The study of microbial diversity and volatile compounds in Tartary buckwheat sourdoughs

•Lactococcus and Weissella were the dominant LAB in Tartary buckwheat sourdoughs.•The yeasts in Tartary buckwheat sourdough were mainly Pichia and Wickerhamomyces.•Pyrazine compounds were the main volatile compounds in the Tartary buckwheat sourdough.•Tartary buckwheat sourdough fermented for 12 h is recommended, with better flavor.•Microbial diversity was the key factors to affect the flavor of Tartary buckwheat. Microorganisms play an essential role in forming volatile compounds in traditional staple products. Tartary buckwheat, as a medicinal and food material, has high nutritional value but its development and utilization are seriously restricted due to its poor flavor. In this study, 16S rRNA and ITS rRNA sequencing were used to analyze the microbial diversity of Tartary buckwheat sourdoughs, while HS-SPME-GC/MS was used to identify volatile compounds during fermentation. The results showed that Lactococcus and Weissella were the dominant bacterial genus. Wickerhamomyces, Penicillium, and Aspergillus were the main fungal genera in the Tartary buckwheat sourdoughs. And the main volatile compounds in Tartary buckwheat sourdough were pyrazine compounds. After 12 h of fermentation, a large amount of alcohol and esters were produced, which endowed the sourdough with a good flavor. This suggests that sourdough fermentation could significantly improve the flavor of Tartary buckwheat.