Optimization of fermentation technology and antioxidant activity of Astragalus memeranaceus and Codonopsis pilosula health rice wine by fuzzy mathematics evaluation and response surface method

In this study, a health rice wine was developed with glutinous rice as the main raw material, with addition of Astragalus memeranaceus and Codonopsis pilosula extract, and with sweet wine koji as the starter. The fermentation process of A. memeranaceus and C. pilosula health rice wine was optimized by single-factor experiments, fuzzy mathematics evaluation and response surface method, and its antioxidant activity was studied. The results showed that the optimal fermentation process of A. memeranaceus and C. pilosula health rice wine was as follows: based on the quality of glutinous rice, water addition 80%, fermentation temperature 30 ℃, fermentation time 48 h, wine koji addition 0.3%, A. memeranaceus extract addition 4%, C. pilosula extract addition 15%. Under these optimal conditions, the sensory score of the rice wine was the highest (90.8), it was light yellow, sour and sweet, the taste of the wine had the fermented flavor of rice wine, and had the light aroma of A. memeranaceus and C. pilosula. After dealcoholization,the alcohol content of the rice wine was 0.39%vol, the total acid content was 0.212 g/100 g, the reducing sugar content was 26.21 g/100 g, the pH was 4.52, the soluble solid content was 15.7 g/100 g, the insoluble solid content was 39.7 g/100 g, and the total flavonol content was 217.2 mg/L, the polyphenol content was 68.2 mg/L, coliform group was not detected, and the total number of colonies was 21 CFU/g, the physicochemical and microbial indexes met the relevant standards. The half inhibitory concentration (IC50) values against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals of the rice wine were 158.9 mg/L and 170.5 mg/L, respectively, indicating that the rice wine had certain antioxidant capacity.