Effects of Probiotic Lactobacillus Rhamnosus LOCK900 on the Staphylococcus Aureus Survival in Carrot Juice

Abstract

The objective of this study was to assess the effects of Lb. rhamnosus LOCK900 probiotic additive, lactic acid and incubation process, i.e., the moment of S. aureus contamination on the growth and survival rate of the pathogen in carrot juice. Both the Lb. rhamnosus LOCK900 additive and the incubation process (32C) had an impact on the number of S aureus in the carrot juice (P 0.05). Lactic acid, particularly in the product inoculated with the pathogen and incubated was not sufficient to hinder the development of S. aureus. The increase of S. aureus number in carrot juice with lactic acid indicates its acid resistance. The adaptation mechanism was observed also in sample inoculated with pathogen before fermentation. Gradually increasing acidity did not inhibit S. aureus proliferation. Inhibitory effect of Lb. rhamnosus LOCK900 was revealed during storage of P1 sample but the highest suppress was observed when pathogen's inoculation occurred after fermentation. Practical Applications In recent years, an increasing interest has developed in functional foods, including food with probiotics. The basic requirement that has to be fulfilled during the food production and turnover process is to ensure that food will not do any harm to the consumer (CAC/RCP 2008). The results obtained in this work help in understanding the situation of using contaminated raw materials or cross contamination that may happen during the production of probiotic food. In particular mechanisms of S. aureus survival during food fermentation. The outcome might be taken into account for the development and optimization of functional food preservation processes.