Development of the antioxidant activity in cheese whey and milk permeate using Lactobacillus acidophilus LA5 and Bifidobacterium animalis subsp. lactis BB12

Free radicals are a major cause of many diseases, such as cancer, by damage to the cells. The use of probiotic strains in fermented dairy foods has expanded due to the health-promoting effects of the consumer. Regarding antioxidant potentials of probiotic bacteria, the aims of this study compared the antioxidant activity of probiotic species L. acidophilus</em> LA5 and B. animalis</em> subsp. lactis BB12 used in foods and investigate effects of incubation temperature, Initial pH, fermentation time, yeast extract concentration and linoleic acid concentration on their antioxidant activity in enriched cheese whey and milk permeate. The results showed that fermentation time, incubation temperature and concentration of yeast extract were the most important factors that had a significant effect on both DPPH free radical inhibitory activity and hydroxyl radical scavenging activity (p <0.05). DPPH free radical inhibitory activity and hydroxyl radical scavenging activity increased with increasing incubation temperature and yeast extract concentration, respectively. Antioxidant activity was observed in the first 24 hours of the fermentation process, which was proportional to bacterial growth. Hydroxyl radical scavenging activity and DPPH free radical scavenging activity, as a result of the probiotic culture activity and their effect on the substrate, increased and decreased, respectively, in the first 24 hours of fermentation time, by the destruction the polymers. This study showed that the fermentation bioprocess by L. acidophilus</em> LA5 and B. animalis</em> subsp. lactis BB12 in the cheese whey as a medium had high antioxidant activity.