Spoilage potential of bacterial species from chilled vacuum-packed lamb

The objective of this study was to establish whether specific organisms play important roles in the spoilage rate of vacuum-packed (VP) lamb at low storage temperatures. The spoilage potential of representative organisms (n = 13) of the spoilage community of VP lamb were investigated through a series of shelf-life challenge trials. Each isolate was individually inoculated onto sterile (irradiated) and non-sterile (i.e., containing natural microbial community) VP lamb meat. Meat quality was assessed over time by measuring sensorial qualities, bacterial growth and pH. Among all test organisms, Clostridium spp. had the highest spoilage potential and had a major effect on the spoilage rate of VP lamb (based on sensory assessment). C. estertheticum caused premature ‘blown pack’ spoilage; however, the spoilage was delayed in a community setting. C. putrefaciens and C. algidicarnis caused premature spoilage of VP lamb independently and in a community setting. In contrast, all facultative anaerobes and Pseudomonas sp. tested were not capable of spoiling meat independently or within a community, expect for Carnobacterium divergens and Serratia spp., which spoiled meat prematurely when present in a community. Overall, these results highlight that Clostridium could be one of the main taxa driving the faster rate of quality loss of chilled VP lamb compared to beef. This research can help to inform opportunities for shelf-life extension by targeting organisms with ‘high’ spoilage potential, such as Clostridium.