Stability and bioavailability of protein matrix‐encapsulated astaxanthin ester microcapsules

Astaxanthin ester derived from Haematococcus pluvialis is often used as a functional and nutritional ingredient in foods. However, its utilization is currently limited as a result of its chemical instability and low bioavailability. Food matrix microcapsules are becoming increasingly popular because of their safety and high encapsulation efficiency. In the present study, the effect of protein matrixes on the properties of microcapsules was evaluated.We investigated the effects of storage on astaxanthin ester microcapsules and the corresponding rehydration solution at 40 °C under a nitrogen atmosphere, as well as in darkness. The results showed that the stability of products prepared based on whey protein (WP) and corn-gluten was superior to that of products prepared based on lactoferrin, soy protein and sodium caseinate. The bioavailability of astaxanthin ester microcapsules encapsulated with different proteins and examined by means of astaxanthin concentrations in the serum and liver after oral administration was compared. All five protein wall materials could significantly improve the bioavailability of astaxanthin ester. The microcapsules prepared based on WP had the highest bioavailability, with a value of 10.69 ± 0.75 μg·h mL-1 , which was 3.15 times higher compared to that of the control group.The results of the present study showed that protein encapsulation, especially WP encapsulation, could effectively improve the stability, water solubility and bioavailability of astaxanthin esters. Thus, WP can be used as the main wall material in delivery systems. © 2021 Society of Chemical Industry.