中性及酸性条件下不同来源脱脂乳粉的稳定性比较分析

Comparative analysis of stability of different sources of skimmed milk powder under neutral and acidic conditions

中文关键词:  脱脂乳粉  稳定性  乳清蛋白氮  热凝固时间  离心沉淀

英文关键词:skimmed milk powder  stability  whey protein nitrogen  heat coagulation time  centrifugal sedimentation

中文摘要:

      目的 对5种不同来源的脱脂乳粉在中性和酸性条件下的稳定性进行比较分析。方法 对不同脱脂乳粉的营养组成、乳清蛋白氮、热凝固时间、△pH、离心沉淀率等指标进行检测并进行对比。结果 5种脱脂乳粉在蛋白质、乳糖、钙等影响稳定性的成分上差异不大, 脱脂乳粉热凝固时间越长、△pH越小, 酸性乳饮料经高温热处理后离心沉淀越少, 而脱脂乳粉乳清蛋白氮越高, 中性条件下离心沉淀越少。结论 本研究对脱脂乳粉在中性和酸性条件下的稳定性评价较为科学, 对于乳清蛋白氮、热凝固时间和△pH的测定可应用于产品中脱脂乳粉的选择。

英文摘要:

      Objective To evaluate and compare the stability of five different sources of skimmed milk powders under neutral and acidic conditions. Methods Nutrient compositions, whey protein nitrogen, heat coagulation time, △pH and centrifugal sedimentation of various skimmed milk powders were determined and compared. Results Among the five kinds of skimmed milk powders, only a minor difference was found in the content of those stability-related components including protein, lactose and calcium. Longer heat coagulation time correlated well with smaller △pH as well as less centrifugal sediment in acidified milk drink under high temperature heat treatment. Besides, higher whey protein nitrogen result seemed to imply a better performance of skimmed milk powder with less centrifugal sediment in a neutral condition. Conclusion The stability of skimmed milk powder under neutral and acidic conditions can be well evaluated, and the measurement of whey protein nitrogen, heat coagulation time and △pH can be used to select skimmed milk powder products.