Evaluation of the quality and composition of lemon (Citrus limon) peel essential oil from an Algerian fruit juice industry

Abstract

Lemon peel essential oil is used in food, medicines, cosmetics and perfumes, detergents, aromatherapy, pathogen inhibition, and insect control. The present work aimed to investigate the physicochemical characteristics and composition of the essential oil extracted from lemon grown in Algeria. The essential oil was obtained by cold-pressing from lemon peels which lemon barks are waste from an Algerian fruit juice industry. The physicochemical properties of the essential oil were determined. Essential oil was also characterised by FTIR-ATR and by GC-MS. The obtained physicochemical properties results revealed that lemon peel essential oil was a pale yellow aromatic liquid which was miscible in ethanol. It had an approximate pH of 6, a specific gravity of 0.894, a refractive index of 1.475 and an acidic value of 2.10 mg KOH/g. The FTIR spectrum revealed the presence of alkanes, alkenes, aromatic compounds and alcohols. A total of thirty-nine chemical compounds were identified based on GC-MS analysis of the lemon peel essential oil with a variation of percentage. These compounds are dividing in three different chemical classes (monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes and others). The results showed that the monoterpene hydrocarbons are the most abundant ones in the cold pressed lemon peel essential oil which represent about 93% of the total essential oil. The major constituent was α-limonene (~ 65%) and the main aldehydes were geranial (~ 2%) and neral (~ 1%).