Oxidative Stability and Characterization of Quinoa Oil Extracted from Wholemeal and Germ Flours

Abstract

Quinoa seeds are a source of lipids of great quality, and they highlight the content and composition of fatty acids and the presence of antioxidants such as tocopherols. Solvent extraction of quinoa oils was carried out from two matrices (wholemeal and germ flours), and in both cases, the extraction performance, physical–chemical characteristics, and oxidative stability were determined. Oxidative stability of the oil was assessed using an accelerated aging experiment under storage conditions at 60 °C for 12 days, in which the following parameters were measured: peroxide value, acid value, conjugated dienes and trienes, and scavenging radical capacity. Germ flour showed greater extraction yields (27.30 ± 0.15 g/100 g) compared to wholemeal (5.88 ± 0.02 g/100 g). Both oils presented similar physicochemical parameters, although the tocopherol content was higher in the oil extracted from germ flour (1354 vs. 735 mg/kg oil). At the same time, wholemeal oil showed a superior oxidative stability; hence, the wet milled process produces a minor impact on the compounds responsible for protection against lipid oxidation.