Causes of spoilage of thermally processed fish in Morocco

Of 946 cans of fish suspected of being spoiled, which were collected from local stores and canneries in Morocco, 484 cans (51%) had major container defects. Leaking seams at the manufacturer's end and droops and vees on the canner's end were the most prevalent defects (36 and 28%, respectively). Upon microbiological analysis of 256 cans, viable micro-organisms were recovered from 168 cans, of which 72% contained typical leaker spoilage organisms, while 28% contained typical underprocessing spoilage organisms. Thermophilic organisms were found in association with other organisms in half of the cans. The more severe the swell, the greater were the chances of recovering micro-organisms. The scoring system of Davidson & Pflug (1981) indicated that 16% and 71% of the cans had seams of questionable and poor quality, respectively, and these had a potential for leakage. The most probable cause for spoilage was determined: leakage, 80%; non-microbial swells, 10%; underprocessing, 10%.