The probiotic properties of Enterococcus faecium strains isolated from buffalo milk : food matrix studies

Abstract

Buffalo milk has been increasingly explored in the production of dairy foods. Given the diversity of lactic acid bacteria present in this raw material, the functional potential of this type of milk should be studied. This study aims to assess the probiotic potential of two strains of Enterococcus faecium isolated from buffalo milk. We evaluated E. faecium M7AN7-1 and E. faecium M7AN10 for sustained cell viability under different conditions of conservation. We also assessed adhesion and cell viability in a simulated gastrointestinal transit test. E. faecium M7AN10 was selected for microencapsulation in sodium alginate and testing in the food matrix. The isolates maintained cell viability after refrigeration, freezing, and freeze-drying. E. faecium M7AN10 showed higher concentrations of viable cells than E. faecium M7AN7-1 after 180 min of contact with simulated gastric fluid, reaching 7.19 ± 0.59 Log10 CFU mL-1. We also observed sustained cell viability after exposure to simulated intestinal fluid. After encapsulation, E. faecium M7AN10 was tested in the food matrix of UHT milk. Cell count viability was maintained and its release was sustained in this medium for 30 days. The results of the in vitro assessment demonstrated that E. faecium M7AN10 remained functionally active under these experimental conditions. Similarly, they showed that it is a bacterium capable of sustaining viability in this type of food and after transit in a simulated gastrointestinal tract. Based on the data, we suggest this isolate may be a probiotic bacterial candidate for in vivo behavioral assessment.