Effect of Solid-state Fermentation on Antioxidant Properties of Wheat Bran and Sensory Quality of Whole Wheat Bread

Solid-state fermented wheat bran with Lactobacillus plantarum LB-1 and Saccharomyces cerevisiae was used to prepare whole wheat bread. The antioxidant properties of fermented bran and the sensory quality of whole wheat bread such as color, specific volume, texture, flavor and mouthfeel were analyzed. The results showed that the contents of total free amino acids, soluble protein, soluble polyphenols and soluble arabinoxylan in wheat bran increased by 1.44, 1.82, 2.67 and 2.68 times after 36 h mixed culture fermentation, respectively. The total reducing power, 1,1-dipheny1-2-picryl-hydrazyl (DPPH) radical and superoxide anion radical scavenging capacity increased by 1.88, 1.42 and 3.1 times, respectively. The L^* values of whole wheat bread crumb and crust with fermented bran decreased significantly as compared to those with unfermented bran. Moreover, addition of bran fermented for 36 h increased bran bread specific volume by 1.24 times, decreased significantly hardness, gumminess and chewiness, and cohesiveness and elasticity increased significantly, resulting in a more soft and palatable mouthfeel. In addition, solid-state fermentation of wheat bran produced 15 new volatile flavor compounds, and increased the contents of acetic acid and ethanol significantly, thus enhancing the flavor characteristics of whole wheat bread. The sensory score of whole wheat bread with bran fermented for 36 h was the highest. In conclusion, 36 h solid-state fermentation by Lactobacillus LB-1 and yeast effectively enhances the antioxidant activity in vitro of wheat bran, slows down the aging of starch in whole wheat bread and consequently improves texture properties including viscoelasticity as well as sensory attributes such as color, flavor and taste, and thus it has great application potential.