title: Integral kinetic model for studying quercetin degradation and oxidation as affected by cholesterol during heating.
abstract: The degradation and oxidation of quercetin, as affected by cholesterol during heating at 150 °C, was kinetically studied using non-linear regression models. Both TLC and HPLC were used to monitor the changes of quercetin, cholesterol and cholesterol oxidation products (COPs) during heating. The formation of COPs, including triol, 7-keto, 7α-OH and 7β-OH, was completely inhibited during the initial 30 minute heating period in the presence of 0.02% quercetin, accompanied by reduction in cholesterol peroxidation and degradation. However, the quercetin degradation or oxidation proceeded fast, with the rate constants (h(-1)) in the presence of nitrogen, oxygen and the combination of oxygen and cholesterol being 0.253, 0.868 and 7.17, respectively. When cholesterol and quercetin were heated together, the rate constants (h(-1)) of cholesterol peroxidation, epoxidation and degradation were 1.8 × 10(-4), 0.016 and 0.19, respectively. The correlation coefficients (r(2)) for all the oxidative and degradation reactions ranged from 0.82-0.99. The kinetic models developed in this study may be used to predict the degradation and oxidation of quercetin as affected by cholesterol during heating.
authors.affiliation: Department of Food Science, Fu Jen University, Taipei 242, Taiwan; E-Mails: 002604@mail.fju.edu.tw (J.T.C.); sinbaraj@yahoo.com (B.S.I.).
authors.forename: John-Tung
authors.initials: JT
authors.lastname: Chien
authors.forename: Da-Jung
authors.initials: DJ
authors.lastname: Hsu
authors.forename: Baskaran Stephen
authors.initials: BS
authors.lastname: Inbaraj
authors.forename: Bing-Huei
authors.initials: BH
authors.lastname: Chen
mesh_terms: D002784:Cholesterol / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D015227:Lipid Peroxidation; D008956:Models, Chemical; D010084:Oxidation-Reduction; D011794:Quercetin / Q000737:chemistry*
chemical_list: D002784:Cholesterol; D011794:Quercetin