乳清蛋白粉对凝固型酸奶品质的影响

为提高凝固型酸奶的品质及安全性,将1%、1.5%、2%、2.5%、3%、4%、5%乳清蛋白粉(Whey protein powder,WPP)加入全脂乳粉中生产酸奶,以不添加WPP的凝固型酸奶为对照组,测定酸奶酸度、持水力(WHC)、脱水收缩敏感性(STS)、质构特性、流变学特性和微观结构变化,并进行感官评定,研究不同添加量乳清蛋白粉对凝固型酸奶品质特性的影响,以确定WPP最适添加量。结果表明:随着乳清蛋白粉添加量的增加,酸奶的滴定酸度、持水力、乳酸菌总数、硬度、胶着性、粘弹性、凝胶性逐渐增加,脱水收缩敏感性(STS)逐渐减小;当WPP添加量为2%时,酸奶的持水力、粘弹性都明显提升,STS明显降低,且具有较好的口感、更连续的网络结构,与对照组相比综合品质得到明显提高。

Effect of Whey Protein Powder on the Quality of Solidified Yogurt

In order to improve the quality and safety of the solidified yoghurt, 1%, 1.5%, 2%, 2.5%, 3%, 4%, 5% whey protein powder (WPP) was added to the whole milk powder.In the production of yoghurt, the coagulation yoghurt without WPP was used as a control group, and the acidity, water holding capacity (WHC), syneresis sensitivity (STS), texture characteristics, rheological properties and microstructure changes of the yoghurt were measured and sensed.The effect of different amounts of whey protein powder on the quality characteristics of solidified yogurt was evaluated to determine the optimum amount of WPP. The results showed that, with the increase of the amount of whey protein powder, the titration acidity, water holding capacity, total number of lactic acid bacteria, hardness, adhesiveness, viscoelasticity and gelation of yogurt increased gradually, and the syneresis sensitivity (STS) decreased gradually. When the amount of WPP was 2%, the water holding capacity and viscoelasticity of yogurt significantly increased, the STS significantly reduced, and it had a better taste and a more continuous network structure. Compared with the control group, the overall quality was significantly improved.