Tailoring oxidative, thermal and tribological properties of Camelina oils through fatty acid engineering

The development of vegetable oils with customized physicochemical properties is increasingly important for food, oleochemical and biobased industrial applications. Camelina sativa has emerged as a promising platform for oil tailoring due to its favorable agronomic characteristics, rapid life cycle and high transformation efficiency. In this study, a collection of genetically engineered camelina lines displaying contrasting fatty acid compositions was generated through the modulation of key desaturation and elongation steps in lipid metabolism, including RNAi-mediated suppression of FAD2 and FAE1 in both wild-type and ω-7-enriched genetic backgrounds. The resulting oils exhibited substantial variation in fatty acid and triacylglycerol (TAG) composition, enabling the assessment of how specific lipid architectures influence functional oil properties. Oils enriched in monounsaturated fatty acids (MUFAs), particularly oleic and palmitoleic acids, showed markedly improved oxidative stability compared with polyunsaturated counterparts. Differential scanning calorimetry revealed that fatty acid composition strongly affected phase-transition behavior, with MUFA-rich oils displaying simpler melting profiles, higher crystallization temperatures and more ordered thermal transitions, whereas PUFA-rich oils exhibited broader melting intervals and lower melting enthalpies. Changes in fatty acid composition also influenced rheological and tribological performance. Oils enriched in oleic acid and very-long-chain fatty acids (VLCFAs) displayed increased dynamic viscosity and improved friction and wear behavior. In contrast, oils enriched in palmitoleic and asclepic acids exhibited enhanced load-carrying capacity under pure sliding conditions. Comparisons with conventional and high-oleic sunflower oils further demonstrated that both the degree of unsaturation and acyl-chain length are major determinants of oxidative resistance, thermal behavior and lubrication performance. Overall, the results demonstrate that targeted fatty acid engineering in Camelina sativa provides an effective strategy for developing seed oils with tailored physicochemical and tribological properties, expanding the potential of this crop as a sustainable source of high-value industrial feedstocks.