Antioxidant and antibacterial activities of omega-3 rich oils/curcumin nanoemulsions loaded in chitosan and alginate-based microbeads.

Omega-3 fatty acids can be considered as potential alternative therapeutic agents because of their antimicrobial and antioxidant properties. Two investigated omega-3 rich oils (flaxseed or fish) have been nanoemulsified with and without the natural antioxidant (curcumin, Cur) followed by their incorporation into crosslinked polymeric microbeads. The microbeads were developed from chitosan (CS), alginate (AL) and their combination (CSAL). Results indicated that the mean droplet diameter of the plain and Cur-loaded nanoemulsions ranged from 62.3 to 111.29 nm. The microbeads produced from AL, CS and their combination without Cur had predominantly shriveled surfaces compared to Cur-loaded ones. Addition of Cur was found to enhance oxidative stability, encapsulation efficiency, loading capacity, and antioxidant activity of the formulated microbeads. Plain fish oil revealed more antibacterial activity than plain flaxseed oil. Fish oil nanoemulsion-in-AL microbeads had more antibacterial activity than nanoemulsions of flaxseed oil-in-AL, fish oil-in-CS and the combined (CSAL) microbeads. However, flaxseed oil nanoemulsion-in-CS microbeads showed higher antibacterial activity than nanoemulsions of fish oil-in-CS, flaxseed oil-in-AL and the combined microbeads. The obtained results suggested the suitability of the formulated nanoemulsions-loaded microbeads to be used in food and pharmaceuticals products.