Lipase-catalysed synthesis of natural aroma-active 2-phenylethyl esters in coconut cream

The aim of this research was to study the feasibility of biosynthesising natural aroma-active 2-phenylethyl esters in coconut cream via biocatalysis. Five commercial fungal lipases (Palatase 20 000L, Lipase AYS “Amano”, Lipase A “Amano” 12, Piccantase A and Piccantase AN) were screened for their ability to produce 2-phenylethyl hexanoate and 2-phenylethyl octanoate from coconut cream supplemented with natural 2-phenylethanol. Palatase 20 000L and Lipase AYS “Amano” showed the greatest potential for the synthesis of 2-phenylethyl esters. The biosynthetic reaction by the lipase Palatase 20 000L was further studied under different temperature, pH, enzyme and substrate concentrations, with maximum ester synthesis obtained at 9% v/v 2-phenylethanol and 2.15–8.60 mg enzyme protein/100 ml of reaction mixture. A temperature range of 30–53 °C and a pH range of 5.2–8.5 had little effect on the lipase Palatase activity, respectively. The ester-synthesising reaction appeared to proceed by both alcoholysis and esterification.