Shelf Life of Cold-Pressed Pumpkin (Cucurbita pepo L.) Seed Oil Obtained with a Screw Press

摘要

The production of cold-pressed oil from nonroasted naked pumpkin seeds by pressing with screw presses started in the Republic of Serbia at the end of 1990s. This oil has the characteristic flavour of raw-dried seeds, and is a specific product of this region. The oil samples were prepared by pressing naked pumpkin seeds and pumpkin seeds with the hulls in a 3:2 ratio using a screw press. The changes of the oil sensory characteristics, basic chemical quality and oxidative stability were followed over a 2-year period. The results obtained showed that the oil sensory quality was stable during the first 12 months of storage, after which the flavour became musty. Although the chemical quality of the oil deteriorated to some extent, both the acid and peroxide values satisfied the legislative minimum during the whole investigation time. The oxidative stability of oil determined by a Rancimat apparatus was good, although the induction period after 2 years decreased by 25–40%. To ensure the use of only the highest quality oil, a 12-month shelf life is recommended.