ripening of honey, glucose oxidase is inactivated but regains its activity if the honey is diluted. In a study by Kwakman et al, it was found that Revamil honey produced 3.47 _ 0.25 mM H2O2 in 40% (v/v) honey after 24 hours, but no H2O2 was detectable in the Manuka honey they tested, suggesting that nonperoxide factors are responsible for the antimicrobial activity of Manuka honey.