Characterization of food gels prepared from the water extract of fish (Cyprinus carpio L.) scales: From molecular components to sensory attributes

Food gels prepared from the water extract of fish scales (WEFS) are described in this study. The effects of WEFS, sucrose, and NaCl concentration on gel formation and stability, gel texture, and gel sensory attributes were evaluated. The results indicated that an increase in WEFS concentration led to increases in the formation rate, stability, and texture of the gel. Addition of a moderate amount of sucrose (2%–3%, w/v) and NaCl (0.4%–0.6%, w/v) improved the stability, gumminess, chewiness, and cohesiveness of the gel. However, the addition of an excessive amount of sucrose (>4%, w/v) and NaCl (>0.8%, w/v) decreased the stability, gel strength, adhesiveness, and springiness of the gel. The sensory attributes of fish scales (FS) gels were mainly affected by WEFS concentration. On the basis of combined textural analysis and sensory evaluation, the FS gels formed with 4% WEFS, 3% sucrose, or 0.4% NaCl was proposed in this study. The gel microstructure and water distribution obviously showed an apparent variation, together with a change in the structure of FS gels. Competing hydrophilic forces and electrostatic interactions varied with sucrose and NaCl concentration, altering the structure and water distribution of FS gels.