Assessment of oil extraction method and partial characterization of isolated oil from pumpkin (Cucurbita máxima Lam) seeds

Abstract

The seeds of auyama are oleaginous by-products of this vegetable. Its oil has physicochemical properties similar to those of oils traditionally used in the food industry and that provide benefits to the health of those who consume them. The methods of extracting oil from seeds of physical auyama (extrusion) and solvent extraction were evaluated; the extraction yield was determined. The auyama seeds were washed dried and threshed to obtain the oil-rich endosperm. For the chemical extraction an experiment was designed where the factors of variation were the time of oil extraction (150 and 180 min) and the type of solvent used (ethanol or petroleum ether). The oil obtained by the method with the highest yield was characterized physicochemically (density, pour point, humidity, fatty acid profile, acidity, peroxide index and iodine value). The yield of oil extraction by solvents was between 22 and 28 % while the mechanical extraction had a yield of 16.1 ± 0.01 %. The oil of seeds of auyama presented a density of 0.91 g/mL, pour point at 3.81 °C, and a moisture content of 3 %. The values of acidity, iodine index and peroxide index were 1.04, 78.04 and 12.7, respectively. The fatty acid profile showed that the oil of seeds of auyama presents higher content of oleic and linoleic acid (22.19 ± 0.1 % and 46.92 ± 0.7 %, respectively), which are unsaturated fatty acids. Finally, the obtained results show that the oil of seeds of auyama can be used potentially for the production of foods, as a source of unsaturated fatty acids and as a functional ingredient to take advantage of the benefits that bring this type of fatty acids to the health of the person consume.