Black bean coats: New source of anthocyanins stabilized by β-cyclodextrin copigmentation in a sport beverage

Anthocyanin-rich powders and aqueous extracts, with high antioxidant activities, were obtained from black bean seed coats and applied to colour a sport beverage. Idaho and Otomi bean coats were extracted in water-citric acid 2% (1/50, w/v), stirring for 4 h at 40 °C. Anthocyanins from Idaho and Otomi extracts (1.83 mg and 1.02 mg C3G/g, respectively) were applied to a commercially available sport beverage, with and without 2% β-cyclodextrin (βCD) under light and darkness conditions for 10 days, and stored at 4 °C and 25 °C for 6 weeks. At different light and storage conditions, anthocyanin degradation fitted a first-order reaction model. All bean coat anthocyanins combined with βCD showed extended half-life (up to 13 months), higher D-values (up to 43 months) and fewer differences in colourimetric properties (lightness, chroma and hue angle) under darkness and 4 °C conditions. These black bean coat aqueous extracts and powders might represent natural alternatives to synthetic colorants, ecologically extracted, and with a high antioxidant potential.