Microencapsulation of Chia Oil Using Whey Protein and Gum Arabic for Oxidation Prevention: A Comparative Study of Spray-Drying and Freeze-Drying Methods

Encapsulation is one of the most widely utilized strategies for preventing oil oxidation. Chia oil is a source of oils that are high in omega-3s and was used as a core material in this study. Whey protein and gum arabic were used as wall materials, and the whey protein:gum arabic ratios were 1:0, 1:1, 1:2, 2:1, 1:3 and 3:1. Preparation of chia oil microcapsules was conducted by spray-drying or freeze-drying methods. All microcapsules were stored in an opaque and airtight laminate pouch for 3 and 6 months to determine the effect of time on the fatty acid composition, encapsulation efficiency and chemical properties. Encapsulation had a positive protective effect on oil quality. The two drying methods resulted in different powder characteristics: spray drying resulted in a spherical shape, whilst freeze drying led to flakes and a porous surface. Spray drying microcapsules resulted in greater encapsulation efficiency than freeze drying microcapsules. In addition, encapsulated powders stored for 6 months showed both acid and peroxide values below the Codex limit. These results indicate a possible encapsulation process to protect chia oil from oxidation.