Optimization of Submerged Fermentation in Mycelia by Grifola frondosa and Its Antioxidant Activities

In this paper,the optimal conditions for the fermentation of Grifola frondosa were studied by response surface methodology with glucose,peptone,KH₂PO₄,fruit and vegetable jujce dosage as factors and mycelia biomass as the index,and the antioxidant activity of mycelia was measured. The results showed that the optimal formula was:glucose dosage 2.5%(w·v^-1),peptone dosage 0.5%(w·v^-1),KH₂PO₄ dosage 0.1%(w·v^-1),fruit and vegetable juice dosage 15%(v·v^-1). In this condition,the mycelial dry weight prediction value was 19.06 mg·ml^-1,and the actual measured value is(18.12±0.214) mg·mL^-1 within the error range. The results showed that the scavenging rate of DPPH radical was 69.78%±6.17% when the mass concentration was 1.5 mg·mL^-1,and the clearance rate of ABTS free radical was 82.11%±7.24%;Hydroxide radical scavenging rate reached 59.73%±3.15%. Thus,the mycelia of the submerged fermentation of Grifola frondosa could be used as a potential antioxidant.