High-Throughput Quantitation of Peroxyl Radical Scavenging Capacity in Bulk Oils
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- 作者：Kai Xin Hay ; Viduranga Yashasvi Waisundara ; Mark Timmins ; Boxin Ou ; Kathleen Pappalardo ; Nancy McHale ; and Dejian Huang
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2006
- 出版时间：July 26, 2006
- 年：2006
- 卷：54
- 期：15
- 页码：5299 - 5305
- 全文大小：95K
- 年卷期：v.54,no.15(July 26, 2006)
- ISSN：1520-5118
文摘
Autoxidation of methyl linoleate (8:2 mixture with decane, 37 
C) was induced by 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN, 17.7 mM) and the kinetics of oxygen consumption monitored using a96-well microplate coated with an oxygen-sensitive fluorescence probe, a ruthenium dye, embeddedin a silicone matrix at the bottom of the microplate. The probe does not participate in the reaction;instead, its fluorescence intensity is inversely proportional to the solution oxygen concentration as itchanges during oxidation. In the absence of antioxidants, the oxidation rate has a linear relationshipwith the square root of the initiator concentrations. This is in agreement with theoretical autoxidationkinetics equations. In the presence of tocopherol-type antioxidants, a sharp lag phase appears. Thequantitation of the antioxidant capacity is achieved using the area under the curve (AUC) approach.The assay has a 2 h running time, a linearity range from 1.56 to 18.7 
M (Trolox), and a limit ofquantitation at 2.7 M Trolox equivalency. The peroxyl radical scavenging capacities of several cold-pressed and organically grown plant seed oils were quantified along with the tocopherol concentrationsof the oils. Tocopherols contribute only a fraction of the peroxyl radical scavenging capacity of theoils, and there is poor correlation between total tocopherol concentrations and radical scavengingcapacity, suggesting that the antioxidant capacity of oils is due not only to tocopherols but also toother lipid-soluble antioxidants.Keywords: High-throughput; antioxidant; fluorescence; kinetics; seed oils; tocopherols
C) was induced by 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN, 17.7 mM) and the kinetics of oxygen consumption monitored using a96-well microplate coated with an oxygen-sensitive fluorescence probe, a ruthenium dye, embeddedin a silicone matrix at the bottom of the microplate. The probe does not participate in the reaction;instead, its fluorescence intensity is inversely proportional to the solution oxygen concentration as itchanges during oxidation. In the absence of antioxidants, the oxidation rate has a linear relationshipwith the square root of the initiator concentrations. This is in agreement with theoretical autoxidationkinetics equations. In the presence of tocopherol-type antioxidants, a sharp lag phase appears. Thequantitation of the antioxidant capacity is achieved using the area under the curve (AUC) approach.The assay has a 2 h running time, a linearity range from 1.56 to 18.7 M (Trolox), and a limit ofquantitation at 2.7 M Trolox equivalency. The peroxyl radical scavenging capacities of several cold-pressed and organically grown plant seed oils were quantified along with the tocopherol concentrationsof the oils. Tocopherols contribute only a fraction of the peroxyl radical scavenging capacity of theoils, and there is poor correlation between total tocopherol concentrations and radical scavengingcapacity, suggesting that the antioxidant capacity of oils is due not only to tocopherols but also toother lipid-soluble antioxidants.Keywords: High-throughput; antioxidant; fluorescence; kinetics; seed oils; tocopherols