Isolation and characterization of wax esters in meadowfoam oil

Meadowfoam oil has potential use in the cosmetic industry due to its long chain fatty acids. However, particulates that form when the oil is stored could create problems in this application. Particulate matter found in refined meadowfoam oil samples was isolated by first centrifugation and then crystallization from acetone. The white crystalline solid had a melting point of 77 degrees-78 degrees C, and was characterized as a mixture of wax esters by H-1 nuclear magnetic resonance (NMR), C-13 NMR and infrared (IR) analysis. Gas chromatography (GC) analysis of the wax esters indicated a distribution of esters from C-44 to C-56 including odd chain esters. Base hydrolysis of the wax ester and GC analysis of the fatty methyl esters and fatty alcohols indicated a mixture of saturated methyl esters from C-16 to C-32 including small amounts of the odd-chain methyl eaters C-21-C-29 with the predominate methyl ester being C-24. The alcohol portion of the wax esters contained saturated chain lengths of C-20-C-30 including odd chains of C-21-C-29. The main alcohol component was saturated C-24 alkanol. GC-MS (mass spectroscopy) confirmed the GC assignments. A normal phase high performance liquid chromatography (HPLC) technique was developed to determine the amount of wax ester (0.06% to 0.12%) in various types of refined meadowfoam oil.