Psychrotrophic Clostridium spp. associated with ‘blown pack’ spoilage of chilled vacuum-packed red meats and dog rolls in gas-impermeable plastic casings

‘Blown pack’ spoilage of vacuum-packed chilled beef, lamb and venison, and of a cooked meat product, chilled dog rolls packed in an oxygen-impermeable plastic casing, was characterised by sensory, chemical and microbiological analysis. Investigation of the probable causative agents led to the isolation of eight strains of psychrotrophic clostridia. Three strains have been provisionally identified as C. difficile, C. beijerinckii and C. lituseburense; the other five remain unidentified. In inoculation studies only one isolate produced significant amount of gas on meat, causing pack ‘blowing’. It is, therefore, possible that ‘blown pack’ spoilage involves a synergism with one or more other organisms.