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Title: Chlorine wash for fresh-cut processing: Can it work better?

item Nou, Xiangwu
item Luo, Yaguang - Sunny
item Millner, Patricia
item Shelton, Daniel

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/16/2011
Publication Date: 5/16/2011
Citation: Nou, X., Luo, Y., Millner, P.D., Shelton, D.R. 2011. Chlorine wash for fresh-cut processing: Can it work better?. Meeting Abstract.

Interpretive Summary:

Technical Abstract: Chlorine is the most commonly used sanitizer for fresh-cut produce wash. Alternative sanitizers, such as ozonated water, peroxyacetic acid, electrolyzed water, have been developed and applied for fresh-cut produce sanitization, with varying degrees of success. Other technologies, such as electric beam irradiation, cold plasma, and ultrasound treatment, while promising, have not been commercially applied, due to various issues. Despite of the great technical advances in developing post harvest intervention strategies in the past decade, chlorinated water remains the most dominant sanitizing solution used in commercial fresh-cut produce processing. Currently, most commercially used sanitizers have limited efficacy against bacterial cells attached to the surfaces of leaves, therefore, the main benefits of sanitizer application is to safeguard water quality and prevent cross contamination during processing. One major challenge for chlorine wash of fresh-cut produce is the instability of free chlorine in the presence of high organic loads. Exudates from wounded tissue contain high organic load that readily inactivates free chlorine in wash solutions. If not replenished properly, free chlorine depletion in wash solution could create windows for bacterial cross contamination to occur. We evaluated the effect of whole leaf washing on cross contamination by E. coli O157:H7. Lettuce leaves were either shredded and washed in chlorinated water, as is the general practice in commercial processing, or washed as whole leaves followed by shredding. The whole leaf washing strategy can significantly reduce the potentials of bacterial cross contamination. Recently we have examined the effect of applying a diol-acid based wash aid to chlorinated wash solutions. The application of this wash aid significantly reduced the survival of bacterial pathogens in wash solution when free chlorine level reaches near depletion, therefore, increasing the safety margin of the process control.