Optimization of Fermentation Technology of Malus doumeri (Bois) Chevalier and Zizyphus jujube Mill. Compound Fruit Wine by Response Surface Methodology and Its Antioxidant Activity Analysis

In order to develop a new brewing technology of compound fruit wine and analyze its antioxidant activity, the compound fruit wine was prepared from Malus doumeri (Bois) Chevalier and Ziziphus jujube Mill. as main raw material, the medicine-food homologous foods, and fermentation process of it was optimized through single factor experiments and response surface test, as well as its antioxidant capacity in vitro was measured. The results showed that the best fermentation technology parameter were as follows: Malus doumeri (Bois) Chevalier juice and Ziziphus jujube Mill. juice mass ratio was 1:2, with initial sugar content 21°Bx, yeast inoculum 0.3%, fermentation temperature 19 ℃, SO₂ addition 55 mg/L, and fermentation time 7 d. On this condition, the compound fruit wine was light yellow with mellow body and no impurities, provided with the unique fragrance of Malus doumeri (Bois) Chevalier and Ziziphus jujube Mill., both refreshing and pleasant. The alcohol content of compound fruit wine was 11.50%vol±0.10%vol, the soluble solid content was 7.80%±0.08%, the sugar content was 3.40±0.13 g/L, the acid content was 7.13±0.03 g/L, the extraction content was 22.40±0.15 g/L, the SO₂ content was 0.074±0.006 g/L, the sensory score was 93.80±0.40, and its physicochemical and hygiene indicators reached the national standard of fruit wine. Meanwhile, the maximum scavenging capacity of DPPH· and ABTS⁺· could reach 85.7% and 88.8%, respectively, and the antioxidant capacity was significantly higher than that of compound juice, but less than that of vitamin C. The compound fruit wine developed by this study has a unique flavor and a good specific antioxidant activity, which would provide a scientific basis for the development and application of Malus doumeri (Bois) Chevalier and Ziziphus jujube Mill.