emergent approach, as such or combined with conventional heating is considered as it may inhibit/prevent excessive denaturation and aggregation of whey proteins — thus opening new perspectives for development of innovative protein nanostructures (i.e. nano-coatings). A better understanding of the mechanism(s) involved in whey protein denaturation and aggregation is crucial as it conveys information relevant to select methods for manipulating interactions between molecules, and thus control their functional properties in tailor-made applications in the food industry.     

Whey protein concentrate gels with honey and wheat flour

Structural and functional properties of whey protein concentrate (WPC) gels with different honey and wheat flour contents, prepared at pHs 3.75, 4.2 and 7.0, were analysed. Gel structure was observed by scanning electron microscopy. The apparent transition temperatures for protein denaturation and starch gelatinization were determined by differential scanning calorimetry. Gels were characterised through solubility assays in different extraction solutions and polyacrylamide gel electrophoresis of the soluble protein components. The firmness, elasticity, relaxation time, adhesivity and cohesiveness of gels were determined, and the water-holding capacity and superficial colour of gels were also studied. Results suggest that wheat flour could interact with whey proteins, and produces a decrease in the protein solubility of WPC gels, and in the temperature of whey protein denaturation. The effect of wheat flour on the functional properties of WPC gels was different at acidic than at neutral pH: the presence of wheat flour produced an increase in the relaxation time and in the cohesiveness of gels prepared at pH 3.75, whereas at neutral pH a decrease in both properties was observed. Honey and flour content increased the water-holding capacity and browning of WPC gels.     

Combined Effects of Proteins and Polysaccharides on Physical Properties of Whey Protein Concentrate-based Edible Films

ABSTRACT: The water-vapor permeability (WVP) and mechanical properties of edible films formed from dry blends or co-dried preparations of protein-polysaccharide powders prepared from whey protein concentrate (WPC)-45 and alginate, pectin, carrageenan, or konjac flour (WPC-45-to-polysaccharide ratio of 95:5 w/w) were investigated. Films were prepared from 8% WPC using WPC-45 (45% protein powder), consisting of 17.76 g of WPC-45 in 82.84 g of water per 100 g solution to give 8% protein w/w. Films formed from co-dried powders had lower WVP and higher tensile strength (TS), elastic modulus (EM) ( P < 0.05), and elongation (EL) than equivalent films formed from the dry blended powders. Films containing alginate had lower WVP and higher TS, EM, and EL than films containing pectin, carrageenan, or konjac flour. There is potential to alter the physical properties of hydrophilic films by combining whey protein and polysaccharide components.     

蛋白含量对牦牛乳清蛋白浓缩物功能特性的影响

通过不同截留分子质量的再生纤维素膜过滤纯化牦牛原乳清液和牦牛甜乳清液,分别制取牦牛原乳清蛋白浓缩物（native whey protein concentrate,NWPC）和牦牛甜乳清蛋白浓缩物（sweet whey protein concentrate,SWPC）,研究蛋白含量不同的乳清蛋白浓缩物（whey protein concentrate,WPC）主要成分（乳糖含量、pH值和总蛋白质含量）和功能特性（溶解性、持水性、持油性、起泡性、乳化性及热稳定性）的特征。结果表明：10 000 Da再生纤维素膜透析得到的牦牛WPC中总蛋白含量达到80%以上,不含乳糖,功能特性（溶解性、持水性、持油性、起泡性、乳化性及热稳定性）均显著高于经3 500 Da卷式膜、5 000 Da再生纤维素膜透析得牦牛WPC,WPC蛋白含量越高,其功能特性越好;不同蛋白含量的牦牛SWPC起泡能力、泡沫稳定性、乳化活性和乳化稳定性均显著（P＜0.05）高于牦牛NWPC。牦牛乳WPC最不稳定温度为85 ℃,高于荷斯坦牛乳WPC的80 ℃,热处理会适当改善牦牛WPC的起泡性能、乳化性能和热稳定性。通过膜牦牛处理获取的高蛋白含量的WPC,功能特性较好,应用广泛,对解决牦牛乳清资源的利用问题、保护环境、提高企业的经济效益起到关键性作用。     

含微米颗粒的乳清蛋白复合膜物理性质的研究

乳清蛋白具有一定的营养价值和良好的凝聚造粒及成膜性能。使用喷雾干燥技术制备乳清蛋白微米颗粒,并将上述颗粒以1.0%、1.7%、2.5% 及3.3% 的质量分数添加到乳清蛋白成膜液中,制备含微粒的乳清蛋白复合膜。利用质构仪、扫描电镜(SEM)及差示热量扫描仪(DSC)测定颗粒对乳清蛋白膜性能的影响。结果表明,在上述实验浓度范围内,加入的颗粒对乳清蛋白膜的机械性能、水蒸气透过率、透明度及透光率值、膜的玻璃化温度及熔点均未产生显著影响,乳清蛋白基础膜的性能得到很好的保持。     

Assessment of Added Protein/Starch on the Functional Properties of Surimi Gels Manufactured from Atlantic Whiting

ABSTRACT: The functional properties (hardness, cohesiveness, color, and whiteness) of 5 food ingredients (2 whey protein concentrates [WPC 45 and WPC 76], whey protein isolate [WPI], egg white [EW], and potato starch [PS]) added to surimi gels were evaluated using 2 different thermal regimes. Hardness and cohesiveness of whiting surimi gels prepared using a rapid cook treatment (90°C for 15 min) did not significantly change on the addition of test ingredients. Hardness and cohesiveness of whiting surimi with added ingredients prepared using a suwari set treatment (0° to 4 °C for 12 h followed by 90°C for 15 min) were increased ( P < 0.05) on addition of additives with the exception of WPC 76, which decreased ( P < 0.05) surimi hardness and cohesiveness. Results showed that starch was more effective in improving the functional properties of surimi when compared with all other protein additives assessed.