Ethanol-induced physical instability in turbid rice wine: Insights from the role of insoluble particle characteristics

• Ethanol significantly accelerated sedimentation and reduced long-term stability of turbid rice wine (TRW). • Higher alcohol by volume promoted particle aggregation and reduced the dispersibility of TRW. • Ethanol disrupted viscoelastic gel network of TRW system. • Alcohol enhanced starch-protein associations and induced V-type crystallinity in insoluble particles. Turbid rice wine (TRW) is a traditional Chinese low-alcohol beverage. However, the impact of ethanol in the system on its physical stability remains insufficiently explored. This study investigated the effects of alcohol by volume (ABV, 0-10%vol) on TRW stability and its insoluble particle characteristics. As ABV increased, the sedimentation rate rose from 13.2% to 15.5%, accompanied by significant particle size growth and weakened electrostatic interactions. Rheological analyses showed significant reductions in apparent viscosity, storage modulus (G′), and loss modulus (G″), indicating ethanol-induced disruption of the viscoelastic gel network. The instability index increased from 0.701 to 0.772, reflecting reduced long-term stability. Particle characteristics analyses revealed that starch dominated the insoluble fraction, and ethanol promoted the enrichment of starch and protein in insoluble particles, facilitating the formation of larger complexes and concurrent precipitation of soluble dextrins. Moreover, ethanol increased the short-range molecular order and V-type crystallinity of starch within insoluble particles, consistent with observed thermal behavior changes. Overall, ethanol destabilized TRW by altering particle interactions and structural organization. These findings clarify the underlying mechanisms of ethanol-induced instability and offer theoretical guidance for improving product quality.