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

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