Functional microbiota in Chinese traditional Baijiu and Mijiu Qu (starters): A review.
Sakandar Hafiz Arbab,Hussain Raza,Farid Khan Qaiser,Zhang Heping
Food research international (Ottawa, Ont.)
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, α-galactosidase, β-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.
Flavor mystery of Chinese traditional fermented baijiu: The great contribution of ester compounds.
Xu Youqiang,Zhao Jingrong,Liu Xiao,Zhang Chunsheng,Zhao Zhigang,Li Xiuting,Sun Baoguo
Chinese traditional fermented baijiu is a famous alcoholic beverage with unique flavor. Despite its consumption for millennia, the flavor mystery behind baijiu is still unclear. Studies indicate that esters are the most important flavor substances, and bring health benefits. However, the aroma contribution and formation mechanism of esters still need to be clarified to reveal the flavor profile of baijiu. This review systematically summarizes all the 510 esters and finds 9 ethyl esters contribute greatly to the flavor of baijiu. The 508 different microbial species that have been identified affect the synthesis of esters through fatty acid and amino acid metabolism. The determination of minimum functional microbial groups and the analysis of their metabolic characteristics are crucial to reveal the mechanism of formation of baijiu flavor, and ensure the reproducible formation of flavor substances.
Profiling the influence of physicochemical parameters on the microbial community and flavor substances of zaopei.
Zhang Mingzhu,Wu Xuefeng,Mu Dongdong,Xu Boyang,Xu Xianghui,Chang Qiang,Li Xingjiang
Journal of the science of food and agriculture
BACKGROUND:Strong-flavor baijiu is a traditional distilled alcoholic beverage with a long history in China. The fermented grains play a pivotal role in the production of baijiu. The purpose of this study was to evaluate and compare the microbiota and flavor substances present in fermented zaopei (ZP) from pits of different ages. High-throughput sequencing, headspace solid-phase microextraction gas chromatography-mass spectrometry, principal component analysis, community composition analysis, and redundancy analysis were used to analyze and evaluate the impact of environmental factors on microbial communities and flavor substances. RESULTS:Six genera of bacteria (e.g., Caproiciproducens, Syntrophaceticus, Sedimentibacter, Hydrogenispora, Pelotomaculum and Bacillus) and seven genera of fungi (Cladosporium, Debaryomyces, Dipodascus, Auxarthron, Cephalotrichum, unclassified Stachybotryaceae, unclassified Microascaceae and Cephalotrichum) notably affected the production of hexanoic acid (an important flavor compound). Moisture and alcohol content also had considerable effects on the production of the flavor compounds such as ethyl lactate, hexanoic acid, and ethyl hexanoate. The profiles of volatile compounds present in ZP were different between the aged and new pits; these profiles were mainly reflected in the concentration and types of alcohols, aldehydes, esters, and aromatic compounds. CONCLUSIONS:This paper provides a comprehensive overview of the physicochemical parameters, flavor substances, and microbial population distribution of ZP. Characterization of various ZP samples help to elucidate the fermentation mechanisms and offer a theoretical reference to control and enhance the quality of Baijiu. © 2021 Society of Chemical Industry.