Chemical Encapsulation and Antioxidant Activity of Citrus medica and Citrus aurantium Essential Oils

Abstract

     Among antioxidant agents, essential oils, such as Citrus essential oils, are effective antioxidants. The study aimed to determine the active compounds in citron (Citrus medica) and bitter orange (Citrus aurantium) using GC-MS, separately. Each oil would be encapsulated using natural polymers such as gelatine, chitosan, and polyvinyl alcohol to enhance their antioxidant levels. The resulting polymers were analyzedby FT-IR. Then, the antioxidant levels of all treatments were determined using the DPPH method. The results showed that citron oil contains a spectrum of active compounds distributed in the form of 26 peaks in the analysis report, the highest percentage is 85.39% for D- Limonene while the lowest is for E,E- Alpha-Farnesene and 2-Methyl-3-Indazolone-N-D1 compounds equal to 0.02%, in the other hand, the bitter orange essential oil contains a spectrum of active compounds distributed in the form of 15 peaks in the analysis report, the highest percentage is 97.08% for d- limonene while the lowest is for Trans-Ocimene compound equal to 0.03%.Results of antioxidant activity using the DPPH method and comparing with vitamin C as a control showed that the Radical Scavenging Activity (RSA) percentage of bitter orange essential oil was higher than that of citron. Also, the new polymers had a higher RSA percentagethan the original oils.