Oxidative stability of sesame and flaxseed oils and their effects on morphometric and biochemical parameters in an animal model.

Background: Sesame and flaxseed oils, which are rich in essential n-6 and n-3 polyunsaturated fatty acids, are widely consumed. We have determined the optical behavior with respect to the quality and identity of cold-pressed sesame and flaxseed oils. The effects of these oils and their combinations on metabolic parameters in animal models were also measured.

Results: Flaxseed oil emitted carotenoid fluorescence (500-650 nm), although it was more unstable than sesame oil, which had a larger induction period by the Rancimat method. The greater stability of sesame may be a result of the lower quantity of linolenic fatty acids. These oils were added to the feed of 56 rats, whereas animal fat was used for the control group. The sesame oil, flaxseed oil and sesame + flaxseed oils groups showed a significantly reduced adiposity index and blood glucose compared to the control group, whereas total cholesterol, high-density lipoprotein and triglycerides were lower in flaxseed oil and sesame + flaxseed oils (P < 0.05). Sesame + flaxseed oils had reduced levels of low-density lipoprotein and non-high-density lipoprotein (P < 0.05), indicating an anti-atherogenic effect in this group.

Conclusion: Sesame oil was more stable than flaxseed oil. In an animal model, the diets with polyunsaturated fat sources proportions of 1:1 n-6:n-3 polyunsaturated fatty acids, improved the metabolic parameters, implying cardioprotective effects. © 2016 Society of Chemical Industry.