Cucurbita maxima pumpkin seed oil: From the chemical properties to the different extracting techniques

Abstract

Pumpkin seed oils are rich in bioactive compounds such as tocopherols, sterols, ß-carotene, and lutein that have, along with some fatty acids, high nutritional value factors. In addition, it has so far been proven that these compounds have a positive effect on human health. The present study mainly aimed at evaluating the chemical composition and the bioactive compounds of pumpkin (Cucurbita maxima) seed oil of the 'Béjaoui' Tunisian cultivar using both cold pressing and solvent extraction methods. The seed oils contained substantial amounts of unsaturated fatty acids, particularly oleic and linoleic acids, with values ranging respectively from 28.19% for cold pressed pumpkin seed oil to 30.56% for pumpkin seed oil extracted by pentane and from 43.86% for pumpkin seed oil extracted by pentane to 46.67% for cold pressed pumpkin seed oil of the total amount of fatty acids. Investigations of different seed oils revealed that extraction techniques had significant effects on the antioxidant activity and the γ-tocopherol. Cold pressed pumpkin seed oil revealed the highest γ-tocopherol content (599.33 mg kg-1) and the highest oxidative stability (3.84 h). However, the chloroform/methanol extracted pumpkin seed oil, which is rich in total phenolics (54.41 mg Gallic Acid Equivalent kg-1), was a more effective scavenger of DPPH radicals (250 μmoles Trolox kg-1) than the poor phenolic pumpkin seed oils extracted by hexane and pentane (110 μmoles Trolox kg-1wws vs 100 μmoles Trolox kg-1). Based on its unique seed oil features, cold press extracted pumpkin seed may add great value to product innovation in the industrial, nutritional, cosmetic, and pharmaceutical fields.