The Bio-imprinting Of The Lipase And The Lipase Catalyzed Esterifications

Ethyl Hexanoa are high valuable and commercial demand flavour compounds, and are widely used in the food, beverage and pharmaceutical industries etc. Natural flavour esters extracted from plant sources are often in short supply or expensive. Moreover, flavour varies from region to region. Most of these esters can also be produced chemically by acid-catalyzed condensation of an alcohol and an acid atelevatedtemperatures,however, this way has many drawbacks, such as more byproduct, difficulty postprocessing and low product quality. Because of the mild reaction condition, less side reactions and environment pollution of enzyme-catalyzed reactions, utilization of enzymes is of great interest both in economical and social benefits. Bioimprinted enzyme, crosslinked imprited enzyme and enzyme synthesized in reverse micelle were used in this article. The activity of enzemy increase than free enzemy, and the standbility of enzemy is also enhanced. The production efficiency is increased ,the production time was reduced and the production cost was decreased.The main contents are as follow:1. The synthesis of ethyl hexanoa catalyzed by candida rugosa lipase (CRL) in organic solvents was studied. The effects of reaction time, organic solvent, substrate concentration, and the molar ratio of acid to alcohol on the enzymic synthesis of ethyl hexanoa reaction were examined systematically. At the same time, the structure, purity and molecular weight of the synthesized product was also characterized carefully by IR , GC and GC-MS modern techniques.The experimental results showed that the synthesized product was ethyl hexanoa, its molecular weight was 144, and the purity of the synthesized product reached 96.91 %. While the esterification was carried out for 48 hours using heptane as reaction medium, the reaction temperature was 40℃,the molar ratio of acid to ethanol was 1:1.3, and the yield of the esterification reached 94.6%.2. The ethyl hexanoa was synthesized in reverse micelle catalyzed by CRL. The effects of reaction temperature, organic solvent, amount of water and the pH value of solvent on the enzymeic synthesis of ethyl hexanoa reaction were examined systematically. The reaction medium was heptane, pH value of solvent was 7.2, the reaction temperature was 40℃and W0=8. The activity of enzemy in reverse micelle increase 3 times as it in organic medium, and the standbility of enzemy is also enhanced.3. The ethyl hexanoa was synthesized in organic medium, catalyzed by Crosslinked imprited CRL. The experimental results show that the reaction medium was heptane, the reaction temperature was 40℃, and the amount of water was 80μL. The standbility of Crosslinked imprited enzemy is greatl enhanced.4. The ethyl hexanoa was synthesized in organic medium, catalyzed by bioimprinted CRL(Candida rugosa lipase). The structure and molecular weight of the synthesized product was also characterized by IR and GC-MS techniques. The experimental results show that the synthesized product was ethyl hexanoa. The increase in activity was dependent on the amount of water, the solvent type and the imprint molecule itself. The reaction medium was heptane, the reaction temperature was 40℃, and the amount of water was 80μL. The actvityof bioimprinted enzemy increase more 6 times than free enzemy.