Improved color stability of anthocyanins in the presence of ascorbic acid with the combination of rosmarinic acid and xanthan gum.

This study investigated the protective effect and mechanism of action of combined use of rosmarinic acid (RA) and xanthan gum (XG) on the stability of anthocyanins (ACNs) in the presence of l-ascorbic acid (pH 3.0). The addition of RA and XG, alone and in combination, significantly enhanced the color stability of ACNs, and the combined use of RA and XG showed the best effect. FTIR, 1H NMR, AFM and computational molecular simulation analyses revealed that the improvement in ACN stability following the combined addition of RA and XG was due to intermolecular interactions such as hydrogen bonding and van der Waals forces. In the ACN-RA-XG ternary complexes, XG had stronger binding interactions with ACNs than RA. Our findings provide a valuable potential to enhance the stability of ACNs in the presence of ascorbic acid with the combined use of RA and XG.