Synergistic Effects of Sodium Alginate and Locust Bean Gum on Short- and Long-term Retrogradation of Mung Bean Starch

Abstract

In this study, sodium alginate (SA), locust bean gum (LBG) and mung bean starch (MBS) were used as raw materials. Dynamic rheometer, texture analyzer, differential scanning calorimeter, X-ray diffractometer and low-field nuclear magnetic resonance were used to explore the effects of SA, LBG and SA-LBG mixtures with different compounding ratios on MBS aging and their influence mechanisms. The results showed that adding SA, LBG and SA-LBG mixture can reduce the hardness, aging enthalpy value, recrystallization rate constant (k), relative crystallinity and water mobility of aged MBS gel, and increase its loss factor. Low-field NMR results found that the SA-LBG mixture increased the T2 of MBS gel. The results show that SA, LBG and SA-LBG mixture can delay the aging of MBS gel, among which the anti-aging effect of SA-LBG mixture is more significant. SA-LBG mixture at mass ratio of 1:1 exhibited a strongest synergistic effect on inhibiting MBS gel retrogradation. This may be due to that the synergistic effects between SA and LBG, as well as hydrogen binding among SA, LBG and starch, which could prevent interactions between starch molecules and inhibit starch recrystallization. These findings might provide useful information for improving MBS-based products’ shelf-life with introduction of SA-LBG.

Keywords

• mung bean starch
• retrogradation
• sodium alginate
• locust bean gum
• synergistic effects