Work

Gravity shapes fermentation dynamics and volatile compound profiles in no-cook rice wine: A multi-criteria approach

Year: 2026

Type: article

Abstract: The energy-saving no-cook simultaneous liquefaction, saccharification, and fermentation (SLSF) process couples starch hydrolysis with yeast fermentation, but the influence of substrate loading on fermentation dynamics and volatile composition remains poorly characterised. This study investigated three gravity levels — 200, 270, and 311.5 g/L (NC1–NC3)—using Saccharomyces cerevisiae Ethanol Red and commercial raw-starch-hydrolysing enzymes. Fermentation reached practical completion at 72, 96, and 120 h, respectively, with ethanol concentrations increasing from 91.5 to 138.1 g/L. Increasing gravity significantly decreased completion-based ethanol productivity and sugar consumption rate, whereas ethanol yield and cell-normalised sugar consumption did not differ significantly among conditions. HS-SPME–GC–MS tentatively identified and semi-quantified 109 volatile compounds. PCA and HCA revealed marked gravity-associated differentiation of volatile composition, with NC2 showing the highest total volatile concentration and ester/alcohol ratio. MFA indicated treatment-associated co-variation between fermentation performance and volatile composition (RV = 0.749), which was stable under treatment-stratified bootstrap resampling (median RV = 0.758; 95% CI: 0.742–0.782). However, exact within-treatment permutation after treatment centering showed no additional replicate-level correspondence (RV = 0.494; p = 0.764), indicating that this co-variation primarily reflected between-gravity differences. Multi-criteria desirability analysis ranked NC2 highest under both geometric and arithmetic aggregation and across all criterion subsets tested. Overall, 270 g/L provided the highest-ranked compromise among the three tested conditions for the selected fermentation and chemical criteria, without implying a universal or sensory optimum.

Source: LWT

DOI: 10.1016/j.lwt.2026.119964