| dc.description.abstract | Increased interest in phenolic acids stems from their physiological benefits, which make them very interesting for various applications in food and pharmaceutical industries [1]. The main advantage of phenolic compounds application as natural antioxidants instead of traditionally used synthetic ones, butylated hydroxytoluen (BHT) and butylated hydroxyanisole (BHA), is found in the fact that both BHT and BHA are potential carcinogens, hence their application continuously decreases [2]. On the other hand, one of the main obstacles for their utilization in foods and cosmetics is their low solubility in emulsions and oil-based formulas as repercussion of their hydrophilic nature. Introduction of aliphatic side chain groups via enzyme-catalyzed esterification, causing solubility alternations of phenolic acids, is an adequate way for increasing their industrial application potential [3]. The aim of this research was to enable efficient enzyme-catalyzed synthesis of liposoluble phenolic esters using synthesis oleyl cinnamate as model reaction and to determine kinetic constants which are very important for process scale up. Enzyme used for all esterifications is commercial preparation of lipase B from Candida antarctica, Novozyme 435. Initial kinetic study was performed in capped vessels where different concentrations of cinnamic acid (0.1-0.7 mol dm-3), oleyl alcohol (0.1-0.7 mol dm-3) and immobilized lipase (40 mg) were mixed in isooctane and put on orbital shaker set at 55°C and 150 rpm for 6 hours. Several different models were used to fit experimentally obtained data, but the best fit was obtained when ping-pong bi-bi model was used. | sr |
