Release and Bioaccessibility of β‑Carotene from Fortified Almond Butter during in Vitro Digestion

The objective of this study was to determine the release and bioaccessibility of β-carotene from fortified almond butter using in vitro digestion models. Two types of fortifiers were investigated: β-carotene oil (oil) and whey protein isolate (WPI)-alginate-chitosan capsules containing β-carotene oil (capsule). Shaking water bath and Human Gastric Simulator (HGS) digestion models assessed the impact of gastric peristalsis on the release of β-carotene. Bioaccessibility of β-carotene was measured as percent recovered from the micelle fraction. There was greater release of β-carotene from oil fortified almond butter in the HGS model (87.1%) due to peristalsis than the shaking water bath model (51.0%). More β-carotene was released from capsule fortified almond butter during intestinal digestion. However, more β-carotene was recovered from the micelle fraction of oil fortified almond butter. These results suggest that a WPI-alginate-chitosan capsule coating may inhibit the bioaccessibility of β-carotene from fortified almond butter.