Optimization of fermentation technology of Panax quinquefolius-fig compound fruit wine by response surface methodology

Using Panax quinquefolius and fig as raw materials, yeast as fermentation strain, and P. quinquefolius-fig compound fruit wine was prepared. Based on the single factor test, the fermentation conditions of P. quinquefolius-fig compound fruit wine was optimized by response surface test with total ginsenosides and sensory scores as response values. The physicochemical, microbial indexes and antioxidant capacity were determined. The results showed that the optimal fermentation technology conditions were as follows: inoculum 0.05%, fermentation temperature 22 ℃, time 8 d, soak time of P. quinquefolius 24 h. Under these optimization conditions, P. quinquefolius-fig compound fruit wine had orange color, sweet and mellow, with a unique typical of P. Quinquefolius and fig, and sensory score was 83.7 points. The total ginsenosides content was 1.58 mg/ml, alcohol content was 11.52%vol, total acid was 6.09 g/L, total sugar was 43.20 g/L, total bacterial colony was 10 CFU/ml, and no Escherichia coli and pathogenic bacteria were detected. Its physicochemical and microbiological indexes were in line with the relevant standards. In addition, the free radical scavenging rate of 1,1-diphenyl-2-trinitrophenylhydrazide (DPPH) in P. quinquefolius-fig compound fruit wine was 93.25%, indicating that it had certain antioxidant capacity.