Effect of liposomal encapsulation of curcumin and α-tocopherol on sensory and physicochemical properties, and retention of antioxidant capacity of fortified cookies during baking

Abstract

Curcumin and α-tocopherol, which are potent antioxidants usable for food fortification, are sensitive to heat and air, thus showing the need for protection. The aim of this study was to increase the antioxidant capacity retention of curcumin and α-tocopherol in fortified cookies via liposomal encapsulation. Liposomes were prepared using the homogenization method and the liposomes were multilamellar according to light microscopic images. Liposomal encapsulation exhibited encapsulation efficiencies greater than 90 %. The sensory tests, conducted using a 5-point hedonic scale for nine attributes, revealed that the incorporation of liposomal antioxidants did not compromise the sensory attributes of the cookies. The color of liposomal-curcumin incorporated cookie deviated greater than that of free-curcumin incorporated cookie from the regular cookie. Nevertheless, the color of the α-tocopherol incorporated cookies improved on using the liposomal compound as opposed to the free compound. The antioxidant capacity of the cookies, along with the controls, was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. As expected, liposomal encapsulation of curcumin or α-tocopherol mitigated the reduction of antioxidant capacity of fortified cookies during baking. Briefly, liposomal encapsulation proves to be a potent method for retaining the antioxidant capacity of curcumin or α-tocopherol in cookies during baking.