Application of partially concentrated Candida rugosa lipase in the enzymatic synthesis of geranyl acetate in organic solvent

•Candida rugosa produced high level lipase using agroindustrial residues.•11.7-fold concentration factor for Candida rugosa lipase were obtained with acetone precipitation.•Candida rugosa lipase application resulted in high yield and productivity of geranyl acetate.•79% of yield for geranyl acetate synthesis were obtained in optimized conditions.

Esters of terpinyl alcohols are substances used for adding flavor to several products because of their organoleptic properties. The enzymatic synthesis of these substances is more eco-friendly than conventional chemical synthesis. The aim of this study was to evaluate the concentration of Candida rugosa lipase by precipitation with acetone followed by lyophilization and application of the enzyme in the synthesis of geranyl acetate in organic solvent. The steps of enzyme concentration and ester synthesis were performed by applying central composite rotational designs (CCDR) in order to evaluate the process variables. The best condition for the concentration of Candida rugosa lipase was at −10 °C and 80% (w/w) acetone saturation, which resulted in 198 U/mL of enzyme activity and 11.7-fold concentration factor (CF). The optimum condition for the synthesis of geranyl acetate was at 45 °C, 12.5% (w/w) (lipase/geraniol mass ratio), 1:1.5 (geraniol: vinyl acetate molar ratio) at 8 h of reaction in organic solvent (n-hexane). Such condition resulted in 79% yield and productivity of 9.88%/h in ester production. The results obtained demonstrate that it is possible to obtain high yields in the synthesis of geranyl acetate even with the use of non-commercial partially concentrated lipase in the free form when using optimized process conditions.