Effects of different extraction methods on aromatic composition of essential oils of Citrus keraji hort. ex Tanaka 'Kabuchii'.

Citrus keraji hort. ex Tanaka var. kabuchii (‘Kabuchii’) originates from Okinawa, and has been cultivated in the Okinawa Islands for hundreds of years. However, the components responsible for its characteristic fresh aroma have not been determined. ‘Kabuchii’ is used as a table fruit and also in the production of traditional sweets and juice. At present, the residues produced during the manufacturing process are underutilized. In the present study, we extracted the essential oil from ‘Kabuchii’ peel residues using different extraction methods and characterized its aromatic components by gas-chromatography/massspectrometry. We identified 70 aromatic components in the essential oil of ‘Kabuchii’, and found that different extraction methods gave oils with a similar composition. Our results suggest that the residues from citrus processing factories could be used for the manufacture of other products, e.g., aromatherapy, food, flavor, and cosmetic products. The results of present study provide data that could be used by the citrus industry to develop new ‘Kabuchii’ products.