不同热处理液态牛乳产品中主要活性蛋白质量浓度差异研究

Study on Mass Concentration Variation of Main Active Proteins in Different Heat-treated Liquid Bovine Milk Products

为了建立RP-HPLC方法快速准确测定不同热处理方式的市售液态牛乳中主要活性蛋白包括α-乳白蛋白(α-La)和β-乳球蛋白(β-Lg)的质量浓度,建立了测定活性乳蛋白所使用的RP-HPLC法,该法具有良好的稳定性(RSD<8%)和较高的回收率(>95%)。测定结果表明,与原料乳相比,经过高温处理(常温存放)的液态乳中的活性α-La和β-Lg显著偏低(<0.16 g/L);而经巴氏杀菌后低温存放(2~6℃)的液态乳样品中活性乳蛋白可得到很好地保持,部分灭菌后低温存放的样品中活性蛋白损失较大。本研究旨为优化液态乳热处理工艺和规范乳企业对于液态乳的工业生产提供借鉴,为消费者对液态乳制品的选择提供指导。

In order to establish the RP-HPLC method to quickly and accurately evaluate the mass concentrations of the main active proteins includingα-lactalbumin(α-La)andβ-lactoglobulin(β-Lg)in the commercial liquid milk products processed by different heat treatment,RP-HPLC method had been used to determine the active milk proteins with good stability(RSD<8%)and high recovery rate(>95%).The sample measurement results showed that compared with the raw milk,the mass concentrations of activeα-La andβ-Lg in the liquid milk after high temperature treatment(products stored at room temperature)are significantly lower(<0.16 g/L);while as to the pasteurized milk stored at low temperature(2-6℃),the active milk proteins in most of the milk samples could be well maintained,but some samples which were stored at low temperature after sterilization lost more active proteins.This study could provide reference for optimizing the heat treatment process of liquid milk and standardizing the industrial production of liquid milk by dairy companies,and this would be of great guiding significance for consumers to choose liquid dairy products.