Esterification reaction in SC-CO2 catalyzed by lipase produced with corn steep liquor and Minas Frescal cheese whey

Abstract

Corn steep liquor (CSL) from the processing of starch and cheese whey (CW) from the production of Minas Frescal cheese were used to produce the lipase of Geotrichum candidum. This enzyme show activity of 19.87 U/mL and productivity of 0.83 U/mL.h in optimally conditions (5% CSL, 40% CW and a pH 6.0). This lipase was a catalyst in the esterification reaction of oleic acid (OA) with methanol (MeOH) in supercritical medium (SC-CO2), in solvent-free medium and with hexane. The use of SC-CO2 as a solvent increased the reaction yield by 3 times, reaching 37.73% with a molar ratio of OA: MeOH at 1:3, 2.5 U/g, at 30 °C and 30 MPa. The objective of this study was to evaluate the activity of the lipase produced using CSL and CW and to measure the catalytic capacity of the lipase in the esterification reaction in a different medium, that demonstrate the superiority of the esterification reactions using SC-CO2.