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

## TL;DR

This study shows how vacuum distillation can speed up Rice-flavor baijiu production while improving its flavor profile.

## Contribution

Identifies optimal vacuum pressure (0.6–0.8 atm) for enhancing flavor while reducing distillation time.

## Key findings

- Vacuum distillation at 0.6 atm reduced processing time by 33.78% without lowering yield.
- 0.6–0.8 atm produced desirable floral and fruity esters, while lower pressures caused solvent-like notes.
- Branched-chain alcohols and esters responded differently to pressure changes.

## Abstract

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 0.6–0.8 atm exhibited floral/fruity esters vs. solvent notes from branched-chain alcohols at 0.2–0.4 atm.•Branched-chain and aromatic alcohols, and short-/long-chain esters showed distinct pressure responses.

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 0.6–0.8 atm exhibited floral/fruity esters vs. solvent notes from branched-chain alcohols at 0.2–0.4 atm.

Branched-chain and aromatic alcohols, and short-/long-chain esters showed distinct pressure responses.