高压脉冲电场处理草莓汁中损伤亚致死大肠杆菌与酿酒酵母的检测

Occurrence of sublethal injury of Escherichia coli and Saccharomyces cerevisiae after pulsed electric fields in strawberry juice

摘要: 为探寻高压脉冲电场对果汁中微生物的杀灭情况,揭示亚损伤微生物的存在及其影响因素。以草莓汁为原料,研究了不同处理条件下,高压脉冲电场对草莓汁中大肠杆菌和酿酒酵母损伤亚致死细胞产生的影响。结果表明,草莓汁中大肠杆菌亚致死细胞数目受高压脉冲电场处理条件的影响较为显著,在一定处理条件下(25kV/cm、200μs、10℃)大肠杆菌亚致死对数值最高达到1.339,亚致死细胞数目较多;但酿酒酵母亚致死情况受处理条件的影响较小,且亚致死对数均低于0.4,亚致死细胞产生数目较大肠杆菌少。

Abstract: The objective of this study was to evaluate the existence and its influential effects of sublethal microorganisms treated by pulsed electric fields ( PEF ) in fruit juice . Effects of PEF on the occurrence of sublethal injury of Escherichia coli and Saccharomyces cerevisiae in different conditions in strawberry juice were investigated. Results showed that the influences of PEF on the number of E.coli sublethally injured cells were more significant . Under certain conditions ( 25kV / cm , 200μs , 10 ℃ ) , the sublethal logarithm of E . coli reached 1.339. On the contrary, the influence of PEF on the number of S.cerevisiae sublethally injured cells was smaller. And its sublethal logarithms were all below 0.4, which meant less sublethal cells.