改性乳清蛋白对凝固型酸奶品质及胆酸盐结合能力的影响

Effects of Modified Whey Protein on Quality and Cholate Binding Ability of Set Yoghurt

本研究利用酶结合苹果酸复合改性乳清蛋白(WPI-E+MA),添加至凝固型酸奶,以期改良凝固型酸奶质构及胆盐结合能力。通过蛋白质浓度、持水力、游离巯基、粒径、粘弹性及胆酸盐结合能力等指标,评价WPIE+MA对凝固型酸奶品质、凝胶结构及胆酸盐结合能力的影响。结果表明,WPI-E+MA能够改善凝固型酸奶的持水力、表观粘度、剪切应力与粘弹性,8%添加量时达到最优;酸奶的凝胶网状交联结构因WPI-E+MA的添加变得更加致密、聚合度更高。脱氧胆酸钠(SDC)、胆酸钠(SC)、牛磺胆酸钠(STC)结合率均在8%的添加量达到最大值,结合能力良好。WPI-E+MA可有效改善凝固型凝固型酸奶的品质并显著提高胆酸盐结合能力。

In this study,whey protein(WPI-E+MA)modified with enzyme combined malic acid was added to set yoghurt in order to improve the texture and bile salt-binding ability.The effects of WPI-E+MA on quality,gel structure and cholate binding ability of set yoghurt were evaluated.The results showed that WPI-E+MA could improve the water holding capacity,apparent viscosity,shear stress and viscoelasticity of set yoghurt.And the optimal value was obtained at the addition amount of 8%.Besides,the gel mesh crosslinked structure of yogurt became more denser and had higher degree of polymerization with the addition of WPI-E+MA.The binding rate of sodium deoxycholate(SDC),sodium cholate(SC)and sodium taurocholate(STC)also reached the maximum value at 8%.WPI-E+MA could effectively improve the quality of set yoghurt and enhance the cholate binding ability.