In Vitro Antioxidant Properties of Lactobacillus Gasseri Isolated from Fermented Milk: Isolation and Preparation of Strains and Intracellular Cell-Free Extracts, Chemical Testing (Hydrogen Peroxide, Superoxide, Hydroxyl Radical, DPPH, Ferrous Ion Chelatin. Indones. j. sci. technol. 2024, 9 (3), 611-622.