Fatty acids profile and stability of Camelina (Camelina sativa) seed oil as affected by extraction method and thermal oxidation

Abstract

Camelina (Camelina sativa) seed oil was extracted using two different methods including hexane extraction to obtain hexane-extracted oil (HEO) and cold pressing extraction to obtain cold-pressed oil (CPO). The major fatty acid was linolenic acid (C18:3) that accounted for 34.5% and 33.9%, in CPO and HEO, respectively. Both extracted camelina oils showed high amounts of linoleic acid (C18:2), eicosanoic acid (C20:1) and oleic acid (C18:1). The oxidative stability was compared for both camelina oils as affected by thermal oxidation. High and moderate temperature experiments were used to determine the resistance of both oils to accelerated oxidation. Rancimat test was applied at 110 degrees C, wherein the oxidation stability index (OSI) value for HEO (7.23 h) was higher than CPO (3.37 h). The increase rates in peroxide value (PV) and conjugated diene (CD) of HEO were higher than CPO during storage at moderate temperature (60 degrees C). The initial PV of CPO and HEO was 3.57 and 4.32 meq O-2/kg, but after 10 days of storage at 60 degrees C PV reached up to 107.30 and 11.26 meq O-2/kg, respectively. At the end of storage, CD values of CPO and HEO increased from 1.46, 1.73 to 10.08, 2.62, respectively. The volatile oxidation compounds including hexanal, 2,4-heptadienal, and (E,E)-2,4-heptadienal were identified in the head space of CPO at the 10th day of storage at 60 degrees C. It could be concluded that the extraction methods influenced significantly Camelina sativa seed oil oil stability and quality.