奶粉中单增李斯特氏菌热抵制特性的研究

THE CHARACTERISTIC OF HEAT RESISTANCE FOR Listeria monocytogenes IN POWDERED MILK

[目的]对奶粉中单增李斯特氏菌的热抵制特性进行研究。[方法]通过人工方法将单增李斯特氏菌按107cfu/mL的浓度分别添加于提前预热的60℃的灭菌蒸馏水、复水的原料粉和复水的高糖高脂奶粉中,在此温度下分别作用5min和10min,通过菌落计数分析单增李斯特氏菌的热抵制特性。[结果]在灭菌蒸馏水中单增李斯特氏菌衰减得最快,在复水的原料奶粉中单增李斯特氏菌衰减得较慢,而在复水的高糖高脂奶粉中单增李斯特氏菌衰减得最慢。[结论]奶粉中的单增李斯特氏菌具有热抵制特性,而且高糖高脂成分可提高单增李斯特氏菌的热抵制能力。

To study the characteristic of heat resistance for Listeria monocytogenes in powdered milk. Listeria monocytogenes was added into sterile distilled water, reconstituted raw powdered milk and reconstituted powdered milk with high sugar and fat at a density of 107cfu/mL respectively and kept them at 60℃ for five minutes and ten minutes respectively, the characteristic of heat resistance for Listeria monocytogenes in powderedmilk was analyzed by counting. The number of Listeria monocytogenes in sterile distilled water decreased very quickly, the number of Listeria monocytogenes in reconstituted raw powdered milk decreased more slowly and the number of Listeria monocytogenes in reconstituted powdered milk with high sugar and fat decreased the most slowly. Listeria monocytogenes in powdered milk has the characteristic of heat resistance, high sugar and fat can help to increase heat resistance of Listeria monocytogenes.