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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Publications at this Location » Publication #429194
Research Project: Improving North American Atlantic Salmon Aquaculture Production

Location: National Cold Water Marine Aquaculture Center

Title: Comparative assessment of wall material combinations on the encapsulation of astaxanthin-rich weakened haematococcus pluvialis

Author
item ARYEE, ALBERTA - Delaware State University
item ONINKU, BECKHAM - Delaware State University
item NGUYEN, ANH - Delaware State University
item LOMAS, MICHAEL - Bigelow Laboratory For Ocean Sciences
item Burr, Gary

Submitted to: Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: rotecting oxygen-sensitive compounds contained in microalgae such as natural astaxantin (ASX) Haematococcus pluvialis (Hp), encapsulation can be an effective strategy to minimize degradation and improve bioaccessibility . This study aimed to evaluate the influence of different encapsulation materials; alginate (ALG) combined with one of the following five polymer wall materials: gum arabic (GA), lecithin (LEC), maltodextrin (MD), pectin (PEC), or whey protein concentrate (WPC) on their ability to protect the astaxanthgiuncontained in the algae. Encapsulating microalgae containing astaxanthin preserved antioxidant activity, decreased astaxanthin degradation during storage and increased accessibility when evaluated in the lab. Further studies are needed to determine if these effects remain when fed to living organisms and when incorporated into feed.

Technical Abstract: The encapsulation of the microalgae Haematococcus pluvialis (Hp), the main source of natural astaxanthin (ASX) is an effective strategy to minimize degradation and improve bioaccessibility. This study aimed to evaluate the influence of alginate (ALG) combined with one of the following five polymer wall materials: gum arabic (GA), lecithin (LEC), maltodextrin (MD), pectin (PEC), or whey protein concentrate (WPC) on the properties of hydrogels containing weakened Hp (Hpw) using ionic gelation. Encapsulation efficiency and loading capacity ranged from 97.05 to 98.52%, and 32.46 to 32.95%, respectively, with highest of both in ALG-WPC-Hpw. Significant differences were observed in color parameters, where ALG-WPC-Hpw displayed the most intense coloration. Confocal laser scanning microscopy showed homogenous Hpw distribution across all hydrogels, with rough textures, variable porosity and crack-free surfaces, while FTIR and DSC analyses confirmed successful encapsulation of Hpw. While all the wall material combinations enhanced thermal stability of Hpw by shifting the endothermic peak to higher temperatures, the impact of ALG-WPC was intense. Both free and encapsulated Hpw demonstrated concentration dependent DPPH radical scavenging activities with encapsulated Hpw showing lower antioxidant activity than free. ALG-LEC-Hpw exhibited the highest bioaccessibility among the formulations. All hydrogels retained =96% ASX at 4°C and =93% at 25°C during 28 days of storage, with highest retention observed in ALG-WPC-Hpw. These findings highlight the influence of carrier combinations in improving the properties of Hpw ASX, making it a promising system for its delivery in a broader array of food, nutraceutical, and feed applications.