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, <em>Clostridium</em> spp<em>.</em> had the highest spoilage potential and had a major effect on the spoilage rate of VP lamb (based on sensory assessment). <em>C. estertheticum</em> caused premature ‘blown pack’ spoilage; however, the spoilage was delayed in a community setting. <em>C. putrefaciens</em> and <em>C. algidicarnis</em> caused premature spoilage of VP lamb independently and in a community setting. In contrast, all facultative anaerobes and <em>Pseudomonas</em> sp. tested were not capable of spoiling meat independently or within a community, expect for <em>Carnobacterium divergens</em> and <em>Serratia</em> spp., which spoiled meat prematurely when present in a community. Overall, these results highlight that <em>Clostridium</em> 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 <em>Clostridium</em>.