Toxin occurrence time in relation to sensorial changes in meat cans contaminated with Clostridium botulinum type B...

The study concerning dissemination and expansion of spore-forming rods and the possibility of botulinum toxin occurrence was performed on meat cans model contaminated experimentally with Clostridium botulinum type B366 toxigenic strain endospores. Meat cans were contaminated with the spore suspension of 4 x 10(3) spores per can and they were stored at 30 degrees C. Methodically visible toxigenicity (biological assay performed on white mice) took place in 84.3% cases by the time deformation of contaminated cans took place. When the first can bulging occurred almost 50% of contaminated cans were sensorially estimated as useful for consumption but almost 40% of them already contained toxin. In comparison to contaminated cans estimated sensorially as useful for consumption (in each experimental group) the percentage was established where the presence of toxin was determined as "consumer's risk". The mean value of those percentages was 76.4% for all experimental groups. In the studies on the vegetation dynamics and C. botulinum rods and toxin expansion in contaminated cans, we demonstrated the spore-forming rods dissemination, as well as limited range of toxin occurrence. Undertaken studies demonstrate that the process of toxigenicity often precede of accumulation of metabolic gases responsible for cans' deformation, as well as generation of visible sensorial changes which disqualified the contaminated cans for consumption.