Main content area

Production and characterisation of enzymatically produced lauric acid esters of fructose

Sekeroglu, Gulten, Fadiloglu, Sibel, Ibanoglu, Esra
Journal of the science of food and agriculture 2002 v.82 no.13 pp. 1516-1522
dodecanoic acid, esters, fructose, high performance liquid chromatography, surface tension, triacylglycerol lipase
Lauric acid esters of fructose were produced using immobilised lipase (EC; Novozym 435). A molecular sieve was used to shift the reaction towards the synthesis. The mono-, di- and higher esters of lauric acid with fructose were obtained and analysed qualitatively and quantitatively by high-pressure liquid chromatography (HPLC). At a 5:1 molar ratio of lauric acid to fructose the amounts of monoester, diester and higher esters produced were 37, 53 and 98 mg respectively after 96 h of reaction time. After purification of the products by column chromatography the hydrophile/lipophile balance (HLB) values of fructose monolaurate and fructose dilaurate were found to be 8.95 and 5.3 respectively and their critical micelle concentration (CMC) values were calculated as 7.20 × 10−5 and 6.40 × 10−5 M respectively. The CMC values of esters obtained from the conductivity curve and the surface tension curve were significantly (P < 0.05) similar to each other. It was found that when the concentration of surfactant was increased from 0.25 to 0.50% (w/v), stabilisation of the emulsion also increased. Fructose dilaurate showed better stability than the other esters. Separation of the phases reached 70% within 30 h for the emulsion prepared with 0.50% (w/v) of this ester.