Occurrence and levels of Bacillus cereus in powder milk marketed in the city of São Paulo (SP), Brazil -1987/1988

Abstract

Although usually considered as a food with low contamination levels, powder milk can present bacterial spores such as Bacillus cereus, If the milk is reconstituted and maintained under inadequate temperatures, spores can germinate and the resulting bacterial contamination can cause to food borne infections. To isolate and quantify organisms of the Bacillus cereus species in whole milk powder, 72 samples of the product were collected in stores located in the city of São Paulo in 1987 and 1988. After being reconstituted, 32 of these samples were maintained under inadequate storage temperatures (200 C for 24 hours) to determine the B. cereus counts, Two of the 72 samples of the study had results above the standards established by the Brazilian Ministry of Health (1987). The samples stored under inadequate temperatures showed leveis 91.6% higher than the standards. From the viewpoint of B. cereus presence, the results obtained show that 97.22% of the samples of this study were adequate for consumption. However, 91.67% of the samples could potentially result in food borne infections due to the high B. cereus levels detected after the storage conditions used in this study.