Comparative Study of Thermal Pre-treatment on the Extraction, Antioxidant, Fatty Acid Profile, and Physicochemical Properties of Inca Inchi Seed Oil

Abstract

Inca Inchi oil, an edible oil with high amounts of polyunsaturated fatty acids such as omega 3 and omega 6 fatty acids, has a wide range of applications in therapeutic, food, and pharmaceutical industries. Increasing its oil yield during oil extraction is important due to its high value. However, conventional techniques such as screw press extraction pose a limitation in terms of oil yield. Thus, in this study, the seeds were pre-treated in a microwave and hot air oven prior to oil extraction. The effects of this pre-treatment on the oil yield, fatty acid profile, antioxidant profile, and physicochemical properties were compared. Microwave treatment (4 min) was found to have the highest oil yield (43.39%) compared to control (37.76%). The proximate analysis revealed that the protein content in the oil meal was high (51–60%) compared to oil seed (24.2%), indicating that it has potential application to be developed into plant-based protein foods. The fatty acid profile indicates that the oil had high omega 3 (49%) and omega 6 (37%) fatty acids. The free fatty acids and peroxide values of the pre-treated oil samples were less than 1% and 10 meq O2/kg oil, respectively, compared to the control (1%), while the iodine value was high due to double bonds. The 2,2-diphenyl-1-1picrylhydrazyl and 2,2´-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid study shows that the oil has good radical scavenging activity (70 and 90%), which shows the oil’s potential in functional food applications.