ANALYSIS OF MODIFIED FRYING OILS BY HIGH-PERFORMANCE SIZE-EXCLUSION CHROMATOGRAPHY-DUAL VISCOMETRIC/REFRACTOMETRIC DETECTION

Authors: Abidi, Sharon; WONG, W - VISCOTEK CORPORATION; WILLIBEY, W - VISCOTEK CORPORATION; Warner, Kathleen; Rennick, Kathy

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/10/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: To evaluate the frying performance of various frying oils, including genetically modified oils, we characterized nonvolatile components of the oils. Several frying oil samples from high oleic sunflower oil and cottonseed oil were analyzed for nonvolatile components by high performance size exclusion chromatography (HPSEC) with dual viscometric (VIS)/ refractometric (RI) detection. The nonvolatile components of whole oils and polar fractions were separated with three mixed bed polystyrene/divinylbenzene columns and their molecular weights were directly determined using a universal calibration technique with the combination of VIS/RI detector system. Detector alignment of the two VIS/RI signals in the universal calculation software was carried out on a narrow polystyrene standard. HPSEC of oil samples of different frying times (0-40 hrs) yielded triglyceride derived monomer, dimer, trimer, and tetramer plus high polymers of variable molecular weights and compositions The method provides potential analytical utility in the quantitation of frying oil components without isolation of polar fractions. The new detection technique also allowed characterization of linear or nonlinear polymer structures. The results of this study showed that, in addition to frying variables, the type of oil variety had significant impact on the composition of nonvolatile degradation products of the frying oils analyzed.