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 (kp) and chain termination (2kt) and the oxidizability (kp/2kt) 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 kp (M-1 s-1)/2kt (M-1 s-1)/oxidizability (M-1/2 s-1/2) at 303 K in chlorobenzene were 66.9/3.45 × 106/3.6 × 10-2, 68.0/7.40 × 106/2.5 × 10-2, and 0.83/2.87 × 106/4.9 × 10-4, 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.
Calibration of Squalene, p-Cymene, and Sunflower Oil as Standard Oxidizable Substrates for Quantitative Antioxidant Testing / Baschieri A.; Pizzol R.; Guo Y.; Amorati R.; Valgimigli L.. - In: JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY. - ISSN 0021-8561. - STAMPA. - 67:24(2019), pp. 6902-6910. [10.1021/acs.jafc.9b01400]
Calibration of Squalene, p-Cymene, and Sunflower Oil as Standard Oxidizable Substrates for Quantitative Antioxidant Testing
Baschieri A.Investigation
;GUO, YAFANGInvestigation
;Amorati R.Investigation
;Valgimigli L.
Supervision
2019
Abstract
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 (kp) and chain termination (2kt) and the oxidizability (kp/2kt) 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 kp (M-1 s-1)/2kt (M-1 s-1)/oxidizability (M-1/2 s-1/2) at 303 K in chlorobenzene were 66.9/3.45 × 106/3.6 × 10-2, 68.0/7.40 × 106/2.5 × 10-2, and 0.83/2.87 × 106/4.9 × 10-4, 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.