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New sources of docosahexaenoic acid have recently been investigated aiming at infant formula fortification and dietary supplementation, among which the single cell oil with 40-50% of this acid. For this purpose, such an oil was blended with caprylic acid in amount substance ratio ranging from 1:1 to 5:1 and the blends were interesterified using either Novozym 435 or Lipozyme TL IM as the catalyst. The influence of the amount of excess free caprylic acid in the substrate, as well as the type of enzyme on the triacylglycerol rearrangement resulting from the synthesis of the structured lipids were evaluated. The regiospecific lipase Lipozyme TL IM seemed to induce transesterification among single cell oil triacylglycerols preferably by acidolysis with caprylic acid, which was directly proportional to the ratio of this acid in the substrate. In reactions catalyzed by the non-regiospecific lipase Novozym 435, a higher incorporation of caprylic acid into single cell oil triacylglycerols was observed than when using Lipozyme TL IM, independently of the oil/caprylic acid molar ratio. These results revealed the importance of combining the choice of the type of lipase, either regiospecific or not, with the amount ratios of free fatty acids and the substrate in acidolysis when aiming to produce structured lipids as a source of docosahexaenoic acid., Pozadina istraživanja. U posljednje se vrijeme istražuju novi izvori dokosaheksaenoične kiseline koji se mogu upotrijebiti za obogaćivanje hrane za dojenčad i dodatke prehrani, među ostalim i mikrobni lipidi što sadržavaju 40-50 % te kiseline. Eksperimentalni pristup. U tu su svrhu mikrobni lipidi pomiješani s kaprilnom kiselinom u molarnom omjeru od 1:1 do 5:1, a zatim su smjese interesterificirane pomoću katalizatora, lipaze Novozym 435 ili Lipozyme TL IM. Ispitan je utjecaj suviška slobodne kaprilne kiseline u supstratu i vrste enzima na promjenu strukture triglicerida tijekom sinteze strukturiranih lipida. Rezultati i zaključci. Regiospecifična lipaza Lipozyme TL IM izgleda potiče transesterifikaciju triglicerida u mikrobnim lipidima kaprilnom kiselinom, proporcionalno udjelu te kiseline u supstratu. U reakcijama kataliziranim nespecifičnom lipazom Novozym 435 u trigliceride mikrobnih lipida ugrađeno je više kaprilne kiseline nego pri uporabi lipaze Lipozyme TL IM, neovisno o molarnom omjeru lipida i kaprilne kiseline. Novina i znanstveni doprinos. Dobiveni rezultati pokazuju da je za proizvodnju strukturiranih lipida kao izvora dokosaheksanoične kiseline bitno odabrati pravu kombinaciju regiospecifične ili nespecifične lipaze i udjela slobodnih masnih kiselina u podlozi za kiselinsku hidrolizu.