A current perspective on hydrogen peroxide production in honey. A review

Hydrogen peroxide plays a key role in honey antibacterial activity. The production of H2O2 in honey requires glucose oxidase (GOx) that oxidizes glucose to gluconolactone and reduces molecular oxygen to hydrogen peroxide. The content of GOx of honeybee origin was believed to be the main predictor of H2O2 concentration in honey. The observed variations in H2O2 levels among honeys questioned however the direct GOx-H2O2 relationship and left its absence opened for exploration. Here, we evaluated principal causes underlying the imbalance in the quantitative enzyme-product relationship with respect to: (a) enzyme and the product inactivation or destruction by honey compounds; (b) non-enzymatic pathway of H2O2 formation, and (c) a potential contribution of enzymes with GOx activity originating from nectars and microorganisms inhabiting honey. We also bring new facts on the relationship between honey colloidal structure and H2O2 production that change our traditional understanding of honey function as antimicrobial agent.