Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2000
Publication Date: 3/1/2001
Citation: Castelo, M.M., Kang, D., Siragusa, G.R., Koohmaraie, M., Berry, E.D. 2001. Evaluation of combination treatment processes for the microbial decontamination of pork trim. Journal of Food Protection. 64:335-342. Interpretive Summary: Applying antimicrobial treatments to meat trim would provide an additional means to reduce any bacterial contamination prior to grinding, thus reducing the probability of pathogen presence in the final ground product. The objective of these experiments was to develop combination treatment processes for the microbial decontamination of pork trim. In the first experiment, the optimum exposure times and/or temperatures of high pressure water washes, hot water washes, ambient-temperature 2 percent lactic acid washes, and hot air treatments to reduce fecal bacteria from pork trim were determined. These results were used in the second experiment, where these individual treatments were combined into four different multiple-step processes and evaluated for their ability to reduce the numbers of bacteria on lean and fat pork trim. All of the combination processes were more effective than high pressure water washes alone at reducing the bacterial populations examined, which included coliform (fecal) bacteria and biotype 1 Escherichia coli. Combination processes that used hot water and hot air treatments had detrimental effects on the color and emulsion stability of the ground pork, while water washes alone or a combination of water and lactic acid washes reduced bacterial populations without affecting these quality attributes.
Technical Abstract: Combination treatment processes for the microbial decontamination of pork trim were developed. Lean pork trim (LPT) inoculated with swine feces was treated with interventions including water (W, 15 deg C, 65 lb/in**2), 2 percent lactic acid (LA, 15 deg C, 35 lb/in**2), hot water (HW, 35 lb/in**2) or hot air (HA) at different exposure times and/or temperatures, to determine the optimum parameters for reducing coliforms with individual interventions. Based on these results, three combination processes were developed. LPT and fat-covered pork trim (FPT) were inoculated with swine feces and treated as follows: Control; W (120 s); W followed by LA wash (75 s; W + LA); combination 1 (Comb 1; W + HW [65.5 deg C, 15 s] + HA [510 deg C, 60 s] + LA); Comb 2 (W + HW [82.2 deg C, 15 s] + HA [510 deg C, 75 s] + LA); and Comb 3 (W + HW [82.2 deg C, 45 s] + HA [510 deg C, 90 s] + LA). Populations of aerobic and psychrotrophic bacteria, coliforms, Escherichia coli, and lactic acid bacteria (LAB) were determined before and after treatments, and at days 2 and 7 of 4 deg C storage. LPT or FPT treated with W + LA, Comb 1, Comb 2, and Comb 3 had lower remaining microbial populations immediately after treatment than W-treated samples. Populations of aerobic bacteria, coliforms, E. coli and LAB on both LPT and FPT did not increase over the 7-day storage period. For all treatments, microbial populations were lower on FPT than on LPT after treatment and during storage. Treatment of pork trim with any of the combination treatments significantly (P<0.05) affected the color and emulsion stability of the ground pork, while W and W + LA were the most favorable treatments for reducing microbial populations without affecting these quality attributes.