CHARACTERIZATION OF THE TRIGLYCERIDIC STRUCTURE OF SAFOU PULP OIL (DACRYODES-EDULIS)

Abstract

The triacylglycerols (TAGs) of the pulp of safou (Dacryodes edulis) were first fractionated by high-performance liquid chromatography (HPLC) using a column packed with silica impregnated with silver ions (Ag+) into 13 classes of increasing unsaturation. The 5 major classes of TAGs were again fractionated by reversed-phase HPLC according to carbon number. Each class contained one major TAG (more than 95% of the class TAGs) which was collected and submitted to partial deacylation by porcine pancreatic lipase. The 2-acyl-sn-glycerols (sn2-MAGs) formed were isolated by thin-layer chromatography and their constituent fatty acids were analyzed by gas-liquid chromatography. The proportion of 11 TAGs whose fatty acid at the sn2-position was known were determined. These 11 TAGs together amounted to more than 90% of the total TAGs. The major (> 15%) TAGs were : 2-oleoyl-1(3)-dipalmitoyloleoyl-sn-glycerol (16:0-18:1-16:0 = 27.1%), 2-oleoyl-1(3)-palmitoytoleoyl-sn-glycerol (16:0-18:1-18:1 = 21.7%) and 2-linoleoyl-1(3)-dipalmitoyloleoyl-sn-glycerol (16:0-182-16:0 = 16.2%). Twenty one other minor TAGs, whose fatty acid positional distribution was unknown, were also identified and quantified. They only represented 7.5% of the total.