Prevalence and behaviour of Bacillus cereus in a REPFED of Italian origin

This paper reports on the prevalence and behaviour of Bacillus cereus in gn occhi, a REPFED of Italian origin. A survey of gnocchi under varying storag e conditions, revealed that, although B. cereus was found in 33% of the sam ples, the contamination level was lower than 10(2) CFU/g for the unstored a nd the refrigerated (8 degreesC) samples. Counts increased with increasing storage temperatures and prolonged storage times in samples prepared withou t sorbic acid. The effect of different formulations (sorbic, citric and lac tic acid) and storage conditions (8, 12 and 20 degreesC) have been evaluate d in a challenge testing with spores of B. cereus. Results indicate that th e use of sorbic acid in association with citric or lactic acid to pH 5.0 is effective in inhibiting growth of B, cereus and the anticipated shelf life of the product is safe even if temperature abuse occurs. If sorbic acid is omitted, lactic acid can inhibit B. cereus growth during storage at 8 degr eesC. On the contrary, when temperature abuse occurs (12 and 20 degreesC), lactic or citric acid are not able to prevent growth of B. cereus. (C) 2001 Elsevier Science B.V. All rights reserved.