Physico-chemical and antioxidant properties of oils and by-products obtained by cold press-extraction of Tunisian Opuntia spp. seeds

Abstract

Screw pressed prickly pear seed cakes from four Tunisian varieties were analyzed for their chemical and some functional and antioxidant properties, along with the physico-chemical characteristics of the extracted oils. This extraction yielded 40.14 to 62.95% of oil. Fatty acid (FA) composition revealed domination of linoleic and oleic acids and high content of polyunsaturated FA (∼69-74 %) with presence of ɣ-linolenic, docosadienoic and eicosapentanoic acids. Characterization of the cake seeds showed high amounts of total dietary fibers (82.41-83.54 %), important polyphenol content (∼113-180.81 mg GAE/100g dry matter (DM)) and scavenging activity (IC50: 450-763 μg/mL), good oil holding capacity (4.31g/g for Opuntia Stricta variety), and light beige colors. Amino-acid composition revealed that major components were Glutamic acid, Arginine and Aspartic acid. The data indicate that cold pressed Opuntia seeds could be a source of fiber concentrates which could be used as functional ingredients in the food industry, as well as good quality oils.

Keywords

• Screw press
• Opuntia seeds
• Press cake
• Oil
• Fatty acids
• Antioxidant properties