Optimization of fermentation parameters by response surface methodology and the antioxidant capacity of Myrica rubra wine

Objective: To optimize the fermentation parameters of Myrica rubra wine.Methods: Ethanol concentration as response value, the experimental factors including sugar concentration, inoculums size, fermentation temperature, p H and fermentation time were investigated to optimize the fermentation parameters of Myrica rubra wine, and the mathematical mode was established by response surface method ( RSM) . Meanwhile, the antioxidant activity of Myrica rubra wine was assessed by scavenging assays of hydroxyl radicals, ABTS+·, DPPH·, and superoxide anion free radicals.Results: The optimum conditions obtained by RSM were as follows: the inoculums size 0.03%, sugar concentration 22%, fermentation temperature 28 ℃, p H3.5, fermentation time 7 days. Under the optimal conditions, the predicted ethanol concentration by mathematical model was11.03%, while the experimental concentration was 10.87%, with a difference of less than 2%. At the same time, the results showed that Myrica rubra wine had good antioxidant activity, ABTS· 55.47%, hydroxyl radicals 57.24%, superoxide radical48.15%, DPPH·88.65%.Conclusion: The optimum fermentation conditions of Myrica rubra wine by RSM was convenient and feasible.