The products from fermentation of wheat bran fiber by Auricularia polytricha strain and the effects of the products on rheological properties of dough sheet

Being classified within the Basidiomycota, Auricularia polytricha has been proved to degrade lignocellulose, a major component of wheat bran fiber. During the fermentation of lignocellulose by A. polytricha strain, a large number of intermediate products are produced, which affect the further degradation of lignocellulose. Therefore, it is essential to analyze the fermentation intermediates for study on the degradation mechanism of wheat bran fiber. In this study, the effectiveness of fermentation of wheat bran fiber by A. polytricha strain was confirmed via scanning electron microscopy. Additionally, the results of gas chromatography–mass spectrometry indicated that the A. polytricha strain could degrade wheat bran fiber and produce several aromatic compounds, and that the number of products obtained after 7 days of fermentation was significantly lower than that after 3 days of fermentation. It has also been demonstrated that diisooctyl phthalate and 9‐octadecenamide belong to metabolites produced during the fermentation of wheat bran fiber, by culturing A. polytricha with wheat bran fiber and glucose as carbon source, respectively. Moreover, by conducting an ultraviolet wavelength scanning of the culture liquid containing vanillin fermented by A. polytricha, it has been indicated that the strain could degrade vanillin and further demonstrated that the strain has the ability to degrade wheat bran fiber. Furthermore, adding the products of wheat bran fiber fermented for 3 days by A. polytricha could improve the elasticity of the dough sheet.