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Title: THE EFFICACY OF SANITIZERS ON THE REDUCTION OF E. COLI O157:H7 FROM SHREDDED CARROTS UNDER SIMULATED PROCESSING CONDITIONS

Author
item GONZALEZ, ROLANDO - UMN
item Luo, Yaguang - Sunny
item RUIZ-CRUZ, SAUL - MEXICO
item McEvoy, James

Submitted to: International Fresh Cut Produce Association
Publication Type: Abstract Only
Publication Acceptance Date: 2/6/2004
Publication Date: 4/18/2004
Citation: Gonzalez, R.J., Luo, Y., Ruiz-Cruz, S., McEvoy, J.L. 2004. The efficacy of sanitizers on the reduction of E. coli O157:H7 from shredded carrots under simulated processing conditions. International Fresh Cut Produce Association Annual Meeting. p. 13.

Interpretive Summary:

Technical Abstract: Fresh-cut produce is one of the hottest growing convenience foods in history. Unfortunately, contamination with pathogenic microorganisms can occur anywhere in their journey from farm to table. Given that these products are marketed as read-to-eat, and therefore not subjected to further microbial killing steps, the need for effective disinfecting agents is clearly evident. In a common scenario of water recycling in the produce industry, chlorine, which has been traditionally used to sanitize produce, is readily inactivated upon contact with organic matter. Some manufacturers claim that newly developed products are not affected by high levels of organic matter content in the wash water, and this study was aimed to provide a side-by-side comparison of the efficacy of chlorine and three other commercially available sanitizers in reducing the numbers of E. coli O157:H7, total aerobic bacteria and yeasts and molds from artificially-inoculated shredded carrots under simulated commercial processing conditions of water reutilization. Fresh carrots shreds were inoculated with E. coli O157:H7 (Nalr) to an initial inoculum level of 106 CFU/g, and washed in sanitizer solutions of 200 ppm chlorine, 1% Pro-San, Tsunami 100 (80 ppm peroxyacetic acid), or 1000 ppm SANOVA (acidified sodium chlorite) prepared in fresh tap water or simulated processing water with a chemical oxygen demand level of approximately 3,500 mg/L. Samples were packaged and stored at 5°C for 14 d, with microbial sampling performed at days 0, 7 and 14. We found that SANOVA® provided a strong pathogen killing effect in both tap water and process water conditions with more than a 3.5 log reduction when compared to a tap water wash, and no survivors seen even after a 24-h enrichment step. E. coli O157:H7 was not recovered on SANOVA® treated samples during the entire 14 days storage period. The role of sanitizers in maintaining the microbial safety of wash water was also evaluated, with no recovery of E. coli O157:H7 or total bacteria from sanitizer solutions used to disinfect, eliminating the possibility of cross-contamination of other produce and potential quality deterioration. These results suggest that SANOVA® holds considerable promise as an alternative sanitizer of fresh-cut produce.