Flavor characteristics of rice-aroma baijiu under low, atmospheric, and high pressure distillation: a comparative...

This study systematically characterized the flavor characteristics of Rice-aroma Baijiu under low, atmospheric, and high pressure distillation using QDA, E-nose, HS-GC-IMS, and HS-SPME-GC-MS. Sensory evaluation indicated that low-pressure spirits were characterized by pronounced rice, grassy, and sweet notes, whereas high-pressure spirits displayed more prominent floral and honey notes; the atmospheric-pressure spirit presented a well-balanced flavor profile. The E-nose clearly discriminated samples obtained under different pressures. A total of 248 volatile compounds were identified by HS-GC-IMS and HS-SPME-GC-MS combined (with 19 shared by both), comprising 82 esters, 29 alcohols, 28 aromatic compounds, 20 aldehydes, 15 terpenes, 10 acids, and others. PLS-DA screened 47 key differential volatiles (VIP > 1, P < 0.05). High-pressure spirits contained the highest proportion of esters, while atmospheric distillation favored alcohols. ROAV-based screening identified ethyl isobutyrate, ethyl caprylate, limonene, Isoamyl acetate, ethyl 2-methylbutyrate, isoamyl propionate, and isoamyl butyrate as key aroma compounds. The mantel test revealed a significant positive correlation (P < 0.05) between Isoamyl acetate and Ethyl 2-methylbutyrate and grassy, sweet, and rice notes in low-pressure samples. Conversely, limonene, Isoamyl propionate, and isoamyl butyrate were associated with fruity and floral characteristics in high-pressure samples. These findings provide a scientific basis for flavor design and quality enhancement of Rice-aroma Baijiu.