Comparative investigations of various modification methods on the gelling, rheological properties and mechanism of fish gelatin

In this study, & kappa;-carrageenan(& kappa;C) and Transglutaminase (TG) were used to modify fish gelatin (FG). Three types of modified gelatin groups FG-& kappa;C, FG-TG and FG-& kappa;C-TG were prepared. The results showed that the gel strength and textural properties of FG gels were greatly enhanced by & kappa;C modification and & kappa;C-TG complex modification, whilst pure TG modification weakened the gelling properties. And the pure 0.1 % & kappa;C modified FG had the highest gel strength and hardness, respectively. Rheological behavior showed that the complex modified FG samples had the highest viscosity, gelling points, melting points and G'& INFIN;. Fourier infrared spectra and LF-NMR analysis showed that & kappa;C and & kappa;C-TG modification respectively improved the contents of hydrogen and isopeptide that decreased the water mobility but stabilized the helical structure of gelatin gels. Fluorescence intensity showed that three types of modification decreased fluorescence intensity. While, the formation of aggregates and denser gel networks decreased in vitro digestibility of FG.

Automated summary

In this study, κ-carrageenan (κC) and transglutaminase (TG) were used to modify fish gelatin (FG). Three types of modified gelatin groups FG-κC, FG-TG, and FG-κC-TG were prepared. Results showed that κC and κC-TG complex modification greatly enhanced the gel strength and textural properties of FG gels, while pure TG modification weakened the gelling properties. The pure 0.1% κC modified FG had the highest gel strength and hardness. Rheological behavior indicated that the complex modified FG samples had the highest viscosity, gelling points, melting points, and G'∞.