Physicochemical properties and stability of pumpkin seed oil as affected by different extraction methods and species

Abstract

The present work evaluated the influence of extraction method and species on the physicochemical properties, oxidative stability, fatty acid profiles, and rheological behaviour of pumpkin seed oils. The seeds of two pumpkin species (Cucurbita argyrosperma Huber [CA] and Cucurbita moschata Duchesne [CM]) were obtained from small-scale pumpkin processors in Yucatán, Mexico. The oils were extracted by two methods: mechanical pressing (MP) and organic solvent (OS). It was found that the oil extraction method, species, and their interaction significantly influenced the physicochemical properties and oxidative stability of the seed oils. The composition and fatty acid content of the oils were comparable to those of other pumpkin species. The oil yield from the MP method was lower than that from the OS method. Also, CA oil extracted by MP had an olive-green colour as compared to the reddish-yellow colour of CM oil, and also had a higher oxidative stability. The viscosity of CA oil extracted by MP was superior to that extracted by OS. Also, CA oil had a higher content of iron, monounsaturated fatty acids (MUFA), stearic acid, and oleic acid as well as viscosity in comparison to CM oil, although CM oil had a higher content of linoleic acid. This information can be used to obtain more stable pumpkin oils with enhanced properties that would benefit both producers and processors.