Incorporation of probiotic bacteria in whey cheese: decreasing the risk of microbial contamination.

The use of probiotic can extend the shelf life of whey cheeses and make them safer by delaying or preventing growth of contaminant bacteria

For dairy products that are consumed fresh, contamination by spoilage microorganisms and pathogens from the environment is a major concern.

Contamination has been associated with a number of outbreaks of foodborne illnesses; however, consistent data pertaining to the microbial safety of whey cheeses specifically have not been reported.

The goals of this research effort were to manufacture a probiotic whey cheese with Bifidobacterium animalis and Lactobacillus casei and to assess the antimicrobial activity of these probiotics against a set of foodborne pathogens (Listeria innocua, Salmonella enteritidis, and Staphylococcus aureus) and food spoilage microorganisms (Pseudomonas aeruginosa and Escherichia coli).

 Three ranges of these microbial contaminants were used for inoculation of cheeses. The inhibition produced by the probiotics was calculated, and the major effect was found to be bacteriostatic.

The results showed that in specific cases, full inhibition was observed by Bifidobacterium animalis against Pseudomonas aeruginosa and by Lactobacillus casei against Salmonella enteritidis and Listeria innocua.

Conversely, the least inhibition was detected for Lactobacillus casei against Pseudomonas aeruginosa.

These results suggest that use of these probiotic strains can extend the shelf life of whey cheeses and make them safer by delaying or preventing growth of common contaminant bacteria.

 Source: J Food Prot. 2011 Jul ; 74(7):1194-9

http://www.ncbi.nlm.nih.gov/pubmed/21740724

Aporte: Fernando Fuentes Pinochet