家用冰箱3种低温贮藏方式下生鲜牛奶品质变化

Changes in raw milk quality under three cooling conditions using domestic refrigerators

为明确家用冰箱3种低温贮藏下生鲜牛奶的品质变化规律,以提高生鲜牛奶的贮藏期.试验采集新鲜的牛奶样品,研究了0、4、10℃贮藏1、2、3、4、5 d期间生鲜牛奶品质变化.0℃贮藏的生鲜牛奶中有少量气泡产生,4℃和10℃贮藏的生鲜牛奶中有气泡产生和絮状物漂浮,伴有腐臭味;随着贮藏温度升高生鲜牛奶的L^*值减小加快;0℃贮藏对生鲜牛奶的酸度没有显著影响(P>0.05),4℃和10℃贮藏第5天生鲜牛奶的酸度显著升高(P<0.05);0和4℃贮藏,生鲜牛奶的乳蛋白和乳糖变化不显著(P>0.05);0、4、10℃贮藏,乳脂损失率分别为25.67%、31.11%、42.16%.相比4℃和10℃,家用冰箱0℃贮藏的生鲜牛奶品质良好,可为居民使用新型家用电冰箱贮藏牛奶提供借鉴.

This study aimed to investigate changes in raw milk quality under three different storage conditions using household refrigerators by measuring the fresh milk stored at 0,4,and 10 ℃ on day 1,2,3,4 and 5. The raw milk had small amount of bubbles when it was stored at 0 ℃. For raw milk stored at 4 or 10 ℃,bubbles,floating flocs and rancid smell were observed. The L^* value of the milk decreased rapidly with increasing storage temperature. Moreover,0℃ storage had no significant influence on the acidity of raw milk ( P >0.05),while it increased significantly on the 5 th day ( P <0.05) at 4 and 10 ℃. In addition,the contents of protein and lactose in raw milk had no significant changes when stored at 0 or 4 ℃( P >0.05). Moreover,the loss rates of fat content of raw milk were 25.67%,31.11%,and 42.16% at 0,4 and 10 ℃,respectively. Therefore,0 ℃ can better retain raw milk quality for household refrigerators. The results of current study provide useful reference for residents to use household refrigerators to store milk.