TABLE 1.

Microbial and flavor characteristics of various baijiu types.

Classification	Microbial characteristics	Flavor characteristics	References
Maotai-flavored baijiu	Filamentous fungi (Aspergillus), Yeast (Pichia), and Bacteria (Bacillus); Bacteria are most numerous; mold species are the most abundant.	Phenolic compounds: tetramethylpyrazine and syringic acid; high content of organic acids, aldehydes, ketones, alcohols, amino compounds, pyrazine, furans, and nitrogen compounds.	Xiong, 2005; Bokulich et al., 2012; Cai et al., 2019
Strong-flavored baijiu	Aroma-producing yeasts, bacteria, and molds; Bacteria mainly include Bacillus, Streptomyces, Lysinobacter, Staphylococcus, Lactobacillus, Brevibacterium, and Brevibacterium	mainly ethyl caproate, followed by ethyl acetate, ethyl lactate, ethyl butyrate and ethyl caproate	Wang et al., 2011; Bokulich et al., 2012
Light-flavored baijiu	Bacteria: Bacillus and Lactobacillus; Yeast: Pichia thermophilus, Saccharomyces cerevisiae, and Isacchinia orientalis	Aromatic compounds: ethyl acetate; esters, acids, alcohols, phenolic compounds; the main flavor substances are ethyl acetate, followed by ethyl lactate.	Sun et al., 2021; Tang et al., 2022
Rice-flavored baijiu	Bacteria: Lactobacillus, Welchiella, Lactococcus, Acetobacter, mainly Lactobacillus; Fungi: Rhizopus. Yeast: Pichia anomala, Saccharomyces cerevisiae, and Issatchenkia orientalis	Phenyl ethanol in equilibrium with ethyl acetate and ethyl lactate	Wu et al., 2019; Huang et al., 2020; Hu Y.L. et al., 2021
Miscellaneous-flavored baijiu	Bacteria: Bacillus and Lactobacillus; Fungi: Paecilomyces, Saccharomyces, and Zygomycetes	High concentrations of ethyl lactate, 2,3-butanediol, and ethyl hexanoate, followed by heptanoic acid, ethyl heptanoate, isoamyl acetate, octane, isobutyric acid, and butyric acid	Huang et al., 2021
Feng-flavored baijiu	Naumovozyma, Rhizopus, Thermoascus, Aspergillus, Candida, Pseudeurotium, Saccharomycopsis, Pichia, Saccharomyces, Lactobacillus, Bacillus, Pediococcus, and Streptomyces, among which Naumovozyma and Lactobacillus are dominant	Ethyl acetate, ethyl hexanoate, and isoamyl alcohol	Wang, 2008; Chen et al., 2020; Huang et al., 2021
Te-flavored baijiu	The dominant strains are Saccharomyces, Pichia, and Galactomyces	High concentrations of ethyl acetate and ethyl hexanoate, followed by ethyl propionate, ethyl valerate, ethyl heptanoate, and ethyl nominate	Li et al., 2017; Fu et al., 2021
Sesame-flavored baijiu	Mold, yeast, and bacteria	Sulfur compounds: dimethyl disulfide, trithiodimethyl, 3-(methylthio) propanal, furfural mercaptan, and furfural disulfide	Tamura et al., 2010, 2011
Laobaigan-flavored baijiu	Mold, yeast, and bacteria	Esters: ethyl acetate, ethyl lactate; low content of ethyl acetate, ethyl butyrate, palmitate, and linoleic acid	Fan Q. et al., 2019; Cui et al., 2020
Chi-flavored baijiu	B. licheniformis, B. subtilis, etc.	Acetic, lactic or butyric acid, etc.	Li et al., 2016; Cui et al., 2020
Fuyu-flavored baijiu	Bacteria: Lactobacillus, Welbachia, and Bacillus; Fungi: Rhizopus, Candida, Pichia, and Aspergillus.	Aromatic compounds: ethyl caproate, ethyl lactate and ethyl acetate	Kang et al., 2021