Characterization of Microbial Content, Antioxidant Capacity, and Volatile Compounds in Boza

This study investigated the microbial composition, antioxidant activity, and volatile aroma compound profiles of boza samples collected from six traditional producers in Türkiye. Lactic acid bacteria (LAB) counts ranged from 5.45 to 9.06 log CFU/mL, while yeast and total aerobic mesophilic bacteria (TAMB) levels varied significantly, reflecting differences in raw materials and fermentation conditions. Samples exhibiting higher LAB populations showed significantly enhanced antioxidant activity, underscoring the role of LAB metabolism in radical-scavenging capacity. Volatile aroma compounds were analyzed using HS-SPME/GC-MS, revealing substantial variation in aroma profiles among samples. Major compounds identified included 3-hexenoic acid, 2-undecenal, muconic acid, acetaldehyde, benzyl alcohol, and phenol. Samples with richer aroma complexity were associated with balanced LAB–yeast communities, whereas limited volatile diversity in certain samples was linked to distinct microbial compositions, including the presence of Bacillus spp. Overall, the findings demonstrate that boza exhibits a diverse microbiota and a complex, fermentation-driven aroma matrix shaped by microbial interactions and cereal-derived metabolites. These results emphasize the importance of microbial composition and controlled fermentation practices in enhancing product quality, sensory characteristics, and functional potential of traditional boza.