Rapid Field Screening Method for Flat Sour Spoilage

A rapid field test based on bacterial catalase was developed to detect flat sour spoilage of shelf stable canned meats. Containers of canned corned beef were spoiled by inoculating with spores of Bacillus stearothermophilus and/or B. coagulans and incubating at 55°C. Spore outgrowth was evident and vegetative cells were usually recovered at levels of at least one order of magnitude above the original spore load. Although neither abnormal odors nor significant pH shifts were detected, catalase was consistently demonstrated in all spoiled samples.