STUDY OF FATTY ACID COMPOSITION OF NATURAL SWARDS IN THE REGION OF CENTRAL BALKAN MOUNTAINS

Fatty acid content in herbaceous vegetation of a mountain meadow of the Agrostis capillaris - Festuca fallax type located at the altitude of 1000 m and a high-mountain matgrass pasture of the Nardus stricta type at 1500 m above sea-level was studied. Percentage participation of grasses, legumes and miscellaneous herbs, as well as that of predominant herbaceous species in the plant biocenoses was recorded. It was found that the grasses prevailed in both swards, participating on average with 87.86% in the meadow type and with 95.10% in the pasture one.Fatty acid profile of plant fat in the herbaceous biomass was studied by fat extraction, methylation of samples and separation of methyl esters of fatty acids from the other lipid fractions through thin-layer chromatography. The fatty acids were determined by means of a gas chromatograph. The content of saturated fatty acids in the meadow type was 33.97% and in the pasture one 37.65%. The quantity of monounsaturated fatty acids in the meadow sward was 21.47% higher than that in the high-mountain pasture. Among the essential fatty acids, the highest value was found for linolenic acid (source of CLA in milk), which was 17.86% higher in the biomass at 1500 m a.s.-l. The values of the polyunsaturated fatty acids in the studied swards were similar, 43.15% and 43.83%, respectively and were greater, as compared to the other two groups. The high content of essential fatty acids in the natural swards is of great importance for the metabolism in animal organism and for their entering, through the animal foods, into the human organism.