The aim of this work was to identify effective and safe antioxidants (AO) for stabilization of flaxseed oil and extension of its shelf life. A number of AO (both synthetic and natural ones) as well as their compositions are currently used for inhibiting oxidation processes. Their efficacy in flaxseed oil under conditions of accelerated oxidation at 100°С was tested. The fat‐soluble ascorbic acid esters displayed significant antioxidant activity. The stabilizing effect of ascorbyl palmitate (AP) was more apparent in the oil samples with higher alpha‐linolenic acid (ALA) content and lower oxidation resistance. AP alone ensured better stabilization efficacy than some known AP‐based compositions. Kinetic data were obtained characterizing accumulation of primary and secondary oxidation products in flaxseed oil added with AP during the storage at room temperature and with free access of the air. The calculated values of stabilization factor (3.7 and >6 at AP concentrations of 0.01 and 0.02%, respectively) demonstrated high inhibiting activity of AP under these conditions. It has also been found that haricot and soy beans, as well as compositions thereof, at an oil concentration of 0.8% effectively inhibit the oxidation and oxidative destruction of flaxseed oil lipids. Both AP and vegetable compositions based on legume seeds could be recommended for effective stabilization of flaxseed oil and substantial prolongation of its shelf life. Practical application: High antioxidant activity in flaxseed oil of fat‐soluble esters of ascorbic acid, as well as vegetable stabilizers based on haricot and soy beans, enables significant increase of the shelf life of the oil. The use of AP alone and legume based stabilizers ensure reliable and safe protection of flaxseed oil from oxidation, and these both methods are applicable to industrial production of edible flaxseed oil and the products on its basis. The corresponding technological methods of practical application of AP and vegetable legume‐based stabilizers in industrial production of oxidation‐resistant edible flaxseed oil have already been developed and introduced into oil production process by the authors of this article. Additive stabilizers based on bean and soybeans effectively inhibit the oxidation and oxidative destruction of flaxseed oil lipids. High antioxidant activity in flaxseed oil of vegetable stabilizers enables significant increase of the shelf life of the oil. The use of legume based stabilizers ensure reliable and safe protection of flaxseed oil from oxidation, and this method is applicable to industrial production of edible flaxseed oil and the products on its basis.

Effects of a number of quinones and diphenols of various structures on free-radical fragmentation processes taking place in alpha-diols, glycerol, 2-aminoethanol, glycero-1-phosphate, ethylene glycol monobutyrate, maltose, and some lipids were investigated. Quinone additions have been found to change the direction of free-radical transformations of the compounds cited above by inhibiting formation of the respective fragmentation products owing to oxidation of radicals of the starting compounds. The results obtained and literature data available allow a suggestion to be made that the system quinone/diphenol is able to not only deactivate or generate such active species as O2.- but also control the realization probability of free-radical processes of peroxidation and fragmentation in biologically important molecules.

The most effective processes leading to the C-N bond cleavage on the radiolysis of aqueous solutions of amino-containing organic compounds are those in which the key role is played by reactions of monomolecular decomposition of radicals of the initial compounds.

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 Q 10 , bcarotene, lutein, zeaxanthin, a-tocopherol, a-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 Q 10 , 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 b-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.

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