The yellow-orange chromogenic bacteria, commonplace in cannery environments, are capablo of producing spoilage in a variety of presterilized milk-based canned products. A wide range of cultures of these arbitrarily defined flavobacteria, including the particular food spoilage types, were subjected to taxonomic studies. A possible scheme permitting the grouping of spoilage from nonspoilage types is presented.

I t is recognized that, arising from their clump-forming characteristics, the flavobacteria are resistant to the disinfectants commonly used in canneries; these organisms are, therefore, frequently found as contaminants in cooling water and on wet post-process can handling equipment. Hitherto, there has been no suggestion of flavobacteria being involved in the spoilage of canned foods, and laboratory studies confirmed their inability to develop in canned vegetables.I t has now been demonstrated that there is a spoilage hazard from the flavobacteria for at least some varieties of milk-based canned products. A somewhat prolonged delay occurs between infection and the manifestation of spoilage, and contaminated packs do not become blown.

Thin‐layer chromatography was investigated as an inexpensive alternative to traditional microbiological techniques for the detection of microbial growth in canned vegetables. It was compared with culture methods, pH determination and direct microscopy in batches of canned vegetables with a known incidence of spoilage.

The heat resistance of Staphylococcus aureus NCTC 10652 in tris-maleate buffer pH 7.0 was increased by 4 or 8% w/v NaCl (P=O-OOl). At pH 6.5 the D,,,.c in both buffer and meat macerate was increased by 8% w/v NaCl. Addition of NaNO, had little effect on the heat resistance.

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