Hydroxyl radical scavenging activity was estimated
by generating the hydroxyl radicals using ascorbic acid–
iron EDTA. The hydroxyl radicals were formed by the oxidation
react with dimethyl sulfoxide (DMSO) to yield
formaldehyde, which provides a convenient method to
detect hydroxyl radicals by treatment with Nash reagent.
The hydroxyl radical scavenging activity of the isopropanol
plus water conserves of coffee is shown in Fig. 2. Coffee
conserves (both purified and crude) exhibit 80% and 92%
hydroxyl radical scavenging activity at 200 ppm. The ability
of the coffee conserves to quench hydroxyl radicals
seems to be directly related to the prevention of propaga-