SUMMARYThe composition of grape seeds from two white dessert ('Bolgar' and 'Super ran Bolgar') and two red wine Bulgarian varieties ('Mavroud' and 'Shiroka melnishka loza') was investigated. The content of proteins was established by Kjeldhal method and was found to be 6.3 -8.9%. The content of carbohydrates -calculated as the difference of mean values: 100 -(amount in percentage of oil, moisture, protein and ash) -was 65.5 -70.9%. The content of oil -by extraction with n-hexane -was 11.6 -16.5%. The content of phospholipids was determined spectrophotometrically after isolation by chromatographic methods and was found to be 0.6 -0.9%, including phosphatidylcholine, phosphatidylinositol and phosphatidic acids. The sterol content determined by gas chromatography was 0.3 -0.4% while β-sitosterol (70.0 -72.1%) and campesterol (18.5 -19.9%) were the major components. In the phospholipids and sterol esters, saturated and monounsaturated fatty acids presented higher amount than the triacylglycerols. Fatty acids of sterol esters and phospholipids were determined by gas chromatography after isolation. The quantity of palmitic acid in the phospholipid fraction was 43.4 -59.4%, the content of oleic acid was 9.0 -14.0% and the content of linoleic acid was 10.0 -24.5% while in the sterol esters, the predominant ones were mainly linoleic (40.7 -53.8%), oleic (24.9 -35.5%) and palmitic acids (13.0 -16.7%). Linoleic (68.5 -72.3%) and oleic acids (16.3 -18.7%) were found to be the main components of the triacylglycerols. The tocopherol content varied from 67.7 mg kg -1 to 290.5 mg kg -1 where α-tocopherol (74.8 -84.4%) was the predominant component. RESUMOFoi estudada a composição das grainhas de duas castas brancas ('Bolgar' e 'Super ran Bolgar') e de duas castas tintas búlgaras ('Mavroud' e 'Shiroka melnishka loza'). O teor de proteínas foi determinado pelo método de Kjeldhal, estando compreendido entre 6.3 e 8.9%. O teor de glúcidos -calculado como a diferença de valores médios: 100 -(teor em percentagem do óleo, humidade, proteína e cinzas) -foi de 65.5 -70.9%. O teor de óleo -extraído com n-hexano -foi de 11.6 -16.5%. A concentração de fosfolípidos foi determinada espectrofotometricamente após isolamento por métodos cromatográficos, sendo de 0.6 -0.9%, incluindo fosfatidilcolina, fosfatidilinositol e ácidos fosfatídicos. A fração dos esteróis, determinada por cromatografia gasosa, representou 0.3 -0.4%, sendo maioritariamente constituída por β-sitosterol (70.0 -72.1%) e por campesterol (18.5 -19.9%). Nos fosfolípidos e ésteres de esteróis, os ácidos gordos saturados e monoinsaturados apresentaram preponderância relativamente aos triacilgliceróis. A análise dos ácidos gordos foi efetuada, após isolamento, por cromatografia gasosa. Na fração fosfolipídica, a quantidade de ácido palmítico variou entre 43.4 e 59.4%, a de ácido oleico foi de 9.0 -14.0% e a de ácido linoleico foi de 10.0 -24.5%. Já nos ésteres de esteróis, observou-se predominância do ácido linoleico (40.7 -53.8%), do ácido oleico (24.9 -35.5%) e do ácido palmíti...

The changes in the content and composition of total fatty acids, phospholipids and sterol esters, and their fatty acids, and of free sterols and tocopherols in developing seeds of a selection of high oleic acid sunflower varieties grown in Bulgaria were examined over a period of 15th to 90th day after flowering by means of various chromatographic methods. Under the climatic and geographical conditions typical for the South-East Balkans phospholipid, sterol-, sterol ester-and tocopherol-species are formed practically completely in the first 15 days after flowering. Until the 90th day, only quantitative changes were detected to give a product with 65% oil content, 1% phospholipids, 0.3% total sterols and 0.09% tocopherols. Oleic acid is the main component in all acyl derivatives, reaching 85% of the total fatty acids while palmitic and stearic acid content is about 4% each. The product is a good quality HOSO with beneficial content of FA and good prospects as a salad and cooking oil.

Low‐calorie structured lipids that contain medium‐chain fatty acids in the sn‐1 and sn‐3 positions of the glycerol backbone, and long‐chain fatty acid in the sn‐2 (MLM type) were synthesized in one‐step acidolysis of walnut oil with caprylic acid. Caprylic acid residues were incorporated selectively into sn‐1,3 positions of triacylglycerols using 1,3‐specific immobilized lipases from Rhizomucor miehei (Lipozyme) and Rhizopus delemar (PP‐RhDL) as catalysts. Under the optimal reaction conditions, we achieved an excellent yield of the desired MLM‐type structured lipids (97 mole % with Lipozyme and 96.4 mole % with PP‐RhDL). The synthetic activity of PP‐RhDL was not influenced by the reaction medium whereas the Lipozyme was more effective in hexane than in solvent‐free medium. The same degree of conversion of initial triacylglycerols was observed for the two enzymes in four consecutive reaction cycles. The amount of MLM‐type structured lipids, however, decreased with each following cycle at the expense of mono‐substituted with caprylic acid triacylglycerols (MLL type). Practical Applications Structured lipids (SLs) that contain medium‐chain fatty acids in the sn‐1 and sn‐3 positions of the glycerol backbone, and long‐chain fatty acids in the sn‐2 (MLM type) are known to improve liver function, minimize risk of infections, and reduce the number of gastrointestinal complications in patients undergoing major abdominal surgery and are used in clinical nutrition as well as specialized food for athletes because they provide fast energy supply. After an enzymatic modification of walnut oil, high yield of SLs with caprylic acid residue in the sn‐1 and sn‐3 positions of the glycerol backbone and long‐chain fatty acid residue in the sn‐2 position of triglycerides was obtained.