On the nature of non-peroxide antibacterial activity in New Zealand manuka honey

Some conclusions, which exist in the literature about the nature of non-peroxide antibacterial activity in manuka honey, have been revisited. The stability of non-peroxide antibacterial activity in manuka honey at basic pH was investigated. At pH 11 antibacterial activity was immediately and irreversibly destroyed. This indicates that it is not possible to carry out chromatography of honey solutions at elevated pH with the intent to isolate the active fraction. The effect of 10-fold excess of catalase upon the antibacterial assay was examined. No statistical difference in the outcome was observed between the normal amount of catalase and the 10-fold excess. This indicates that non-peroxide antibacterial activity in manuka honey is not likely to be due to residual hydrogen peroxide.