Comparison of bioaccessibility of astaxanthin encapsulated in starch-based double emulsion with different structures

In this study, different types of starch-based double emulsion (SDE) structures were developed to improve the bioavailability of astaxanthin (AST). Droplet size, microstructure, zeta potential of the AST-loaded SDEs were measured during in vitro digestion model. Compared with the C-type SDEs prepared with high amylose starch (HAS), the AST-loaded SDEs prepared using native corn starch of 5 wt% (B-type structure) and 7 wt% (A-type structure) presented small mean droplet diameters (MA = 11.18 ± 0.40 μm and 8.23 ± 0.37 μm, respectively) and were more stable after simulated gastric digestion. Furthermore, the lipid digestion products (free fatty acids) were studied after simulated intestinal digestion. Interestingly, the bioaccessibility (57.54 ± 1.88%) of AST-loaded SDEs prepared by HAS was six times higher than that of digested unencapsulated AST. Thus, SDEs were found to be suitable carriers for liposoluble nutrient delivery and bioavailability in foods, beverages, and nutraceuticals. •A-type astaxanthin (AST)-loaded starch double emulsion (SDEs) showed smaller size.•and B-type AST-loaded SDEs were more stable after simulated gastric digestion.•C-type AST-loaded SDE bioavailability was six times more than unencapsulated AST.•AST could be encapsulated in all SDEs without loss of antioxidant activity.