Unraveling the Microbial Associations of Volatile Flavor Profiles in Spontaneously Fermented Camel Milk from Three Regions of Xinjiang, China

Spontaneously fermented camel milk from Xinjiang is valued for its nutrition but faces quality inconsistency due to complex microbial ecosystems. This study investigated how regional microbial communities correlate with volatile flavor profiles. Nine samples from three distinct areas—Dabancheng, Hami, and Keping—were analyzed using bacterial 16S rRNA gene and fungal ITS region amplicon sequencing combined with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-TOF MS). Bacterial communities were dominated by Firmicutes and Proteobacteria, while Ascomycota and Basidiomycota prevailed among fungi. Dominant genera varied by region: Lactobacillus and Dekkera in Dabancheng; Lactobacillus and Dipodascus in Hami; Lactococcus and Cutaneotrichosporon in Keping. Flavor profiles also diverged, with Dabancheng being rich in esters, alcohols, and ketones; Hami featuring hydrocarbons and alcohols; and Keping containing elevated hydrocarbons, alcohols, and esters. Key statistical associations were identified: Lactobacillus, Rahnella, and Acetobacter were positively associated with propene and 3-decyn-2-ol (VIP > 1.0, |r| > 0.8), while Pseudomonas, Lactococcus, and Klebsiella showed negative correlations with vinyl n-caproate. These findings reveal statistical associations between geographic origin, specific microbial taxa, and flavor attributes, providing a scientific foundation that may inform future efforts toward developing targeted starter cultures pending microbial isolation and functional validation.