Exploring the influence of vacuum distillation on volatile profile and sensory characteristics of Rice-flavor baijiu

This study assessed the effects of vacuum distillation (0.2, 0.4, 0.6, 0.8 atm) versus atmospheric distillation on Rice-flavor Baijiu . Distillation time was maximally reduced by 33.78 % at 0.6 atm without reducing yield. Fifty-four VOCs were identified, nineteen and thirteen with OAVs >1 in high alcohol ( HAR ) and low-alcohol ( LAR ) raw Baijiu samples, respectively. Branched-chain alcohols exhibited negative pressure correlation, whereas aromatic alcohols showed positive correlation. Short-chain esters fluctuated in HAR but correlated positively in LAR , while long-chain esters exhibited the reverse pattern. Integrated analysis of total acid/ester content, and total OAVs of desirable and undesirable compounds identified 0.6 and 0.8 atm as the optimal pressure. HAR and LAR fractions distilled at 0.6 and 0.8 atm exhibited floral , fruity , and sweet via ester correlations, while 0.2 and 0.4 atm fractions developed solvent from branched-chain alcohols. The results elucidate volatile behavior characteristics under varying vacuum conditions, guiding optimization in Rice-flavor Baijiu production. • Vacuum distillation above 0.6 atm significantly reduced processing time while maintaining atmospheric yield. • Integrated analysis identified 0.6 and 0.8 atm as the optimal vacuum for Rice-flavor Baijiu . • Distillates at 0.6 and 0.8 atm exhibited floral and fruity notes from esters, while 0.2 and 0.4 atm distillates developed solvent-like notes from branched-chain alcohols. • The study identified distinct pressure-response patterns among branched-chain alcohols, aromatic alcohols, short-chain esters, and long-chain esters during distillation.