[6-1015-A] Functional/Wellness Foods & Nutrition (2)

[6-1015-A-04] Preparation of Pigment Extract Loaded Alginate Beads and Their Stability of Antioxidant Activities during in vitro Gastrointestinal Digestion

*Rungarun Sasanatayart¹, Sutthiwal Setha¹ (1. School of Agro-Industry, Mae Fah Luang University(Thailand))

Keywords:Anthocyanins , Carotenoids , Antioxidant , Alginate based Encapsulation , in vitro gastrointestinal digestion

Plant pigments are safe for food applications and exert antioxidant activities, providing health benefits superior to synthetic colorants. However, there are challenges related to color losses during food processing, storage, and commercialization due to a low stability of natural pigments. In addition, based on human gastrointestinal digestion, levels of bioactive compounds and their related antioxidant activities are significantly altered. One effective approach to preserve the health beneficial properties of plant pigments is to incorporate them into polymer matrices for the improvement of stability and bioavailability. In this study, 2.5% w/w pigment extracted from butterfly pea flower (BPF) and 5% w/w pigment extracted from turmeric rhizome (TR) were prepared. PBF and TR loaded alginate beads were prepared by extrusion method using 1%w/v alginate and 2%w/v calcium chloride (CaCl₂). To examine the stability through simulated gastrointestinal digestion, a certain amount of BPF and TR loaded alginate beads were either added into distilled water or formulated into juice model samples containing 10%w/v glucose and 0.1M citric acid. To assess effect of heat, all samples were adjusted to pH 3.0 and were subjected to pasteurization at 75^oC for 15 min. Samples without heat treatment were also compared. Samples were examined for antioxidant properties in terms of total anthocyanins content (TAC) for BPF, total carotenoids content (TCC) for TR, total phenol content (TPC), total flavonoid content (TFC) and antioxidant activities based on FRAP and DPPH assays. During in-vitro gastrointestinal digestion, samples showed different amount and stability of TAC, TCC, TPC, TFC and antioxidant activities based on FRAP and DPPH, regarding type of pigments. Results showed that alginate-based encapsulation of pigment extract limited the release of bioactive compound during in vitro gastrointestinal digestion. The effect of either pasteurized heat alone or in combining with ingredients in releasing more bioactive components of juice model samples was also noted. During in vitro gastrointestinal digestion, the high stability of bioactive compounds and antioxidant activities from oral phase (G0) to gastric phase (G30) but subsequently lower stability along intestinal phase (I0-I120) were observed in all samples. These stability data supports the beneficial effect of alginate-based encapsulation in controlled releasing of bioactive compounds of plant pigments and their bioavailability which could be further applied in food industry.