Analysis of the correlation between microbial community succession and volatile flavor compounds during the...

Traditional Qula, a distinctive dairy product from the pastoral areas of the Qinghai-Tibetan Plateau, derives its characteristic flavor primarily from microbial activity during production. To elucidate the relationship between core microorganisms and flavor formation during Qula preparation, this study employed high-throughput sequencing and gas chromatography-mass spectrometry (GC-MS) to analyze microbial diversity and flavor compounds throughout the process. Distinct, stage-specific flavor compounds were identified: fermentation (styrene, 3-hydroxy-2-butanone, myristic acid); hanging (phenethyl acetate, n-nonanoic acid); and sun-drying (n-nonanoic acid, n-decanoic acid, caprylic acid). Microbial diversity analysis revealed stage-specific dominant genera: Acetobacter, Lactobacillus, and Saccharomyces during fermentation; Acetobacter, Lactobacillus, Rhodotorula, Papiliotrema, and Kluyveromyces during hanging; and Leuconostoc, Lactococcus, and Apiotrichum during sun-drying. Furthermore, Spearman correlation analysis identified Lentilactobacillus, Lactococcus, Leuconostoc, Debaryomyces, and Saccharomyces as core functional microorganisms significantly correlated with the formation of characteristic flavor metabolites. These results provide a crucial theoretical basis for optimizing the Qula production process and improving its flavor quality.