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Gladyshev M.I., Sushchik N.N., Gubanenko G.A., Makhutova O.N., Kalachova G.S., Rechkina E.A., Malyshevskaya K.K. (2014): Effect of the way of cooking on contents of essential polyunsaturated fatty acids in filets of zander. Czech J. Food Sci., 32: 226-231.Fatty acid content of raw and cooked zander (Sander lucioperca) was studied. Special attention was paid to long-chain polyunsaturated fatty acids: eicosapentaenoic, 20:5 n-3 (EPA) and docosahexaenoic, 22:6 n-3 (DHA), and also to the n-6/n-3 ratio, which are regarded as indicators of nutritive value. As found, the heat treatments, boiling, stewing and frying, including those in a convection steam oven (CSO), did not significantly decrease the content of EPA and DHA in the products. Boiling and stewing appeared to give products of a higher nutritive value, regarding the above indicators, than frying and cake preparation. Frying of zander in CSO was found to be more beneficial for nutrition compared to pan-frying. The cooked zander had higher EPA and DHA contents than many other popular food fish species, and also had a high nutritive value due to the low n-6/n-3 ratio when boiled and stewed.

Long‐chain polyunsaturated n‐3 fatty acids (LC‐PUFA), including eicosapentaenoic (EPA), and docosahexaenoic (DHA) are an essential part of human diets, but their main source, the wild fish catch, is limited. Terrestrial production animals, such as cattle, pigs, and chicken, can synthesize these compounds from the plant‐derived precursor α‐linolenic acid, and the synthesis occurs mainly in liver. We estimated the putative contribution of liver products to the LC‐PUFA supply in human nutrition, as an alternative to fish. We measured EPA and DHA contents in raw and cooked livers of the animals. Calculations of global production of EPA and DHA in the livers of these animals were done. Mean contents of LC‐PUFA in raw livers of chicken, pigs, and cattle were comparable with those in some fish. Culinary treatments of the liver did not result in a decrease of EPA and DHA contents. Global production of EPA and DHA in animals’ livers was estimated as ∼4 106 kg/year, while the global EPA + DHA supply through the wild fish catch is known to be 180 106 kg/year. Thus, liver of production animals is an additional source of LC‐PUFA for human nutrition, rather than an alternative to fish. Practical applications: Consumption of food with a high PUFA content and a low n‐6/n‐3 ratio is recommended for humans to prevent cardiovascular disease and psychiatric disorders. We found that cooked pork and beef liver is a valuable source of n‐3 LC‐PUFA in human nutrition. In contrast, cooked chicken liver had too high of a n‐6/n‐3 ratio and, thereby, had a lower nutritive value concerning n‐3 LC‐PUFA. An estimate has been made of the putative contribution of liver products of terrestrial animals to the LC‐PUFA supply as alternative to fish in human nutrition.

The aim of the study was to explore the antioxidant activity of aqueous extracts of leguminous crop seedlings - chickpea and lentils. For the study of antioxidant activity, an in vitro method of autooxidation of adrenaline in an alkaline medium was used. The process of adrenaline autooxidation was investigated as a model reaction of quinoid oxidation, proceeding through a series of intermediate stages with the formation of the final product of adrenochrome. The accumulation of the adrenaline autooxidation intermediate product - adrenalinquinone - in an aqueous-alkaline medium and in the presence of aqueous chickpea or lentil extracts was recorded using a UV 1700 spectrophotometer (Shimadzu) at a wavelength of 348 nm. It was revealed that aqueous extracts of legumes exhibit antioxidant activity. Inhibition of adrenaline autooxylation with a selected exposure time of 5 minutes in the presence of aqueous extracts of lentils was 25%, and of chickpea - 16%. The interrelation of the manifestation of the antioxidant activity of seedlings and the content of biologically active compounds with reducing properties (reducing sugars, flavonoids, vitamin C and tannins) was revealed.