Identification and quantification of steryl glucosides in biodiesel

This paper discusses the nature and the chemical identification of a white, solid and insoluble residue isolated during the production of biodiesel, using palm or soybean oil as starting material. Using different isolation, purification and characterisation techniques, the solid was identified as a mixture of phytosteryl glucosides. A simple method for the quantitative evaluation of steryl glucoside (SG) concentrations in biodiesel samples is presented and discussed. Some preliminary results about the average concentration in biodiesel and about the solubility limits of SG are presented. The final section of this paper is dedicated to the impact of different crude oil refining techniques before the biodiesel synthesis reaction on the final SG concentration in biodiesel.