ORIGINAL PAPER Full-Press Oil Extraction of Cuphea (PSR23) Seeds Roque L. Evangelista Æ Steven C. Cermak Received: 12 January 2007 / Revised: 31 August 2007 / Accepted: 13 September 2007 / Published online: 13 October 2007 Ó AOCS 2007 Abstract Cuphea PSR23, a semi-domesticated, high- capric-acid hybrid from Cuphea viscosissima · Cuphea lanceolata, is being developed as a potential commercial alternative source of medium-chain fatty acids. The present study evaluated the effects of initial seed moisture and final moisture contents of cooked flaked seed on Cuphea’s pressing characteristics and the quality of the extracted oil. Seeds with 9 and 12% initial moisture contents (MC) were flaked and cooked at different residence times to produce cooked seeds with MC of 3.0–5.5%. Cooked seeds were pressed using a laboratory screw press. Eighty and 84% oil were extracted from cooked seeds with 5.5 and 3.0% MC, respectively. The seeds with 9% initial MC exhibited lower pressing load increase (9.1 per 1% decrease in MC) than the seeds with 12% initial MC (16.4 per 1% decrease in MC). The pressing rate decreased by 3% as the cooked flaked seed MC decreased. The amount of foots in the oil increased from 3 to 6.6% and chlorophyll content increased from 200 to 260 ppm as cooked flaked seed MC decreased from 5.5 to 3.0%. FFA contents were 2.5% for all treat- ments MC studied. The phosphatide content increased as the cooked flaked seed MC decreased but the amounts were still within the levels of water-degummed oil. Keywords Cuphea Á Oil extraction Á Screw pressing Á Crude oil quality Introduction Cuphea, of the family Lythraceae, is a large genus of over 200 species of herbs and shrubs growing in the tropics and subtropics of the Americas. Several Cuphea species con- tain saturated medium-chain fatty acids (MCFAs) [1–3]. MCFAs (C8:0–C12:0) are used in soaps, detergents, cos- metics, lubricants, and food applications. One-half of the MCFAs used by the US soap and detergent industry is obtained from coconut and palm kernel oils, while the other half is from petroleum [4]. Efforts to domesticate Cuphea have progressed over the past three decades. Seed shattering and seed dormancy have been the main hurdles to successful commercializa- tion [5, 6]. A semi-domesticated, high-capric-acid variety with partial seed retention (PSR) was reported by Knapp in 1993 [7]. Cuphea PSR23 is a hybrid between Cuphea viscosissima (a species native to the United States) and Cuphea lanceolata (a species native to Mexico). The seeds weigh 538 g/l (3.3 g/1,000 seeds) and contain up to 35% oil. The oil typically contains around 70% capric, 9% oleic, 6% palmitic, 5% linoleic, 4% myristic, and 3% lauric acids [8]. Cuphea PSR23 has been the subject of field studies for the past 6 years in west central Minnesota and central Illinois to establish the best agronomic management prac- tices in preparation for commercial production [9–13]. Recent seed increases in Cuphea provided sufficient amounts of seed to conduct oil extraction studies, and at the same time, produce much needed oil for product devel- opment and applications testing. The first report on oil extraction from Cuphea seeds was for prepressing cooked This paper may contain brand names that are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable. R. L. Evangelista (&) Á S. C. Cermak New Crops and Processing Technology Research Unit, NCAUR, ARS, USDA, 1815 N University St, Peoria, IL 61604, USA e-mail: Roque.Evangelista@ars.usda.gov 123 J Am Oil Chem Soc (2007) 84:1169–1175 DOI 10.1007/s11746-007-1142-5