Enhancing the Stability of Strawberry Anthocyanins Complexed to β-Cyclodextrin and Starch toward Heat, Oxidation, and Irradiation

Abstract

The instability of anthocyanins limits their application in food supplementation and in the food industry. Stabilities of strawberry anthocyanins (AN) were improved by complexation with both β-CD and starch against heat, H₂O₂, light, and UV irradiation. The stability of AN against H₂O₂ (2.21 mM) dropped (<20%) in 6 h but was enhanced in β-CD (49.32%) and starch (96.84%) complexes. Under light conditions, AN in the solid and solution (3.88 g/100 mL) forms degraded to 36.49 and 11.11%, while β-CD and starch complexes displayed stabilities of 98.20 and 91.76%, respectively, after 60 days. Under UV irradiation, AN showed similar instability where both AN forms expressed stabilities of 36.75 and 66.18%, respectively, after 168 h, while β-CD and starch complexes exhibited 51.13 and 40.10%, respectively. LC-MS-ESI showed that photoirradiation of both destroyed the full conjugation of the flavylium ring of the major components, pelargonidin and cyanidin hexoses; the mechanism was proposed. Docking binding models of major AN components in β-CD were obtained.