Yield and Composition of Oil from Japanese Cornmint Fresh and Dry Material Harvested Successively

Japanese cornmint (Mentha canadensis L., synonym M. arvensis L.) is a subtropical plant with major producers India, China, Vietnam, and Brazil (Chand et al., 2004; Clark, 1998; Kumar et al., 2000; Lawrence, 2007; Singh and Saini, 2008). Th ere is no production of Japanese cornmint in the United States despite some incorrect reports (Pandey et al., 2003; Singh and Saini, 2008). Japanese cornmint is the only commercially viable source of crystalline menthol, which is used in pharmaceutical, food, fl avor, and fragrance industries (Clark, 1998; Chand et al., 2004; Galeotti et al., 2002; Lawrence, 2007; MIRC, 2010; Shrivastava et al., 2002; Topalov, 1962; Topalov, 1989). Th e United States is a major importer of Japanese cornmint essential oil and (-)-menthol (the MIRC, personal communication, 2007). Due to inconsistencies with supply and quality of (-)-menthol or Japanese cornmint essential oil, mint growers and broker companies are interested in domestic U.S. production of Japanese cornmint. Japanese cornmint can be a viable crop in the southeastern United States and provide desirable oil composition with a high concentration of (-)-menthol (Zheljazkov et al., 2010a). A limiting factor for the establishment of Japanese cornmint production in the southern and southeastern United States has been the lack of suffi cient information on agronomics and postharvest management of this potential new crop. Harvesting time is important because of its direct eff ect on number of cuts in a cropping season. Another important aspect that has not been addressed in the United States is drying of Japanese cornmint before essential oil extraction. To increase effi ciency of essential oil extraction, peppermint and spearmint producers in the Midwest and northwestern United States traditionally have been drying the harvested biomass, which results in lower transportation and extraction costs. Th e objective of this study was to assess changes in essential oil content and composition of Japanese cornmint as a function of harvesting time and drying.