Essential Oil Extraction from Various Natural Sources: A Comprehensive Review of Methods, Phytochemistry, and Biological Activities

Abstract

Essential oil is volatile organic liquid compound extracted from different plant parts of various plant materials. Essential oil has been used in many industries like pharmaceuticals, perfumery, cosmetics, and food industries due to their natural properties like antifungal, anti-aging, antiseptic and many other activities. This work presents the impact of yield by conventional and non-conventional techniques including solvent extraction, soxlet extraction, hydrodistillation, steam distillation, microwave assisted extraction, ultrasound assisted extraction, microwave assisted hydrodistillation, ultrasound assisted hydrodistillation and supercritical fluid extraction on clove, lemon peels, orange peels, tulsi and nagod plants. The essential oils obtained are comprehensively characterized using analytical techniques including high-performance liquid chromatography, gas chromatography–mass spectrometry. This study it was observed that, for various plant material the traditional methods was able to achieve an extraction yield higher than the conventional method for the same amount of same amount of sample. Thus, the same yield of essential oils is obtained in less time by non-conventional techniques while conventional techniques take much longer time. The yield of essential oil also depends on the type of solvent used and the geographic origin of the plant materials. The paper presents the list out the various methods of extraction of essential oil from the different plant parts and their merits and demerits. The results obtained provide a fundamental basis for scaling up the extraction processes to an industrial level.