LAUSR

Abstract The present study aimed to produce decyl oleate ester via enzymatic synthesis using a low-cost and totally homemade derivative prepared from chemically modified rice husks (phenyl-silica) and Geotrichum candidum lipase (LGC-I) produced by submerged fermentation. LGC-I was immobilized by physical adsorption on the phenyl-silica support and the effect of protein loading was then evaluated, and the derivative prepared using 8.13 mg protein loading, for which an immobilization yield of 54.23% and a hydrolytic activity of 121.74 ± 1.45 U/g was obtained, was selected for subsequent esterification. The decyl oleate production process was optimized using the central composite rotational design (CCRD) for two variables: derivative concentration and reaction temperature. As regards emollient production, optimal conditions are 15% (w/v) of biocatalyst at reaction temperature of 50 °C. A conversion of 78% was observed at 120 min of reaction. The prepared derivative was reused in 6 consecutive 120 min cycles and residual activity was maintained above 73.3%. The 1H NMR spectroscopy revealed that only decyl oleate was produced with no signs of by-products whatsoever, also the main spectroscopic properties of the synthesized decyl oleate was observed using the IR spectrum.