Increased Extracellular Saponin Production after the Addition of Rutin in Truffle Liquid Fermentation and Its Antioxidant Activities

Saponins possess a variety of pharmacological effects and exhibit great potential in the food industry as bioactive substances. In this study, extracellular saponin production via liquid fermentation Tuber melanosporum occurred with addition rutin. For purpose, medium composition culture conditions were optimized using single-factor experiments an orthogonal experiment design. The optimal consisted glucose (43.5 g/L), peptone (6 KH2PO4 (1.15 NaCl (0.2 vitamin B2 (0.082 B6 (0.1 C (0.02 rutin (4.8 g/L). follows: 12.5% (v/v) inoculation, volume 50 mL/250 mL flask, temperature 24 °C, shaker speed 190 rpm, initial pH 5.7, time 96 h. Finally, maximal content 0.413 g/L was obtained, which 134.7% higher than that base medium. Rutin proved to be excellent promoter, because increased by 50.2% compared without 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, hydroxyl radical ferric reducing antioxidant power truffle saponins reached 94.13%, 79.26%, 42.22 mM, respectively. This study provides useful strategy for fungal flavonoid compounds.