Roasting pumpkin seeds and changes in the composition and oxidative stability of cold-pressed oils

Abstract

Background. Pumpkin seed oil is valuable oil for its distinctive taste and aroma, as well as supposed healthpromoting properties. The aim of this study was to investigate how roasting pumpkin seeds influences the physicochemical properties of cold-pressed oils. Materials and methods. The fatty acid composition, content of phytosterols, carotenoids and tocopherols, oxidative stability and colour were determined in oils after cold pressing and storage for 3 months using GC-FID, GCxGC-ToFMS, HPLC, Rancimat and spectrophotometric methods. Results. The results of this study indicate that the seed-roasting and storage process have no effect on the fatty acid composition of pumpkin seed oils, but does affect phytosterols and tocopherols. The carotenoid content decreased after storage. The colour of the roasted oil was darker and changed significantly during storage. Conclusion. Pumpkin oil obtained from roasted seeds shows better physicochemical properties and oxidative stability than oil from unroasted seeds.