Introduction
Essential oils (EOs) are aromatic volatile liquids obtained from plant materials whether they are vascular plant or nonvascular plants including; buds, flowers, fruits, seeds, leaves, twigs, bark, wood ,roots and herbs. Citrus plants constitute one of the main essential oils sources (Burt, 2004; Hammer, 1999). They belong to Rutaceae family, which originated from tropical and subtropical south-eastern parts of the world (Sawamura, 2010). Citrus species were cultivated in China long time ago, an ancient manuscript from 1178 Han Yen-Chih described 27 varieties of sweet and bitter oranges and mandarins with all relevant agricultural practices (Bonaccorsi and Dugo 2014). Citron was the first citrus to be known in Europe. Theophrastus …show more content…
This increase is also followed by great growth in processed citrus products. Spreen (2001) projected that the world production and consumption of citrus in 2010 will reach more than 64 million metric tonnes. In the FAO statistical yearbook of 2013 (FAO, 2013) the citrus production nearly reached 123 million metric tonnes (122 976 thousand tons) in year 2010 which is nearly double the Spreen (2001) projection. This vast current and projected increase in citrus production and processing will pave the way for high rate of peel production, which is the main source of essential oils.
The major classical use of citrus essential oils (CEOs) from citrus peel is as natural flavouring materials, which have great commercial importance. Worldwide demand for essential oils, especially citrus oils is increasing as recognized by Choi and Sawamura, (2000). Peel produce more essential oil than leaves, Vekiari et al (2002) have demonstrated this clearly in some lemon varieties.
Adams et al (2003) mentioned that approximately 36 million kg of limonene are recovered as a by-product of the citrus industry annually.
Extraction of …show more content…
(2007) and Bousbia et al. (2009) described a new and relatively simple microwave hydro-diffusion and gravity (MHG) method of extraction of CEOs, which can be used in laboratory and or industrial scales. In this method, the plant material is directly placed in a microwave reactor without any added solvent or water. The internal heating of the in situ water within the plant material distends the plant cells and leads to rupture of the glands and cell receptacles so that the heating frees molecules of interest together with in situ water. The extract diffuse outside the plant material and drop by earth gravity out of the microwave reactor through the perforated Pyrex disc, a heat exchanger outside the microwave oven cools the extract continuously.
Lago et al (2014) described using of acetate ionic liquids as solvents in liquid-liquid extraction of essential oils from citrus peel. They stated that the quality of produced essential oil increase due to due to better recovery of oxyterpenes and other derived oxygenated compounds as terpenes are removed from the extract because it may lead to instability or loss of quality of the essential oil.
Boukroufa et al (2015) developed a method of bio-refinery for orange peel waste using combination of microwave and ultrasound while water of peels is recycled leading to the attainment of high benefits compounds in a short
Essential oils (EOs) are aromatic volatile liquids obtained from plant materials whether they are vascular plant or nonvascular plants including; buds, flowers, fruits, seeds, leaves, twigs, bark, wood ,roots and herbs. Citrus plants constitute one of the main essential oils sources (Burt, 2004; Hammer, 1999). They belong to Rutaceae family, which originated from tropical and subtropical south-eastern parts of the world (Sawamura, 2010). Citrus species were cultivated in China long time ago, an ancient manuscript from 1178 Han Yen-Chih described 27 varieties of sweet and bitter oranges and mandarins with all relevant agricultural practices (Bonaccorsi and Dugo 2014). Citron was the first citrus to be known in Europe. Theophrastus …show more content…
This increase is also followed by great growth in processed citrus products. Spreen (2001) projected that the world production and consumption of citrus in 2010 will reach more than 64 million metric tonnes. In the FAO statistical yearbook of 2013 (FAO, 2013) the citrus production nearly reached 123 million metric tonnes (122 976 thousand tons) in year 2010 which is nearly double the Spreen (2001) projection. This vast current and projected increase in citrus production and processing will pave the way for high rate of peel production, which is the main source of essential oils.
The major classical use of citrus essential oils (CEOs) from citrus peel is as natural flavouring materials, which have great commercial importance. Worldwide demand for essential oils, especially citrus oils is increasing as recognized by Choi and Sawamura, (2000). Peel produce more essential oil than leaves, Vekiari et al (2002) have demonstrated this clearly in some lemon varieties.
Adams et al (2003) mentioned that approximately 36 million kg of limonene are recovered as a by-product of the citrus industry annually.
Extraction of …show more content…
(2007) and Bousbia et al. (2009) described a new and relatively simple microwave hydro-diffusion and gravity (MHG) method of extraction of CEOs, which can be used in laboratory and or industrial scales. In this method, the plant material is directly placed in a microwave reactor without any added solvent or water. The internal heating of the in situ water within the plant material distends the plant cells and leads to rupture of the glands and cell receptacles so that the heating frees molecules of interest together with in situ water. The extract diffuse outside the plant material and drop by earth gravity out of the microwave reactor through the perforated Pyrex disc, a heat exchanger outside the microwave oven cools the extract continuously.
Lago et al (2014) described using of acetate ionic liquids as solvents in liquid-liquid extraction of essential oils from citrus peel. They stated that the quality of produced essential oil increase due to due to better recovery of oxyterpenes and other derived oxygenated compounds as terpenes are removed from the extract because it may lead to instability or loss of quality of the essential oil.
Boukroufa et al (2015) developed a method of bio-refinery for orange peel waste using combination of microwave and ultrasound while water of peels is recycled leading to the attainment of high benefits compounds in a short