SURVIVING OF COMMERCIAL PROBIOTIC STRAIN Lactobacillus rhamnosus GG IN SLOVAK COW LUMP CHEESE EXPERIMENTALLY INOCULATED WITH Listeria innocua

Abstract

Cow lump cheese represents a traditional Slovak cheese. It belongs to fresh types of cheeses. The aim of this study was to test surviving of commercial probiotic strain Lactobacillus rhamnosus GG in cow lump cheese experimentally infected with L. innocua; (listeriae are contaminants) and to check the suitability of GG strain as additive for this product. The counts of GG strain in cow lump cheeses were well balanced during whole experiment. It was found in the counts from 5.48 ± 0.15 to 7.77 ±1.50 log10 cfu/g. Its maximum in cheese was 7.77 ± 1.30 log10 cfu/g on day 7 with stability up to day 14. The identity of GG strain isolated from cheeses was confirmed by PCR. The counts of other lactic acid bacteria were also well balanced during the whole experiment in the experimental cheeses with stability up to day 14. Only in E1/GG cheese, the highest number of LAB was detected (10.60 ±1.26 log10 cfu/g). The count of L. innocua LMG 13568 was not influenced. The pH and lactic acid values were not negatively influenced. Visually, the GG cheese provided a good structure (consistency).It can be disputed that shelf-life of the product could be maintained by this way and/or the product itself with GG strain can be consumed as afunctional food or to serve as a probiotic strain carrier.