Abstract:The optimal production process and formula of hemp seed milk was determined through single factor and response surface experiments using the fuzzy comprehensive evaluation method, with cooked hemp seed milk as the raw material, the lactic acid bacteria mixture ratio, amount of added strain, fermentation temperature and fermentation time as the independent variables, as well as the number of viable bacteria, acidity and sensory score as the evaluation indicators. Experiments show that the fuzzy comprehensive evaluation value was the highest (0.927 points), with the number of viable bacteria, acidity and sensory score being 1.9×108 CFU/mL, 78 oT and 8.74 points, respectively, under the following conditions: ratio of Bulgarian lactobacillus: Thermophilic streptococcus: Lactobacillus casei: Streptococcus acidophilic, 2:2:1:1.78; inoculation quantity, 6.21%; fermentation temperature, 39.42 ℃; fermentation time, 7.12 h. After fermentation, the contents of total sugars and total solids in the hemp kernel milk were 69.29 mg/mL and 6.08±0.22 g/100 g, respectively, which were significantly lower than those before fermentation (p<0.05). The contents of total acids, total phenolics and total flavonoids were 7.99±0.34 mg/mL, 28.04±0.82 mg GAE/100 mL and 27.11±1.34 mg GAE/100 mL, respectively, which were significantly higher than those before fermentation (p<0.05). The antioxidant activity experiments showed that when the DPPH free radical scavenging rate and ABTS+ free radical scavenging rate were 50%, the concentrations of hemp seed milk after fermentation were 26.09 mg/mL and 7.22±0.13 mg/mL, respectively, which were equivalent to 0.25 mg/mL and 0.13 mg/mL tocopherol, and the antioxidant activity increased significantly (p<0.05).
