Synthesis of Octyl Palmitate in Various Supercritical Fluids

Abstract

Octyl palmitate was enzymatically synthesized from palmitic acid and octanol. The synthesis of octyl palmitate was investigated in three supercritical fluids, namely, carbon dioxide, methane, and ethane, using three different enzymes. The effects of temperature, initial water content, alcohol concentration, and enzyme loading on the conversion were determined. Among the enzymes, Novozym 435 (immobilized) catalyzed the reaction, resulting in the highest conversion compared to the other lipases, irrespective of the solvent used. Further, Novozym 435 was active over a wider range of temperatures (35-65 °C) compared to the other two enzymes. The lowest esterification (76%) was obtained in supercritical carbon dioxide, while the highest esterification was obtained in supercritical methane (85%). The results thus indicate that for this reaction, among the systems investigated, supercritical methane and Novozym 435 are the best supercritical fluid and enzyme, respectively.

Synthesis of isoamyl laurate and isoamyl stearate in supercritical carbon dioxide

“…These results are consistent with earlier studies for the synthesis of ethyl palmitate (21), octyl palmitate (24), and various flavor ester of isoamyl alcohol (23).…”

“…The highest conversion was obtained when the temperatures ranged between 40-45°C. Previous studies, on the enzymatic synthesis of esters in SCCO 2 (21,(23)(24) indicate that the optimum temperature can vary between 45 and 55°C.…”

“…The conversion decreases trends as the reactions are shifted toward reactant side with addition of water. An optimum water concentration was observed for isoamyl acetate (10), ethyl palmitate (21), octyl palmitate (24), glycidyl butyrate (16), and enzymatic transesterification (25) of …”

Sub- and supercritical fluid technology applied to food waste processing

“…These esters have cosmetic, pharmaceutical and food applications. Some examples are the oleic acid for ethyl oleate production [22], palmitic acid for octyl palmitate synthesis [23,24] and myristic acid for myristic acid methyl ester [25].…”

Continuous kinetic resolution catalysed by cross-linked enzyme aggregates, ‘CLEAs’, in supercritical CO2

“…Despite this disadvantage, Novozym 435 has become the biocatalyst most often investigated in scCO 2 because of its proven activity and stability. 29,33,34 Applications include kinetic resolutions with excellent yields and selectivities, and the ability to scale up from batch to continuous supercritical flow systems. 7 More recently, cross-linked enzyme aggregates (CLEAs){ have been prepared by Sheldon et al 35 In a CLEA, the enzyme is precipitated from aqueous solution by adding a salt or a water-miscible organic solvent to form aggregates which are subsequently cross-linked with a bi-functional agent, such as glutaraldehyde 36,37 or dextran polyaldehyde.…”