Comparative Study of Essential Oils Extracted from Egyptian Basil Leaves (Ocimum basilicum L.) Using Hydro-Distillation and Solvent-Free Microwave Extraction.

Mohammed Chenni,Njara Rakotomanomana,Xavier Fernandez,Douniazad El Abed,Farid Chemat

doi:10.3390/molecules21010113

Abstract

Solvent-free microwave extraction (SFME) and conventional hydro-distillation (HD) were used for the extraction of essential oils (EOs) from Egyptian sweet basil (Ocimum basilicum L.) leaves. The two resulting EOs were compared with regards to their chemical composition, antioxidant, and antimicrobial activities. The EO analyzed by GC and GC-MS, presented 65 compounds constituting 99.3% and 99.0% of the total oils obtained by SFME and HD, respectively. The main components of both oils were linalool (43.5% SFME; 48.4% HD), followed by methyl chavicol (13.3% SFME; 14.3% HD) and 1,8-cineole (6.8% SFME; 7.3% HD). Their antioxidant activity were studied with the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging method. The heating conditions effect was evaluated by the determination of the Total Polar Materials (TPM) content. The antimicrobial activity was investigated against five microorganisms: two Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, two Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, and one yeast, Candida albicans. Both EOs showed high antimicrobial, but weak antioxidant, activities. The results indicated that the SFME method may be a better alternative for the extraction of EO from O. basilicum since it could be considered as providing a richer source of natural antioxidants, as well as strong antimicrobial agents for food preservation.

Highlights

Aromatic plants and essential oils (EOs) have been used since ancient times and are still widely used for their biological properties [1,2] and their applications in various industries: food, cosmetics, perfumery, and pharmacy [3]
The results show a high level of Molecules 2016, 21, 113OO enriched with basil EO, especially those isolated by solvent-free microwave extraction (SFME)
The solvent-free microwave extraction (SFME) technique has been compared with the conventional hydro-distillation (HD) method, for extraction of EO from Egyptian basil (O. basilicum L.)

Summary

Introduction

Aromatic plants and EOs have been used since ancient times and are still widely used for their biological properties [1,2] and their applications in various industries: food, cosmetics, perfumery, and pharmacy [3]. The basil leaves are used in folk medicine as a remedy for a large number of diseases, native to India and other Asian regions. Today, it is cultivated all over the world [6]. Including cancer, convulsion, diarrhea, epilepsy, gout, nausea, sore throat, toothaches, and the basil leaves are used in folk medicine as a remedy for a large number of diseases, including bronchitis [7,8,9] It is a source of EO containing biologically-active constituents which possess cancer, convulsion, diarrhea, epilepsy, gout, nausea, sore throat, toothaches, and bronchitis [7,8,9]

Objectives

Methods

Conclusion