Potato protein- based carriers for enhancing bioavailability of astaxanthin

Astaxanthin (AX) is a potent - but highly lipophilic antioxidant, to which many health benefits are attributed. AX consumption was associated with reduced risk for cancer, cardiovascular diseases, neurodegenerative disorders and more. However, our diet is generally poor of astaxanthin, which is mainly found in certain algae, salmon and crabs. AX is sensitive to oxidation and has very low bioavailability. It is produced by cultivation of the microalga Haematococcus Pluvialis, which contains about 6% AX (dry weight). Herein we evaluated a potato protein (PP) based delivery system recently introduced by our lab, to test its potential for protecting AX and improving its solubility, bioaccessibility and bioavailability. PP is commercially isolated from a widely available and inexpensive food material, it has GRAS status and is not considered allergenic. We formed PP-AX nanoparticles (PP-AX NPs) by dropwise addition of AX, dissolved in ethanol, into PP in a phosphate buffered solution at pH 2.5. PP solubilized AX in the aqueous solution, and colloidally stable particles were obtained after freeze-drying and reconstitution. Following simulated gastric and intestinal digestion, 78% of the encapsulated AX was retained compared to only 23% of the unencapsulated AX. The bioaccessibility of entrapped AX was 11 times higher than that of unencapsulated AX. In-vitro bioavailability, studied using a Caco-2 cell model, was 7 fold higher than that of digested unencapsulated AX. These results highlight the great potential of PP in solubilization, protection, and bioavailability improvement of lipophilic bioactives, such as AX, for food and dietary supplements.