Abstract: Lactic acid bacteria play a dual role by enhancing both the flavor and nutritional benefits of fermented foods, and helping the body to prevent a variety of diseases caused by oxidation. The fulfillment of these beneficial functions is inseparable from the antioxidant activity of lactic acid bacteria. This article elaborates on the antioxidant mechanism of lactic acid bacteria including regulating antioxidant enzymes, regulating signaling pathways, scavenging free radicals, and inhibiting lipid peroxidation and metal ion chelation. The current status of the application of the antioxidant activity of lactic acid bacteria in dairy, meat, aquatic, and fruit and vegetable products is also reviewed. Finally, this article outlines the in vitro and in vivo evaluation methods for the antioxidant activity of lactic acid bacteria, aiming to provide a reference for deepening the application of lactic acid bacteria in the food processing sector.

Key words: lactic acid bacteria; antioxidant activity; mechanism of action; food processing; assessment methods