复原乳中营养成分比例对酸奶品质的影响

Effects of different ratio ingredients in reconstituted milk on yogurt quality

为了探究同一体系中复原乳营养成分比例不同对酸奶发酵速度和质量品质的影响。以脱脂乳粉为对照组,通过成分添加改变体系比例,测定乳糖、脂肪、酪蛋白和乳清蛋白的含量。在此基础上测定发酵后酸奶的酸度、持水力、粘度、pH等特性,并对其进行感官评定和正交试验的优化。结果表明,最佳发酵时间表现为6 h,乳糖和蛋白质的增加对酸奶发酵速度均有提高,其中乳糖调节更加稳定,乳糖含量为5.10%时6 h发酵后酸度就可达到79.2°T,脂肪对酸度几乎无影响。乳糖和酪蛋白增加对酸奶酸度和持水能力有一定的增强作用,乳清蛋白对酸奶质构影响明显,脂肪对酸奶风味和持水能力影响最大,并能明显改善酸奶色泽。最后通过感官评价结果进行正交试验优化,得出体系中最佳营养成分比例为乳糖含量8.88%、脂肪含量1.98%、酪蛋白含量4.94%、乳清蛋白含量为3.57%时产品最受喜爱。

The effects of different proportions of milk powder nutrients on the fermentation speed and quality of yogurt in the same system were explored.Taking skimmed milk powder as a control group,the contents of lactose,fat,casein and whey protein were determined by adding ingredients to change the system ratio.On this basis,the acidity,water holding capacity,viscosity,pH and other characteristics of yogurt after fermentation were measured,and sensory evaluation and orthogonal test optimization were carried out.The results showed that the optimal fermentation time was 6 h,the increase of lactose and protein increased the fermentation speed of yogurt,and the lactose adjustment was more stable.When the lactose content was 5.10%,the acidity could reach 79.2°T after 6 h fermentation.Fat had little effect on acidity.The increased lactose and casein had certain enhancement effects on the acidity and water holding capacity of yogurt.Whey protein had a significant effect on the texture of yogurt;fat has the greatest influence on the flavor and water holding capacity of yogurt,and could significantly improve the color of yogurt.Finally,the orthogonal test was optimized through the sensory evaluation results,and it was found that the optimal nutrient ratios in the system were as follows:medium lactose content 8.88%,fat content 1.98%,casein content 4.94%and whey protein content 3.57%.