Thermal degradation kinetics of lutein in oils during heating

HPLC-DAD analysis was carried out to monitor variations of lutein in oils over the heating time to know the rule of degradation, which could provide some instruction to the improvement of oil, fried food process and the development of oil products containing lutein.Variations of lutein in soybean oil and palm oil at 130, 150, 170, 190℃ were analysised by C30-HPLC-DAD and calculated kinetic parameters respectively.The thermal degradation of lutein was followed a first-order kinetic model.For all heating treatments, the dimensionless concentration of all- (E) -lutein and its (Z) -isomers decreased as a function of temperature and heating time.Compared with palm oil at the same temperature, lutein rentention in soybean oil was greater.But the degradation of these compounds in two oils at 190℃ was both severe.In one kind of oil at the same temperature, (Z) -isomers degradation rates were greater than all- (E) -lutein and (13Z/13'Z) -lutein was more easy to degrade than (9Z/9'Z) -lutein.