Total phenolics content and antioxidant capacities of microencapsulated blueberry anthocyanins during in vitro digestion

The goal of this research was to investigate the change in phenolics content and antioxidant capacity of microencapsulated anthocyanins (ACNs) digested in vitro. Blueberry ACN microcapsules were prepared from two wall materials (whey protein isolate and gum arabic) and ACN powder, previously extracted with three solvent systems (acetonic, ethanolic, methanolic); this was then spray-dried. The physicochemical properties and release characteristics of the microcapsules were evaluated. Rehydrated gum arabic microcapsules retained more total ACNs but less ferric reducing power than did whey protein microcapsules. Ethanolic extracts retained most of the total ACNs while methanolic extracts possessed the highest antioxidant capacity. During in vitro digestion, gum arabic microcapsules had high release rates of phenolics with high antioxidant activity during the gastric phase. Whey protein microcapsules had comparably lower release rates but high antioxidant activity throughout digestion.