Abstract:

Response surface methodology was used to optimize fermentation condition to improve antioxidant activity in solidstate sesame cake by Aspergillus sojae. The effects of maltose, glucose, sucrose, fructose, wheat bran, corn steep, yeast extract and ammonium sulfate on scavenging capability of sesame cake to DPPH free radicals were evaluated by using Plackett-Burman design. Results showed that wheat bran and glucose as well as ammonium sulfate were the major factors and had significant effect on antioxidant activity. Meanwhile, the central composite experimental design and response surface analysis were used to optimize the levels of major factors. The optimal condition was 1.87% glucose, 1.54% ammonium sulfate and 2.55% wheat bran, respectively. Under this optimal fermentation condition, the scavenging capability of sesame cake to DPPH free radicals was 80.26%.

Key words: sesame cake, fermentation, optimization, antioxidant activity, Aspergillus sojae