|Kalchayanand, Norasak - Nor|
|KOOHMARAIE, MOHAMMAD - INSTITUTE OF ENVIRONMENTAL HEALTH LABORATORIES AND CONSULTING GROUP|
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2016
Publication Date: 4/14/2016
Publication URL: http://handle.nal.usda.gov/10113/62351
Citation: Kalchayanand, N., Koohmaraie, M., Wheeler, T.L. 2016. Effect of exposure time and organic matter on efficacy of antimicrobial compounds against Shiga Toxin-producing Escherichia coli and Salmonella. Journal of Food Protection. 79(4):561-568. doi: 10.4315/0362-028X.JFP-15-204
Interpretive Summary: E. coli O157:H7, non-O157 pathogenic E. coli, and Salmonella threaten consumers’ health as well as cause economic loss due to illnesses, product condemnation, and lower product demand. Although several antimicrobial compounds are effective in inactivating these pathogens, the effects of exposure time and the impact of the high organic load that antimicrobials encounter on the carcass surface would be useful to the fresh beef processing industry. The study evaluated the effectiveness of time of exposure of various antimicrobial compounds approved by the USDA Food Safety Inspection Service against seven serotypes of pathogenic E. coli strains and Salmonella in antimicrobial solutions with and without organic matter. The results of this study indicated that organic matter and exposure time influenced the efficacy of antimicrobial compounds against pathogens and should be considered when choosing an antimicrobial compound for an intervention.
Technical Abstract: Several antimicrobial compounds are in commercial meat processing plants for the purpose of pathogens control on beef carcasses. However, the efficacy of the method used is influenced by a number of factors such as spray pressure, temperature, type of chemical and concentration, exposure time, method of application, equipment design, and the stage in the process that the method is applied. The objective of this study was to evaluate effectiveness of time of exposure of various antimicrobial compounds against seven serotypes of STEC strains and Salmonella in aqueous antimicrobial solutions with and without organic matter. Non-O157 STEC, STEC O157:H7, and Salmonella were exposed to the following aqueous antimicrobial solutions with or without beef purge for 15, 30, 60, 120, 300, 600, and 1,800 s: (i) 2.5% lactic acid (LA2), (ii) 4.0% lactic acid (LA4), (iii) 2.5% Beefxide (BX), (iv) 1% Aftec 3000 (AF), (v) 200 ppm peracetic acid (PAA), (vi) 300 ppm hypobromous acid (BR), and (vii) water as a control. In general, increasing exposure time to antimicrobial compounds significantly (P = 0.05) increased the effectiveness against pathogens tested. In aqueous antimicrobial solutions without organic matter, both PAA and BR were the most effective in inactivating populations of STEC and Salmonella, providing at least 5.0 log reductions with exposure for 15 s. However, in antimicrobials containing organic matter, LA4 was the most effective compound in reducing levels of STEC and Salmonella, providing 2 to 3 log reductions with exposure for 15 s. The results of this study indicated that organic matter and exposure time influenced the efficacy of antimicrobial compounds against pathogens, especially with oxidizer compounds. These factors should be considered when choosing an antimicrobial compound for an intervention.