Validation of Antimicrobial Interventions for Reducing Shiga Toxin–Producing Escherichia coli Surrogate Populations during Goat Slaughter and Carcass Chilling

Abstract

Demand and consumption of goat meat is increasing in the United States due to an increase in ethnic populations that prefer goat meat. As ruminant animals, goats are known reservoirs for Shiga toxin–producing Escherichia coli (STEC) and proper handling, especially during slaughter, is imperative to reduce the likelihood of carcass and meat contamination. However, the majority of antimicrobial intervention studies during the slaughter of ruminant species have focused on beef, highlighting the need for validation studies targeting small ruminants, such as goats, during slaughter and chilling procedures. The objective of this research was to evaluate 4.5% lactic acid (LA; pH 2.1), peroxyacetic acid (PAA; 400 ppm; pH 4.7), a hydrochloric and citric acid blend (Citrilow [CL]; pH 1.2), 5% levulinic acid plus 0.5% sodium dodecyl sulfate (LVA+SDS; pH 2.60), and a nontreated control (CON) for their efficacy in reducing STEC surrogates and their effect on carcass color from slaughter through 24-h chill. Fifteen goat carcasses across three replications were inoculated with a five-strain cocktail (ca. 5 log CFU/cm2 attachment), containing rifampin-resistant surrogate E. coli (BAA-1427, BAA-1428, BAA-1429, BAA-1430, and BAA-1431) and were randomly assigned to an antimicrobial treatment. Antimicrobials were applied prechill and 24 h postchill. Mean log reductions achieved after prechill treatment with LA, PAA, CL, and LVA+SDS were 2.00, 1.86, 2.26, and 1.90 log CFU/cm2, respectively. Antimicrobial treatment after the 24-h chilling, resulted in additional reductions of surrogate E. coli by 0.99, 1.03, 1.94, and 0.47 log CFU/cm2 for LA, PAA, CL, and LVA+SDS, respectively. Antimicrobial treatments did not impact goat carcass objective color (L* and a*), except for b*. The antimicrobials tested in this study were able to effectively reduce surrogate STEC populations during slaughter and subsequent chilling without compromising carcass color.

In-Plant Validation of Novel On-Site Ozone Generation Technology (Bio-Safe) Compared to Lactic Acid Beef Carcasses and Trim Using Natural Microbiota and Salmonella and E. coli O157:H7 Surrogate Enumeration

“…Foreshank and chuck trim were chosen as the “worst case scenario” for this section as, historically, these are the two types of trim that the commercial beef processing plant had more frequently found presumptive E. coli O157:H7 presence. These surrogates have been previously seen to mimic E. coli O157:H7 and Salmonella resistance to antimicrobial treatments when used as a cocktail in validation trials [ 13 , 14 , 15 , 16 , 22 ]. In some cases, reporting a slight increase in the magnitude of survival of the surrogate compared to Salmonella or E. coli O157:H7 for a relatively higher margin of safety.…”

A descriptive review of the use of organic acids and peracetic acid as a decontaminating strategy for meat

“…These authors found effective results for reducing APC, improvements in color, and no difference in sensory. Thomas et al (2019) used goats carcasses artificially contaminated, washed with water, and treated with organic acids at prechill and 24 h postchill. The solutions tested positive for reducing STEC E. coli surrogate and minor color changes.…”