Purpose: To determine the current shelf-life and microbiological conditions of chilled VP pork and beef.
Methods: Beef and pork sub-primal cuts obtained from a federally inspected Canadian research abattoir were vacuum-packaged on the day of production and stored at 2 and -1.5°C. Organoleptic assessment and microbiological analysis were performed in triplicates at day 0 and at appropriate intervals for up to 190 days of storage. Selected bacterial isolates were identified to species level by 16S rRNA gene sequencing.
Results: The odours of beef stored at 2oC for ≤ 110 days or -1.5oC for ≤ 190 days were mostly acceptable. Acid or dairy odours for VP pork stored at 2oC for ≤ 60 days or at -1.5oC ≤ 120 days were detected upon opening, but dissipated after a 2 h display. Before storage, the numbers of total aerobes were approximately 2 and 3 log CFU/cm2 for pork and beef, respectively, with the beef microflora being mainly strict aerobes and pork microflora including a substantial fraction of species of Enterobacteriaceae. At the end of storage life, lactic acid bacteria were predominant in the microflora of beef at either temperature and pork at 2°C, while Rahnella aquatilis accounted for >50% of the final microflora on pork stored at -1.5°C .
Significance: The attainable storage life of Canadian VP pork and beef primal cuts is at least 120 and up to 190 days at -1.5°C. The microflora on beef and pork was different, indicating the animal sourced contamination.