HPLC evaluation of the minor lipid components of by-products resulting from edible oil processing

Abstract

An analytical evaluation of some by-products resulting from edible oil refining processing steps has been carried out. By-product samples were taken from four different local refineries that apply chemical refining technology. Pretreatment of the representative samples of the by-products were done prior to analysis followed by chromatographic isolation and derivatization of the minor components, namely, free and acylated sterol (FS and AS) as well as free and acylated sterylglycosides (FSG and ASG). However, tocopherols were directly determined in the pretreated samples. HPLC, using different detectors, was carried out for the determination of these minor components. Several authors have focused on the analysis of sterols and sterol esters, as well as tocopherols in the refining byproducts; however sterylglycosides, as biologically important components, have not been dealt with. This study throws light on the by – products enriched with certain minor components to be possibly utilized as sources for such components. Also, the role of the conditions of the refining steps followed in removing these valuable minor components from oils was discussed. It was found that soapstock samples contained various amounts of total tocopherols ranging from 80 to 230ppm; total FS and AS ranged from 240 to 4000 mg/100g while total FSG and ASG ranged from 1120 to 6375 mg/100g. In the case of deodorization distillate samples total tocopherols ranged from 960 to 7360ppm; total FS and AS ranged from 1020 to 4160 mg/100g and total FSG, ASG ranged from 395 to 880 mg/100g.

Keywords

• acylated sterols
• by-products
• free sterols
• plc
• analysis
• sterylglycosides
• tocopherol