Abstract
In the stomach and the esophagogastric junction, nitric oxide (NO) generated by reduction of nitrite demonstrates pathophysiological effects. In this study, generation rate of NO via the reduction of nitrite in acidic condition with antioxidant-containing drinks were investigated in regard to the antioxidative capacity of the drinks. The NO concentration was measured using an NO-selective electrochemical sensor. ORAC, DPPH and FRAP assays were used for the evaluation of antioxidative capacity. Sample drinks studied were vegetable juice, coffee, and Japanese green tea.Both the NO generation rate and the antioxidative capacity were higher in coffee and green tea than vegetable juice. The NO generation rate were positively correlated with the antioxidative capacity measured by ORAC, DPPH and FRAP assays. Coffee and green tea were rich in polyphenols, most likely promoting the reduction of nitrite to NO.In conclusion, ORAC, DPPH and FRAP assays seem to be good indices for the nitrite reduction capacity of antioxidant-containing drinks.
