Blackberry anthocyanins: β-Cyclodextrin fortification for thermal and gastrointestinal stabilization

Anthocyanins are potential food colorants due to their color, low toxicity and biological properties. However, the low chemical stability of anthocyanins has limited their use. In this work, the thermal stability of cyanidin-3-O-glucoside (cy3glc) (major blackberry anthocyanin) and blackberry purees through molecular inclusion with β-cyclodextrin (β-CD) was assessed. Complexation with β-CD showed a thermal stabilization of cy3glc, resulting on a decrease of the degradation rate constant (k) and in several alterations in the cy3glc-β-CD DSC thermogram. To assess the bioaccessibility of blackberry anthocyanins, the stability of blackberry purees through simulated in vitro digestion was also studied. Despite the rapid degradation of anthocyanins observed within the first minutes of simulated intestinal digestion, complexation with β-CD allowed anthocyanins degradation to be slowed down. The results obtained demonstrate the ability of β-CD to increase blackberry anthocyanins thermal stability and also to decrease the rate of degradation of these pigments under simulated gastrointestinal conditions.