Impact of Storage on Honey Antibacterial and Antioxidant Activities and their Correlation with Polyphenolic Content

Abstract

The quality of honey may be affected during storage. The purpose of this study was to assess the impact of storage of nine Algerian honey samples on its antibacterial activity and antioxidant effect. The antibacterial activity of honey samples was evaluated by both the agar well diffusion and micro-broth dilution assays. The antioxidant activity was performed by using in vitro scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP). All the analyses were performed before storage and after every six months of storage in the dark at room temperature (24 ± 4°C). All the honey samples showed a decrease in antibacterial activity after six months of storage except for the honey sample 2. Indeed, there were no significant variations in the total polyphenolic content and DPPH values before and after storage, except for honey sample 6. However, there was a significant decrease in the antioxidant capacity measured by FRAP assay (P = 0.0002). There was a strong correlation between the total polyphenolic content of honey and its antioxidant activity and a moderate correlation with the antibacterial activity. The storage of honey in the dark at room temperature for 18 months influences the quality of honey. However, further investigations are required to strengthen this argument.