Effect of Rosmarinus officinalis, Lavandula sublepidota, and Ferulago contracta Essential Oils on Oxidative Stability of Camelina Oil

Rosmarinus officinalis​ L. (RO), Lavandula sublepidota (LS), and Ferulago contracta (FC) are three botanical species recognized for their antioxidant, antibacterial, and anticancer properties, which make them significant for improving food quality and prolonging shelf life. In this study, the oxidative stability of Camelina sativa seed oil (CSO) enriched with RO, LS, and FC essential oils (EOs) at 100, 300, and 500 ppm was assessed and compared to tert-butyl hydroquinone (TBHQ) at 75 and 150 ppm. The evaluation of total phenol content (TPC), DPPH radical scavenging activity, acidity value (AV), peroxide value (PV), p-anisidine value (pAV), oxidative stability via Rancimat, and Fourier transform infrared spectroscopy (FTIR) of the samples was conducted at intervals of 0, 30, 60, and 90 days. The largest TPC (17.81 ± 0.05 (μgGAE/mL)) and antioxidant capacity were achieved for FC-500 (73.67% ± 0.37%) and LS-500 (78.16% ± 0.11%) on Day 90, respectively, which were higher than the values determined for TBHQ-75 (73.39% ± 0.23%). FC-500 and LS-500 indicated lower acidity, peroxide, and pAV, while TBHQ-75 and TBHQ-150 showed the lowest values. The highest induction period (1.07 and 1.04 h) was obtained for LS-500 and FC-500 on Day 90, which was close to TBHQ 150 and 75 ppm on Day 90 (1.58 and 1.12 h), respectively. FTIR spectroscopy indicated that the addition of EOs at 300 and 500 ppm led to higher oxidative stability and lower alterations at 1400 to 1000 cm⁻¹. All samples that included either synthetic or natural antioxidants exhibited a linolenic acid plus eicosenoic acid content exceeding 49.4%. In conclusion, the EOs derived from RO, LS, and FC have the potential to enhance the oxidative stability of CSO.