Effect of ethanol on structures and properties of Japonica rice during heat-moisture treatment

JIANG Ruyi; ZHENG Xinyue; HUANG Sirong; DONG Ke; XIE Xiaoxiao; CHI Chengdeng

doi:10.12187/2025.06.002

Abstract：[Objective]To improve the food processing adaptability and practical value of Japonica rice.[Methods]Heat-moisture treatment(moisture content:25%)was used for the modification of Japonica rice.The effects of ethanol at 40%,80%,and 120%of the moisture content on structural properties(amylose content,morphology,crystalline structure)and functional properties(pasting properties,cooking loss,digestibility)were systematically investigated.[Results]Heat-moisture treatment significantly reduced the amylose content and A-type crystallinity,while promoting the formation of V-type crystalline structures.This enhanced thermal stability and reduced viscosity and cooking loss.The addition of ethanol did not alter the crystalline structure type but induced microstructural disruption,reducing A-type crystallinity while increasing amylose content and V-type crystalline formation.Moderate ethanol concentrations(40%～80%)caused greater disruption of A-type structures and promoted V-type crystallization,thereby improving thermal stability and rapidly digestible starch content while decreasing viscosity and cooking loss.At 120%ethanol concentration,A-type crystallinity remained stable but V-type crystalline formation decreased,leading to reduced thermal stability,increased viscosity and cooking loss,and elevated slowly digestible starch content.[Conclusion]The structural and functional properties of Japonica rice can be precisely modulated by controlling ethanol concentrations during heat-moisture treatment.