Preparation and functional properties of probiotic and oat-based synbiotic yogurts fermented with lactic acid bacteria

The main purpose of the current study was to assess the physicochemical properties of the synbiotic yogurt fermented with oat slurry and probiotic strains and the antioxidative and antibacterial activities of the oat-based synbiotic yogurt. The viable cells of Lactobacillus brevis SBP49 and Lactobacillus acidophilus SBP55 reached 10 8 CFU/g or more in the probiotic and oat-based synbiotic yogurt, and the resistance to artificial digestive juices and the adherence to intestinal epithelial cells of these lactic acid bacteria were also very high in these yogurts. In addition, oat flour added for the manufacture of the synbiotic yogurt significantly promoted the production of antimicrobial substances by these probiotics, thereby increasing the antibacterial effect of the strains against pathogenic food poisoning bacteria including Bacillus cereus American Type Culture Collection (ATCC) 11778, Escherichia coli O157 ATCC 43889, Listeria monocytogenes Korean Collection for Type Cultures (KCTC) 3569, Salmonella enteritidis ATCC 13076, Salmonella typhimurium KCTC 2514, and Staphylococcus aureus ATCC 6538. Meanwhile, the antioxidative activity of the oat-based synbiotic yogurt was significantly higher than that of the probiotic yogurt and its activity may be due to free radical scavenging ability of phenolic compounds contained in oat slurry.