American Dairy Science Association Joint Annual Meeting, Arizona, United States Of America, 2 - 07 July 2012, vol.95, pp.650
An erythromycin resistant strain of probiotic Lactobacillus paracasei ssp. paracasei LBC-1 (LBC-1e) was added to part skim Mozzarella cheese in alginate microencapsulated or free form at a level of 108 and 107 cfu/g respectively. The objective of this study was to investigate the survival of LBC-1e and total lactic acid bacteria through the pasta filata process of cheese making where the cheese curd was heated to 55°C and stretched in 70°C-hot brine, followed by storage at 4°C for 6 wk and subjected to simulated gastric and intestinal digestion. This included incubation in 0.1 M and 0.01 M hydrochloric acid, 0.9 M phosphoric acid and a simulated intestinal juice consisting of pancreatin and bile salts in a pH 7.4 phosphate buffer. There were some reductions in both free and encapsulated LBC-1e during heating and stretching with encapsulated LBC-1e surviving slightly better. Changes in total lactic acid bacteria losses during heating and stretching did not reach statistical significance. During storage there was a decrease in total lactic acid bacteria but no statistically significant decrease in LBC-1e. Survival during gastric digestion in HCl was dependent on extent of neutralization of HCl by the cheese with more survival in the weaker acid in which pH increased to 4.4 after cheese addition. The alginate microcapsules did not provide any protection against the HCl. Interestingly, there was greater survival of the encapsulated LBC-1e during incubation in H3PO4. Proper selec- tion of simulated gastric digestion media is important for predicting delivery of probiotic bacteria into the human intestinal tract. Neither free nor encapsulated LBC-1e was affected by incubation in pancreatin/ bile solution. It was concluded that based on survival during simulated gastric digestion, the level of probiotic bacteria that would need to be added to cheese to provide a beneficial health benefit is lower than is generally assumed for other fermented dairy foods or when consumed as supplements.
Key Words: microencapsulation, probiotic, Mozzarella