Antioxidant activity from limonene encapsulated by chitosan

Limonene has been reported to have the effect of inhibiting free radicals. The use of limonene is still limited because of its low solubility in water. Hence, limonene modification is needed. The solution offered to solve the problem is by encapsulating it within chitosan-NaTPP to protect from degradation and increase the solubility of chitosan in water, so that limonene coated in chitosan can increase the value of free radical inhibition activity. This study aims to obtain limonene isolation from orange peel, chitosan synthesis, chitosan modification, limonene-chitosan encapsulation, and followed by antioxidant test. The results show that limonene can be isolated from orange peel. Emulsion prepared by spontaneous emulsification method obtains limonene emulsion with particle size of 339.5 nm. Chitosan modification using NaTPP obtained micro particle size of 2249.7 nm. Encapsulation of limonene in chitosan particles carried out using freeze drying method obtain an encapsulation efficiency of 46%. Limonene-chitosan encapsulation has antioxidant activity with IC₅₀ value of 116 ppm.