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

Key Findings

The characteristics of an oil is important to avoid damage to the body, the intake of oxidized fatty acids derived from seed oils can, however, causes a range of metabolic complications due to intestinal absorption and incorporation of these oxidized acids in lipoproteins. This study characterized cold-pressed flaxseed and sesame oils according to their optical behavior and their quality and identity, their fatty acid profiles, and their effects on plasma lipids and morphometric parameters in Wistar rats. The groups that consumed flaxseed oil in the diet, FO and SFO showed improvements in biochemical parameters of total cholesterol, VLDL and triglycerides. These cardioprotective effects observed in the FO and SFO groups result from a series of anti-inflammatory mechanisms of n-3 PUFAs, such as inhibition in inflammatory signaling pathways (nuclear factor-κ B activity) and down regulation of fatty acid synthesis gene expression (sterol regulatory element binding protein-1c). The sesame oil proved more stability than flaxseed oil. The diets containing flaxseed oil and/or sesame oil improved morphometric and biochemical parameters. It indicates supplementation of current Western diets with reasonable proportions of 1:1 n-6 and n-3 PUFAs is beneficial.

ABSTRACT

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 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), but it was more unstable than sesame oil, which had a larger induction period by the Rancimat method. The greater stability of sesame may be due to the lower quantity of linolenic fatty acids. These oils were added to the feed of 56 rats, while animal fat was used for the control group (CG). The SO (sesame oil), FO (flaxseed oil) and SFO (sesame + flaxseed oils) groups showed a significantly reduced adiposity index and blood glucose compared to CG, while total cholesterol, HDL and triglycerides were lower in FO and SFO (P<0.05). SFO had reduced levels of LDL and non-HDL (P<0.05), indicating an anti-atherogenic effect in this group. CONCLUSION:  Sesame oil was more stable than flaxseed oil. In 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.