Functional microbiota in Chinese traditional Baijiu and Mijiu Qu (starters): A review

Chinese traditional fermented foods have a very long and complex history. These fermented foods have fascinating characteristics. These are mainly produced by autochthonous fermentation, involving an autochthonous complex microbiota in these fermented products which confers amazing functional characteristics. These include desirable taste, aroma, texture, exopolysaccharides, alpha-galactosidase, beta-glucosidase, xylanase, antioxidants, and aglycone isoflavones which are produced along with other substances. Baijiu is a traditional Chinese spirit, which is widely consumed in East Asia, especially China, and is considered one of the most consumed spirits in the world. It is produced by autochthonously prepared traditional qu (starter culture), such as Xiaoqu, Daqu, Fuqu, and others. Microbial communities in various qu, thereof, have still not been properly characterized. There are several factors that contribute to microbial communities and to the final products of fermentation. This review shall succinctly describe recent scientific research on the production of flavor compounds by bacteria and fungi in Chinese traditional Baijiu qu (starter cultures), with special focus on the fungi and bacteria, and their functionalities with respect to flavor development in Baijiu.