高压脉冲电场对牛奶的杀菌研究

Study on Sterilization of Milk by High Intensity Pulsed Electric Fields(PEF)

牛乳营养丰富,利用高压脉冲电场技术结合巴氏杀菌对牛乳进行处理,可以很好地解决热处理不能解决的问题。可以在较低温度下,将乳中的微生物完全杀死。实验发现在牛奶的杀菌中,高压脉冲电场起主要作用,温度起辅助作用。随着电场强度的增加,灭菌效果增强,当电场强度达到75kv/cm时,可以将牛乳中的微生物完全杀灭。本文确定了能达到灭菌要求的最小的电场强度、最少的脉冲数及最低的处理温度;测定了在上述处理条件下乳营养的损失量,采用高压脉冲电场结合巴氏杀菌处理后的牛乳,其中的营养损失主要来自热处理,且这种方法比典型的巴氏处理具有更好的杀菌效果及更小的营养损失。

Milk contains enrich nutrition, When it is processed by the method that combined PEF technology with pasteurization, all problems that the conventional heat processing can＇ t solve can be solved properly, that is the microbes in milk can be completely inactivated in the lower temperature. The result shows that in the aspect of sterilization, PEF plays an important role, while the temperature gives auxiliary function. As soon as the PEF intensity increases, the inactivation effect increases too. The minimum PEF intensity, pulse number and processed temperature have been found in this research, and the losses of milk nutrition in different treatment condition have been measured, when processed by the method that combined PEF with pasteurization, the losses of milk nutrition are because of heat, and this method has better inactivation effect and less nutrition losses than the typical pasteurization.