Abstract:

Studying the influence of water–ethanol mixtures on the properties of κ-carrageenan gels could serve as a tool for the development of innovative semi-solid alcohol-containing food products. The changes in κ-carrageenan gels upon immersion in solutions with various concentrations of ethanol were characterized. κ-Carrageenan gels immersed in high ethanol concentrations lost considerable weight. At lower ethanol concentrations (50%–70%), weight loss was only moderate. However, at ethanol concentrations lower than 50%, the gels swelled and gained weight. The swelling/deswelling of κ-carrageenan gels immersed in ethanol solutions was dependent on their hydrocolloid concentration. All gels became stronger with increasing concentration of ethanol in the surrounding solvent. This change in gel strength following immersion did not stem solely from the changes in hydrocolloid concentration upon swelling/deswelling. Cryo-scanning electron microscopy of the gels revealed microstructures consistent with the observed mechanical properties. The residual potassium concentration in gels immersed in the various ethanol solutions was found to be lower than that required for gelation, constituting possible evidence of changed interactions upon immersion. © 2017 Elsevier Ltd

Publisher's Version