Baseline Study on Microbial Contamination and Foodborne Pathogens in Industrially Processed Retail Meat: Towards Microbiological Criteria Settings

Abstract

For meat products at retail, no specific microbiological food safety criteria have been established, and comprehensive data on the bacterial contamination and presence of pathogens are mainly lacking. The present study addresses this gap by quantifying and analyzing the microbial load on different meat types from the two leading retail supply chains, supermarkets and butcheries in Belgium. A total of 286 meat samples, including beef fillets, minced beef, pork fillets, minced pork, chicken fillets, minced chicken, and chicken carcasses, were collected. Using ISO standards, the number of total aerobic bacteria (TAB), presumptive Pseudomonas, and Escherichia coli were determined, along with the presence of Salmonella spp. and Campylobacter spp. In general, chicken carcasses had the highest TAB counts, 7.38 ± 1.09 log10 CFU/g (Median ± IQR), and also the highest presumptive Pseudomonas counts 7.55 ± 1.11 log10 CFU/g (Median ± IQR). E. coli was predominantly present on chicken products while most beef and pork samples were below 10 CFU/g. Salmonella was isolated from 4.9% of the samples but solely from supermarket chicken products. Campylobacter was only present on chicken products, 14.8% from butcheries and 20.8% from supermarkets. Different microbial contamination levels were significantly higher on products from butcheries than on products from supermarkets. The expiration dates were only available for supermarket products and regression analysis revealed no significant increase in bacterial growth when products neared their expiration dates except TAB counts of minced beef, allowing sampling time points and criteria-setting independent of the storage time as long as it precedes the expiry date.  The log median values of the total aerobic bacteria and presumptive Pseudomonas of seven types of beef, pork, and chicken meat can be set as a reasonably achievable hygiene target. The contamination levels of E. coli on chicken products, urge for targeted interventions before retail, with stringent processing protocols, or the implementation of physical or chemical decontamination. The large distribution of microbiological contamination levels within the same meat type indicates the necessity of establishing food safety criteria to enhance consumer safety, though adapted to the selling point and packaging conditions.

Keywords: Microbial contamination, Foodborne pathogens, Meat safety, Escherichia coli counts, Pseudomonas counts, Campylobacter spp., Salmonella spp.