Structure-function relationship between galactomannans and their effects on freeze-thaw stability, retrogradation, and texture of corn starch gels during cold storage

In this study, structural characteristics of Fenugreek (FG), Guar (GG), Locust bean (LBG), and Tara gums (TG) and their influence on physicochemical properties of corn starch (CS) gels were investigated. Results showed that FG presented a rigid rod structure, and GG, LBG, and TG showed an extended structure. The Mannose/Galactose (Man/Gal) ratio of FG, GG, LBG, and TG was 1.37, 1.96, 2.99, and 3.46, respectively. The molecular weight (M-w) of FG, GG, LBG, and TG was 0.89 x 10(6), 2.71 x 10(6), 3.61 x 10(6), and 2.77 x 10(6) Da, respectively. The structure-function relationship indicated that galactomannans with a high Man/Gal ratio and extended structure presented a higher apparent viscosity, formed gel more easily, and could limit retrogradation and improve freeze-thaw stability and textural profile of CS gels. Consequently, the results could be beneficial for the application of galactomannans in starch-based foods to improve their sensory characteristics and storage quality.

Automated summary

This study investigated the structural characteristics of Fenugreek, Guar, Locust bean, and Tara gums and their impact on the physicochemical properties of corn starch gels. The results showed that Fenugreek had a rigid rod structure, while Guar, Locust bean, and Tara gums had an extended structure. The galactomannans with a high Mannose/Galactose ratio and extended structure exhibited higher apparent viscosity, easy gel formation, limited retrogradation, improved freeze-thaw stability, and enhanced textural profile of corn starch gels. These findings are important for improving the sensory characteristics and storage quality of starch-based foods when galactomannans are used.