Enhanced thermal stability of anthocyanins through natural polysaccharides from Angum gum and cress seed gum

Abstract

Enhanced thermal stability of anthocyanins from black barberry was obtained using an optimum concentration of Angum gum (AG) and cress seed gum (CSG). To this goal initially, the phytochemical characteristics, and the thermal stability of purified and non-purified anthocyanins were investigated to perceive the effect of the purification process. Then the effect of each gum and its concentration was evaluated on the thermal degradation kinetics of anthocyanins. Results demonstrated that both gums enhanced the thermal stability of anthocyanins, while CSG had a superior effect. Findings also revealed that the half-life of anthocyanin was increased at 60°C from 366 ± 22.8 to 432 ± 4.2 and 636 ± 52.8 min in presence of AG and CSG, respectively. TGA results confirmed that the presence of SF-AG and CSG in their optimum concentration enhanced the heat stability of anthocyanin extract. Also, physical molecular bondings were confirmed by the FTIR spectrums where some peaks attributed to both of the extract and the gums were shifted. Plateau or flake-like micro-particles were detected by SEM which correspond with the most freeze-dried microcapsules. PRACTICAL APPLICATION: The results of this study may contribute to the enhanced thermal stability of anthocyanins from barberry that can be used as a coloring agent in beverage and food systems. Moreover, it can be used in preparation of natural nutraceuticals and pharmaceuticals.