CHARACTERIZATION OF CRUDE AND PURIFIED PUMPKIN SEED OIL

Oil from hulled pumpkin seeds (Cucurbita pepo and Cucurbita maxima) wa s extracted with hot petroleum ether, and then it was degummed, neutra lized and bleached, consecutively. Physical and chemical characteristi cs of crude and purified oils were determined. Density, refractive ind ex, viscosity and peroxide value were not affected by purification, wh ile decreases in acidity, colour, unsaponifiable, E-1cm(1%) 232, and o xidative stability, and increases in smoke point and E-1cm(1%) 270 wer e observed. Purification did not affect the fatty acid and sterol prof iles. GLC analysis for the fatty acid composition of the seed oil show ed that the predominant unsaturates were linoleic (42%) and oleic (38% ), while the major saturates were palmitic (12,7%) and stearic (6%). O nly a-tocopherol was detected at a level of 126 mg/kg, which reduced t o 78 mg/kg after purification. The main sterols of pumpkin seed oil un saponifiable were Delta(7,22,25), -stigmastatrien-3 beta-ol, a-spinast erol, Delta(7,25)-stigmastadienol and Delta(7)- avenasterol, followed by stigmasterol, 24-methylcholest-7-enol and Delta(7)-stigmastenol, an d also trace to minor amounts of cholesterol, brassicasterol, campeste rol, sitostanol, Delta(5)-avenasterol, erythrodiol and uvaol were foun d.