Effect of biologically active substances on oxidative stability of flaxseed oil

The enrichment of flaxseed oil, which is a valuable plant source of PUFA omega-3, fat-soluble vitamins and other biologically active substances (BAS), makes it possible to strengthen the therapeutic and prophylactic effect of flaxseed oil. The study of the effect of BAS additives on the oxidative stability of flaxseed oil is an important step in the process of creating products based on enriched flaxseed oil. Experiments were conducted to investigate the influence of added BAS (coenzyme Q₁₀, β-carotene, lutein, zeaxanthin, α-tocopherol, α-tocopherol acetate, cholecalciferol, selenomethionine) on flaxseed oil oxidation stability. Kinetic data on accumulation of primary and secondary oxidation products, free fatty acids in flaxseed oil, as well as the consumption of BAS added to the oil during its storage, were obtained. Experimental results showed that the BAS could have both antioxidant and pro-oxidant properties depending on their chemical structure and concentration. Coenzyme Q₁₀, carotenoids and selenomethionine at concentrations higher than 100, 10 and 0.5 mg/100 g respectively, accelerate significantly (p < 0.05) the oxidation of flaxseed oil. An addition of 5 mg/100 g β-carotene inhibits formation of flaxseed oil oxidation products. The co-influence of synthetic and natural oxidation inhibitors with BAS on oxidative stability of flaxseed oil was studied. The fat-soluble esters of ascorbic acid and their compositions with natural antioxidants based on beans and soybeans appeared to be effective and safe stabilizers of flaxseed oil enriched with BAS. Resulting from the studies, new oxidation-resistant functional food products based on flaxseed oil are launched into manufacturing.