The lipase-catalyzed synthesis of fatty acid fructose esters in organic media and in supercritical carbon dioxide

Abstract

Sugar fatty acid esters are biodegradable surface active compounds in foodstuffs and cosmetics or Pharmaceuticals. They have potential in replacing pollutant chemically synthesized surfactants. The enzymatic synthesis of fructose palmitate catalyzed by Candida antarctica B lipase was performed in different organic media in a batch reactor at atmospheric pressure. The influence of the organic solvent and temperature on the esterification was studied. Since supercritical carbon dioxide (SC CO2) has several advantages over organic solvents, such as high reaction rate, high mass transfer n?n-toxicity, non-flammability and low price, it was also chosen as a reaction medium for fructose palmitate production. The influence of temperature on immobilized lipase activity was studied at 10 MPa and the results were compared to the results obtained from reactions performed at atmospheric pressure under the same reaction conditions. The highest conversion (67%) was obtained after 24 hours of reaction in SC CO2 at 80?C. A change of the particle size distribution and morphology of the untreated lipase and lipase treated with 2-methyl 2-butanol and SC ??2 was observed.Estri secera i masnih kiselina su biorazgradive povrsinski aktivne materije cija je primena znacajna u proizvodnji hrane, kozmetickih preparata i lekova. To su potencijalne supstance koje se mogu iskoristiti umesto nekih drugih hemijski sintetizovanih povrsinski aktivnih materija koji se danas smatraju da su zagadjivaci zivotne sredine. Enzimska sinteza palmitata fruktoze katalizovane lipazom Candida antarctica B analizirana je u sarznom reaktoru pod atmosferskim pritiskom u prisustvu razlicitih organskih rastvaraca pri cemu je proucavan uticaj organskog rastvaraca i temperature na brzinu esterifikacije, s obzirom da natkriticni ugljen dioksid (SC CO2) poseduje znacajne prednosti u odnosu na klasicne organske rastvarace jer se u slozenim procesima moze uvecati brzina hemijske reakcije kao i brzina prenosa mase u prisustvu SC CO2. Nadalje ovaj ugusceni fluid je netoksican, nezapaljiv i moze se nabaviti po niskoj ceni te je izabran kao medijum za reakciju esterifikacije fruktoze i palmitinske kiseline i dobijanja palmitata fruktoze. Uticaj temperature na brzinu esterifikacije u prisustvu imobilisane lipaze proucavan je na 10 MPa i dobijeni rezultati su uporedjivani sa rezultatima esterifikacije pod atmosferskim pritiskom na istim temperaturama. Najveca konverzija od 67% je ostvarena nakon 24 h kada je reakcija esterifikacije realizovan? na 80?C u prisustvu SC CO2. Ispitivan je uticaj raspodele velicine cestica i morfologije netretirane i tretirane lipaze sa 2-metil 2-butanolom i SC CO2 na brzinu procesa esterifikacije fruktoze i palmitinske kiseline.