“Nanoencapsulation of astaxanthin using gum arabic and whey protein isolate as wall materials: Characterization and invitro release kinetics”

Astaxanthin (AST) has various biological activities, such as antioxidant, antitumor, and anti-inflammatory, but poor water solubility, instability, and low bioaccessibility greatly limit the development of its industrial application. Nanoencapsulation offers an effective method to enhance AST's stability and bioavailability. This study investigated the nanoencapsulation of AST from Xanthophyllomyces dendrorhous using gum arabic (GA), whey protein isolate (WPI), and GA/WPI complex as wall materials. The nanoemulsions were characterized for viscosity, droplet size and zeta potential. Analyses also included nanoencapsulated powder properties, encapsulation efficiency, encapsulation yield, FTIR, thermal stability, morphology and invitro release kinetics. Parameters such as viscosity, droplet size and zeta potential showed significant differences (p ≤ 0.05) among various nanoemulsions. The moisture content and water activity were in the range of 3.95–6.23 % and 0.32–0.35, respectively, which is suitable for long-term storage. The best results were achieved in GA/WPI-AST, where it had the highest encapsulation efficiency (90.31 %). FTIR revealed that the AST was well encapsulated in the nanocapsules. The results of DSC showed that the encapsulated AST changed from a crystalline state to an amorphous state. Nanocapsules displayed controlled release under simulated gastrointestinal conditions, and all the data showed good correlation with Korsmeyer-Peppas model kinetics.