Multistarter fermentation of glutinous rice with Fu brick tea: Effects on microbial, chemical, and volatile compositions

Abstract

A higher fermentation efficiency was achieved, using multistarter fermentation of glutinous rice supplemented with Fu brick tea (FGR-FBT), than when using traditional fermentation. The effects of multistarter fermentation on the microbial, chemical, and volatile compositions were determined. When FBT was incorporated during glutinous rice fermentation, increased population of yeasts and fungi, as well as enhanced α-amylase, proteinase and β-glucosidase activities, were observed. Specific fungi were isolated and identified as Aspergillus spp., which are known to secrete extracellular enzymes that modify the chemical properties, including ethanol levels, pH, total acids, and total soluble solids. The aroma profile of fermented glutinous rice was studied in the absence and presence of FBT, using HS-SPME-GC-MS and the electronic-nose. This analysis indicated that 35 characteristic volatile compounds were only found in FGR-FBT. The results show that FBT can be added during the fermentation of food products to enhance microbial biotransformation and modify flavour metabolism.