Expeller Pressing of Pumpkin Seed Oil: Oil Yield, Quality, Fatty Acid Profile, and Bioactive Compounds

ABSTRACT The seeds constitute approximately 3.34% (w/w) of pumpkin ( Cucurbita moschata ), a byproduct rich in bioactive compounds. Cucurbita seeds may contain approximately 33% oil with a unique composition and nutritional value. The present study aimed to obtain pumpkin ( C. moschata ) seed oil by screw pressing (expeller) from four superior lines obtained through self‐fertilization cycles, as well as a hybrid resulting from the crossing of two lines developed at the Embrapa Semi‐arid plant breeding program. A commercial sample was used as a control. The oil was extracted using an expeller press with a maximum capacity of 3–5 kg/h, and the oil yield, oil recovery, and cake residual oil content were evaluated. The oil quality, fatty acid profile, tocochromanol, and carotenoid composition were assessed. There was a significant difference in seed oil content (27%–37%, dry weight), oil yield after pressing (13.6%–26.2%) and cake residual oil content (14.1%–18%) ( p < 0.05) that presented a positive and negative correlation with the seed oil content, respectively. Peroxides and free fatty acid content were up to 2.28 meq/kg and 0.22%, respectively, showing the high initial quality of screw pressed oils. There were significant differences ( p < 0.05) for the fatty acid profile, and the main fatty acids were C18:2 (35.6%–38.9%), C18:1 (32.2%–37.5%), C16:0 (13.5%–15.3%), and C18:0 (9.4%–11.4%). The screw‐pressed pumpkin seed oil presented high amounts of gamma ‐tocopherol (442–686 mg/kg). The results showed the feasibility of the process in obtaining an oil rich in bioactive compounds.