Analysis of Fungal Communities of High-temperature and Medium-temperature Daqu in Binzhou Region and Their Correlation with Sensory Quality

To analyze the differences in fungal community structure and sensory quality of different types of Daqu in Binzhou, Shandong Province, the fungal community structure and quality characteristics of high-temperature and medium-temperature Daqu in Binzhou region were comprehensively analyzed by high-throughput sequencing, electronic nose and electronic tongue technology. The results showed that the diversity and richness of fungal species in high-temperature Daqu were significantly lower than those in medium-temperature Daqu (P<0.01), and there were significant differences in fungal community structure between the two types of Daqu (P<0.05). Among them, the average relative abundance of Thermomyces in high-temperature Daqu was significantly higher (P<0.05), while the average relative abundance of Aspergillus, Rhizopus, Rhizomucor, and Lichtheimia in medium-temperature Daqu were significantly higher (P<0.05). Thermomyces and Wickerhamomyces could be used as biomarkers for high-temperature and medium-temperature Daqu, respectively. And the stability of fungal microbial network in high-temperature Daqu was weaker than that in medium-temperature Daqu. In addition, there was no significant difference in flavor quality between the two types of Daqu (P>0.05), but the difference in taste quality was significant (P<0.01). Among them, the bitterness and umami-aftertaste were significantly lower in high-temperature Daqu (P<0.05), and the sourness, saltiness and bitterness-aftertaste were significantly lower in medium-temperature Daqu (P<0.05). And there was no significant correlation between the dominant fungal genera of Daqu and flavor indexes (P>0.05), but there was a significant correlation between the dominant fungal genera of Daqu and taste indexes (P<0.01). Among them, Thermomyces was positively correlated with sourness, astringency and bitterness-aftertaste and negatively correlated with umami and umami-aftertaste, while Aspergillus, Rhizopus, Rhizomucor, Rasamsonia, and Lichtheimia were the opposite. It can be seen that there were differences in fungal community structure and taste quality between high-temperature and medium-temperature Daqu in Binzhou region, and there was a correlation between dominant fungal genera and taste index.