Date Full Report Received05/28/2010
Date Abstract Report Received05/28/2010
Funded ByNational Pork Board
Previous research on pork variety meats reported a 2% lactic acid spray was the most effective antimicrobial of those tested with the least negative effect on product quality (Zerby et al., 1998). However, as there has been limited if any implementation of these interventions, the purpose of the proposed research was to validate the effect of current industry practices of chilling and freezing pork variety meats, with and without the application of lactic acid, on the survival of pathogens of concern to the pork industry. Four different variety meats (liver, heart, intestines and stomach) were inoculated with three different pathogens (Salmonella, Campylobacter and Yersinia) and subjected to four different chilling treatments (with and without the application of 2% lactic acid). Samples were taken before treatment, after treatment and throughout a six-month shelf-life to measure the level of reduction or survival of each organism. Additional testing was performed on uninoculated samples to evaluate the reduction and survival of aerobic plate count, total coliforms and Escherichia coli before and after treatment and throughout shelf-life. Although an extensive baseline was developed and intervention strategies were evaluated for pork variety meats in 1998, the majority of the pork industry continues to depend on conventional refrigeration and freezing as their primary methods for controlling microbial growth in these products.
With the reported increase in export of pork products, U.S. pork and pork variety meats are now more than ever before subject to the scrutiny and expectations of the countries we trade with. Some countries are more accepting of antimicrobial interventions such as organic acids than other countries. While other countries may approve of the application of water-based antimicrobial treatments, such as hot water, they may not approve of water-based antimicrobials containing additional levels of chlorine that might serve as an effective antimicrobial. In addition, due to the low relative monetary value of variety meats as compared to carcass meats, most decontamination interventions during the slaughter process are directed at carcass meats. Therefore, a company may be totally dependent on refrigeration and/or freezing for microbial control. Utilizing validated and published procedures, whether they are antimicrobial treatments of a chemical nature or commercial refrigeration and freezing, will greatly support processors of pork variety meats whether they do business on a domestic or an international level. Overall, the use of 2% lactic acid as a decontamination intervention in addition to good GMPs (employee hygiene, sanitation, and rapid chilling) during processing of pork variety meats results in significant reductions in levels of Salmonella, Y. enterocolitica, and C. coli, as well as indicator organisms (APC, ECC, and TCC). However, significant reductions were also observed on variety meats treated with only a water wash and subsequently frozen. Trends in levels of APC, ECC, and TCC are similar to trends in levels of pathogens and can thus be used as surrogates for pathogens to monitor and validate processes in plants. Results did vary between the different types of variety meats suggesting that one intervention may not be suitable for all products. The results of this study may be used to support industry best practices for reducing pathogens in pork variety meats destined for export.