Effect of Solid-state Fermentation on the Physico-chemical Properties of Wheat Bran

Abstract

Saccharomyces cerevisiae (S. cerevisiae) and Lactobacillus plantarum (L. plantarum) were used in separate and mixed for solid-state fermentation (SSF) of wheat bran (WB). Effects of SSF on the physicochemical properties of WB and dietary fiber content and composition were determined, and the correlation between various indicators was analyzed. Accordingly, the possible reasons of SSF improving nutrition and processing qualities of WB were preliminary explained, which is to the benefit of expanding the utilization of SSF in whole grain processing. Results showed that soluble dietary fiber (SDF) and arabinoxylan content of the fermented WB increased by 40.6% and 15.2%, respectively. WB fermented with a mixture of S. cerevisiae and L. plantarum had the highest water- and oil-holding capacity. SSF significantly decreased the peak denaturation temperature (TP), enthalpy, and crystallinity of WB from 195.35 ℃, 3 869.50 J/g, and 15.86% to 178.30 ℃, 3 276.67 J/g, and 15.24%, respectively (P<0.05). Correlation analysis results showed that SDF content in WB had a remarkable negative correlation with crystallinity and TP, with the correlation coefficients of –0.959 47 and –0.950 7, respectively. After SSF, structure of WB changed from intact and compact to loose and dispersed one, and the clarity and uniformity of plant cells were significantly reduced. In conclusion, SSF reduces the density of the internal tissue structure of WB due to the metabolism of the microorganisms, which was not only beneficial to the release of bioactive components, but also significantly improved its processing qualities.

Keywords

• wheat bran
• soli-state fermentation
• dietary fiber
• physic-chemical property
• correlation analysis