Effect of some variables on oil extraction yield from Mexican pumpkin seeds

The effect of particle size (0.59 and 1.19 mm), meal to solvent ratio (1:5, 1:10, 1:15, and 1:20 w/v) and contact time (0, 1, 2, and 5 h) on oil extraction yield and efficiency from pumpkin (Cucurbita pepo) seeds using n-hexane were evaluated. Fatty acids profile was determined for the extracted oil. Results were analyzed by response surface methodology. Particle size, meal to solvent ratio and contact time, affected (p < 0.05) extraction yield. The yield (422 g/kg) and efficiency (860 g/kg) were highest at 0 h contact time, 0.59 mm particle size and a 1:20 (w/v) pumpkin seed meal:solvent ratio. Pumpkin seed oil contained (755 g/kg) unsaturated fatty acids and an elevated content of linoleic (431 g/kg) and oleic acids (324 g/kg). It is therefore classified as a high linoleic-oleic acids oil, making it a promising substitute for cotton, corn, sesame, sunflower, or soybean oils in our Mexican diet.