APPLICATIONS OF CHROMATOGRAPHIC TECHNIQUES TO EVALUATE ENZYMATIC-HYDROLYSIS OF OXIDIZED AND POLYMERIC TRIGLYCERIDES BY PANCREATIC LIPASE IN-VITRO

With the aim of studying the susceptibility to enzymatic hydrolysis of oxidized and polymeric triglycerides (TG) that are formed during fryi ng, various chromatographic techniques were applied in combination, i. e., adsorption chromatography, high-performance size-exclusion chromat ography (HPSEC), and thin-layer chromatography-flame ionization detect ion (TLC-FID). Polar fractions, isolated by adsorption chromatography from thermoxidized trilinolein as model system, and real used frying f ats and oils, were analyzed by HPSEC before and after incubation with pancreatic lipase in vitro. Also, the influence of degradation level o f used frying oils on hydrolysis of intact TG was investigated with th e additional aid of TLC-FID. Results showed the high hydrolysis rate o f oxidized TG monomers in contrast to the significant discrimination o f pancreatic lipase against TG dimers and, particularly, TG polymers. On the other hand, hydrolysis of intact TG can be affected by the pres ence of dimers and polymers in abused frying oils.