Efficacy of alkaline washing for the decontamination of orange fruit surfaces inoculated with Escherichia coli

Abstract

The effectiveness of washing treatments to decontaminate orange fruit surfaces inoculated with Escherichia coli was evaluated. Washing on roller brushes with fruit cleaners or sanitizers followed by potable water rinse reduced E. coli by 1.9 to 3.5 log cycles. Prewetting fruit for 30 s before washing provided no significant benefit in most cases. Additional sanitizing treatments either with chlorine or acid sanitizers did not enhance the results of alkaline washing. In general, high pH washing solutions (pH 11.8) applied with an adequate spray volume effectively reduced the surface contamination of fruit that lowered the microbial load of fresh juice as well.