乳清蛋白-黄油乳液凝胶对低脂酸奶理化特性及品质的影响

乳液凝胶是一种新型的脂肪替代物,乳清蛋白和黄油是乳品中常用的原、辅料,利用乳清蛋白和黄油制作的乳液凝胶在乳制品加工中具有良好的应用前景。制备不同蛋白和脂肪含量的乳清蛋白-黄油乳液凝胶颗粒(whey protein-butter emulsion gel particles,WPI-EG),研究其对低脂酸奶理化特性及感官品质的影响,通过分析酸奶的持水力、质构、流变、微观结构及感官评价等指标,评价WPI-EG在低脂酸奶中的作用。结果表明,WPI-EG(5.5%蛋白质,7.9%脂肪)改善了酸奶的质构特性,硬度、稠度、黏聚性及胶着度显著增加,持水力增强。添加WPI-EG的实验组低脂酸奶的表观黏度显著高于对照组低脂酸奶。电镜结果显示,随着添加的WPI-EG中蛋白质和脂肪质量分数的增加,酸奶网络结构更加紧密。5.5%PR感官评价得分较高,具有较好的香气、润滑感和组织状态(酸奶中的WPI-EG添加量为10.9%)。研究显示,特定蛋白和脂肪含量的WPI-EG在酸奶中能够作为脂肪替代物和稳定剂,显著提升低脂酸奶的品质。

Effect of whey protein emulsion gel on the physicochemical properties and quality of low-fat yoghurt

Emulsion gel is a new type of fat replacer.Whey protein and butter are commonly used in dairy products and whey protein-butter emulsion gel could be used as potential fat replacer in dairy industry.In this study,whey protein-butter emulsion gel particles(WPI-EG)with different protein and fat contents were prepared,and their effects on the water holding capacity(WHC),texture,rheology,microstructure and sensory evaluation of low-fat yoghurt were studied.The results showed that WPI-EG(5.5%mass fraction of protein and 7.9%mass fraction of fat)improved the texture properties of yoghurt.The hardness,consistency,cohesiveness and adhesiveness were significantly increased,and WHC was also improved.The apparent viscosity of the low-fat yoghurt added with WPI-EG was significantly higher than that of the control group.Microstructure showed that with the increase of protein and fat contents in WPI-EG,the yoghurt had a more compact network structure and smaller pores.The growp with 5.5%of protein had a higher sensory evaluation score.It had a better aroma,lubrication and tissue state(WPI-EG in yoghurt was 10.9%of mass fraction)compared with other samples adding WPI-EG.This study showed that WPI-EG with specific protein and fat content can be used as fat replacer and stabilizer in yoghurt.WPI-EG can significantly improve the quality of low-fat yoghurt.