A pilot plant scale evaluation of a new process aid for enhancing chlorine efficacy against pathogen survival and cross-contamination during produce wash

• Published in: International journal of food microbiology 2012-08, Vol.158 (2), p.133-139
• Main Authors: Luo, Yaguang, Nou, Xiangwu, Millner, Patricia, Zhou, Bin, Shen, Cangliang, Yang, Yang, Wu, Yunpeng, Wang, Qin, Feng, Hao, Shelton, Dan
• Format: Article
• Language: English
• Subjects: Chlorides; chlorine; Chlorine Compounds; Chlorine Compounds - pharmacology; Colony Count, Microbial; cross contamination; Disinfectants; Disinfectants - pharmacology; drug effects; E. coli O157:H7; Escherichia coli; Escherichia coli O157; Escherichia coli O157 - drug effects; Escherichia coli O157 - growth & development; Food Contamination; Food Contamination - prevention & control; Food Handling; Food Handling - methods; food processing; Food Safety; fresh produce; Fresh-cut produce wash; growth & development; industry; infants; Lactuca sativa var. capitata; leaves; Lettuce; margin of safety; methods; microbiology; Organic load; pathogen survival; pathogens; pharmacology; Plant Leaves; Plants; prevention & control; process control; risk; spinach; Spinacia oleracea; Spinacia oleracea - microbiology; washing; Water; water quality
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2012.07.008

Developing food safety intervention technology that can be readily adopted by the industry often requires test conditions that match as closely as possible to those of commercial food processing operations; yet biosafety risks inherent in pathogen studies constrain most experiments to laboratory settings. In this study, we report the first semi-commercial pilot-scale evaluation of a new process aid, T128, for its impact on enhancing the antimicrobial efficacy of chlorinated wash water against pathogen survival and cross-contamination. A non-pathogenic, BSL-1, strain of Escherichia coli O157:H7 was inoculated onto freshly harvested baby spinach leaves and washed with large amounts of freshly cut un-inoculated iceberg lettuce shreds in wash water with free chlorine periodically replenished, in the presence or absence of T128. Changes in water quality and pathogen survival and cross-contamination were monitored at every 2min intervals for up to 36min for each treatment during the wash operation. Results indicated that the use of T128 did not significantly (P>0.05) influence the rate of wash water deterioration, nor the pathogen populations remaining on the inoculated spinach leaves. However, in the absence of T128 (control), survival of E. coli O157:H7 in wash water and cross-contamination of un-inoculated lettuce frequently occurred when free chlorine in solution dropped below 1mg/l during the wash process. In contrast, the use of T128 significantly reduced the occurrence of E. coli O157:H7 surviving in wash water and of cross-contamination to un-inoculated shredded iceberg lettuce under the same operational conditions, suggesting that the application of T128 in a chlorine-based fresh produce sanitization system could increase the safety margin of process control on fresh-cut operations. ► Sanitizer concentration decreases rapidly during commercial fresh-cut produce wash. ► Pathogen survival and spread occur when sanitizer concentration nears depletion. ► This pilot plant study evaluated the performance of a novel process aid.