Abstract

EXTRACTION OF ESSENTIAL OIL FROM CITRUS LIMON AND CITRUS LIMETTA: CHARACTERISATION AND ANTIOXIDANT ACTIVITY

M. Asinruth, R. Renuka, R. Ragunathan and Jesteena Johney*

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Abstract

Citrus peels contain various bioactive compounds which show therapeutic value. Soxhlet extraction with ethanol as the solvent was used to extract essential oils from Citrus limon (lemon) and Citrus limetta (mosambi) peel samples. Phytochemical analysis showed alkaloids terpenoids and flavonoids steroids and sugars occurred in both citrus samples but quinine was found specifically in mosambi and phenol-only products and proteins existed only in lemon. The analysis by thin-layer chromatography (TLC) showed different compound separations for Citrus limon which had three compounds with Rf values at 0.246, 0.692, 0.815 and Citrus limetta contained two compounds with Rf values of 0.307, 0.415. The antioxidant measurements revealed mosambi (276 μg/g) exhibited higher activity than lemon (218 μg/g). Total phenolic content reached 0.814 μg/g in mosambi whereas lemon showed 0.740 μg/g but FRAP results demonstrated stronger reducing power in lemon with 0.692 μg/g compared to mosambi with 0.421 μg/g. The extracted oils received microencapsulation treatment through the sodium alginate method for developing more stable products with planned market applications. Studies revealed distinct phytochemical patterns and antioxidant capabilities between Citrus lemon and Citrus limetta which demonstrates their practical applications in pharmaceutical development and nutraceutical usage.

Keywords: Citrus peel oil, Phytochemical analysis, Antioxidant activity, Thin-layer chromatography, Microencapsulation.