Department of Chemistry "G. Ciamician" , University of Bologna , Via S. Giacomo 11 , 40126 Bologna , Italy.
J Agric Food Chem. 2019 Jun 19;67(24):6902-6910. doi: 10.1021/acs.jafc.9b01400. Epub 2019 Jun 10.
The autoxidation kinetics of stripped sunflower oil (SSO), squalene (SQ), and p-cymene ( p-C) initiated by 2,2'-azobis(isobutyronitrile) at 303 K were investigated under controlled conditions by differential oximetry in order to build reference model systems that are representative of the natural variability of oxidizable materials, for quantitative antioxidant testing. Rate constants for oxidative chain propagation ( k) and chain termination (2 k) and the oxidizability ( k/√2 k) were measured using 2,6-di- tert-butyl-4-methoxyphenol, 2,2,5,7,8-pentamethyl-6-chromanol, BHT, and 4-methoxyphenol as reference antioxidants. Measured values of k (M s)/2 k (M s)/oxidizability (M s) at 303 K in chlorobenzene were 66.9/3.45 × 10/3.6 × 10, 68.0/7.40 × 10/2.5 × 10, and 0.83/2.87 × 10/4.9 × 10, respectively, for SSO, SQ, and p-C. Quercetin, magnolol, caffeic acid phenethyl ester, and 2,4,6-trimethylphenol were investigated to validate calibrations. The distinctive usefulness of the three substrates in testing antioxidants is discussed.
采用差示氧法在 303 K 下研究了经 2,2'-偶氮二异丁腈引发的脱臭葵花籽油（SSO）、角鲨烯（SQ）和对伞花烃（p-C）的自氧化动力学，以构建可代表氧化材料自然变化的参考模型体系，用于定量抗氧化测试。使用 2,6-二叔丁基-4-甲氧基苯酚、2,2,5,7,8-五甲基-6-色满醇、BHT 和 4-甲氧基苯酚作为参考抗氧化剂，测定了氧化链式传播（k）和链终止（2k）的速率常数以及氧化率（k/√2k）。在氯苯中于 303 K 下测得的 k（M s）/2k（M s）/氧化率（M s）值分别为 66.9/3.45×10/3.6×10、68.0/7.40×10/2.5×10 和 0.83/2.87×10/4.9×10，分别为 SSO、SQ 和 p-C。研究了槲皮素、厚朴酚、咖啡酸苯乙酯和 2,4,6-三甲基苯酚，以验证校准。讨论了这三种底物在抗氧化剂测试中的独特用途。
