Gelation behaviour of fish skin gelatin in the presence of methanol‐water and ethanol‐water solvent system

Summary The aim of this study was to investigate the different concentrations of methanol and ethanol (5%‐40%, v/v) on the gel, rheological and structural properties of fish skin gelatin (FG). The results showed that lower contents of both methanol and ethanol (5%‐15%, v/v) increased gel strength, hardness and chewiness of FG gels. Rheological results showed that the viscosity of methanol‐water‐induced FG increased from 0.32 to 5.20 Pa·s with increased concentration of methanol, whereas an opposite trend was found for the ethanol‐water‐induced ones. Compared with ethanol‐water‐indued FG gels, methanol‐water‐induced gels present lower gelation times, and higher gel properties, because of the formation of more hydrogen bonds during gelation. Lower contents of methanol significantly unfold gelatin with the increase in β‐sheets. Finally, the mechanism of methanol‐ and ethanol‐induced FG gelation was updated. This research can serve as a guide for semi‐solid food which contains alcohol and medicinal products.