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342 PROCEEDINGS OF INTERNATIONAL SCIENTIFIC CONFERENCE ON APPLIED BIOTECHNOLOGYfound in conjugated forms and are difficult to absorb. Therefore, it is necessary to find effective methods that convert antioxidant compounds into free form to increase the value of rice bran. Fermentation is a traditional method to increase the functional components of plant materials. After fermentation, complex and difficult-to-digest components are transformed into simpler, more easily digestible forms. This process enhances the overall quality, color, taste, and bioactive components of the raw materials, such as phenolics, vitamins, minerals, and amino acids. It was reported to improve the biotransformation of phenolic compounds from their bound or conjugated forms to free form, therefore, phenolic and flavonoid content and antioxidant power are enhanced in cereal fermented by lactic acid bacteria [4]. In the fermentation process, bacterial glycosidase is an important enzyme that catalyzes the hydrolysis of glycosidic bonds in complex sugars, increasing bioactive compounds, nutrients, and the taste of fermented material. A previous study reported that flavonoids, aromatic, and ginkgolides in ginkgo tea were enhanced by glycosidase activity [5]. In this study, fermented probiotic strains were selected by glycosidase test, and three different lactic acid bacteria strains with high glycosidase activity isolated from fermented food were used in rice bran fermentation. After the fermentation process, the phenolic acid and flavonoid acid content was determined. Further, the antioxidant activities of rice bran extracts were evaluated via 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays.2. MATERIALS AND METHODS 2.1. Bacterial glycosidase activity