A semi-micro flow injection analysis (SMFIA) method for evaluation of quenching effect of food additive antioxidants or health foods on peroxynitrite (ONOO(-)) is described. The injected sample was carried with phosphate buffer containing NaNO(2), mixed with a trigger solution to generate ONOO(-) and then detected CL generated after mixing with luminol solution. Selective chemiluminescence caused by ONOO(-) in this generation system was confirmed by catalase treatment. Ascorbic acid (ASA), Trolox and ascorbyl palmitate (ASP) were used as food additive antioxidants. EC(50) values of ASA, Trolox and ASP were 2.6, 6.4 and 43 µg/mL, respectively. The amount of reagents required for an assay by this SMFIA system could reduce the time by a third compared with the conventional method previously reported. Furthermore, as an application of the proposed method, the quenching effect of commercially available Noni (Morinda citrifolia) juices was evaluated.
Copyright © 2010 John Wiley & Sons, Ltd.