Hydroxyl Radical Scavenging Ability of Instant Coffee Evaluated by ESR Spin Trapping

Abstract

We evaluated the hydroxyl radical scavenging ability of instant coffee by the ESR spin trapping method, using 5-(2,2-dimethy-1,3-propoxycyclophosphoryl)-5-methyl-1-pyrroline N-oxide (CYPMPO) as the spin tapping reagent. This method generated very pure hydroxyl radicals by illuminating a phosphate buffer solution containing H₂O₂ and CYPMPO with an Hg-Xe arc lamp. The ESR adduct signal was sensitive and very stable. We conclude that instant coffee had high hydroxyl radical scavenging ability.