Analysis of fungal community structure in different stratified during stacking of sauce-flavor baijiu

The stacking fermentation process plays a vital role in the production of jiang-flavor baijiu.The aim of this paper is to elucidate the effect of environmental variables on the fungal communities at different stratified during the stacking of zaopei and the changes in volatile flavour substances during this process.The composition of fungi community in different stratified during stacking fermentation was analyzed. Principal coordinate analysis (PCoA) showed that there were significant differences in fungal community structure at different stratified in the late stacking fermentation period.The dominant fungal communities of different stratified of zaopei differentiated significantly with the stacking fermentation process.IncludingThermoascus,Thermomyces and Issatchenkia.Hexadecanoic acid ethyl ester had the highest concentration both surface layer and inner layer.The total content of flavoring substances in the surface layer of zaopei is higher, but the types of flavoring substances are less than in the inner layer.The relationship between temperature, moisture content, acidity, starch content and reducing sugar content and microbial community was analyzed by Redundancy analysis.The results showed that the correlation between microbial communities and physicochemical indexes in different stratified of zaopei was different, and acidity was strongly correlated with the microorganisms in zaopei.Spearman correlation coefficient revealed the correlation between fungal community and volatile flavor substances, and the results showed that microorganisms in different positions of zaopei might have different correlations with flavor substances.This study is helpful to understand the evolution of fungal community during stacking of sauce-flavor liquor and its relationship with environmental variables and volatile flavor substances.