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

Hydrogen peroxide plays a key role in honey antibacterial activity. The production of HO 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 HO concentration in honey. The observed variations in HO levels among honeys questioned however the direct GOx-HO 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 HO 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 HO production that change our traditional understanding of honey function as antimicrobial agent.