A Study of Microbial Quality of Vacuum Packaged, Sliced Bologna ¹

A study of 113 samples of vacuum packaged sliced bologna offered for sale in the retail marketplace revealed a wide range of total microbial loads. The pH was not closely related with age or microbial load, within the manufacturers' expected shelf-life of the product. Approximately 55% of old samples had pH >6.0, and pH was influenced by manufacturer. Confirmed coliform bacteria were detected in 5% of samples, but Escherichia coli was absent (<3/10g). In contrast, group D streptococci were present, sometimes in large numbers, depending on manufacturer. Potentially pathogenic bacteria, including Clostridium perfringens (>10/g), coagulase positive Staphylococcus aureus (>25/g) and Salmonella (in 25 g of sample) were generally not detected. Only one sample contained >25 S. aureus /g. No relationship was observed between total microbial load and indicator organisms or pathogenic bacteria.