加碱对牛奶酸度影响的研究.

Research on the Effect of Alkali in Milk Acidity

将不同干物质含量的新鲜牛乳于常温下存放,经过自然发酵酸败→加碱调酸→再酸败→再加碱调酸的一系列过程,测定其不同阶段乳样煮沸前后的酸度。结果表明,煮沸前后乳样酸度发生了很大的变化,且这个变化完全超出正常乳煮沸前后的变化规律。为了保证原料乳的质量,在生鲜牛乳的收购过程中,一方面要测定生鲜牛乳的酸度,另一方面也要测定其煮沸后的酸度及煮沸前后的酸度差。

When stored at room temperature, fresh milk in different contents of dry matter will be naturally fermented and rancid. Acidity detection for raw milk samples and boiled milk samples, was carried out at different stages in the process of adding alkali for acidity regulating, re-ferment and adding alkali for acidity regulating again. Result showd that acidity had changed significantly after the sample was boiled, which was completely beyond the normal range. In order to ensure the quality of raw milk in the acquisition process, on the one hand, measuring the acidity of fresh milk was necessary. On the other hand, it was essential for the boiled milk and calculation acidity difference before and after boiling