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

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.