Prevalence and behaviour of Bacillus cereus in a REPFED of Italian origin.
This paper reports on the prevalence and behaviour of Bacillus cereus in gnocchi, a REPFED of Italian origin. A survey of gnocchi under varying storage conditions, revealed that, although B. cereus was found in 33% of the samples, the contamination level was lower than 10(2) CFU/g for the unstored and the refrigerated (8 degrees C) samples. Counts increased with increasing storage temperatures and prolonged storage times in samples prepared without sorbic acid. The effect of different formulations (sorbic, citric and lactic acid) and storage conditions (8, 12 and 20 degrees C) have been evaluated in a challenge testing with spores of B. cereus. Results indicate that the 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 degrees C. On the contrary, when temperature abuse occurs (12 and 20 degrees C), lactic or citric acid are not able to prevent growth of B. cereus.
Department of Food Science, University of Udine, Italy. manueladeltorre@yahoo.it
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D001409:Bacillus cereus / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation; D005520:Food Preservatives / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007558:Italy; D015995:Prevalence; D013011:Sorbic Acid / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors
D005520:Food Preservatives; D013011:Sorbic Acid