Evaluation of the changes in physicochemical and antioxidant properties of honey during storage

Abstract

Background Despite having a lot of information about the physicochemical and antioxidant properties of honeys from different geographical regions, there is only limited information about the changes in these characteristics during long-term storage of honey. Hence, this study was conducted to evaluate these changes in five different types of honey, including alfalfa, milkvetch, lotus, thyme, and multifloral honeys, during one year of storage at room temperature.MethodsSamples were analyzed for pH, free acidity, Ash, moisture, electrical conductivity, hydroxymethylfurfural, color, total phenolic content, DPPH radical-scavenging activity and ferric reducing antioxidant power.ResultsChanges were more or less observed in all the physicochemical characteristics of honeys during the storage period. However, these changes did not exceed the maximum acceptable limits and after one-year of storage, the physicochemical properties of all types of honeys were within the standard limits except for HMF content in multifloral honey (43.89 mg/kg). Regarding the antioxidant capacity of honeys, our results showed 38.92-73.3 % decrease in DPPH radical scavenging activities and 43.29-67.0 % decrease in FRAP values of different types of honeys during the storage period.ConclusionFrom the nutritional point of view, decrease in the antioxidant capacity of honeys is of particular importance. Therefore, these levels of reduction in antioxidant capacity could certainly affect the nutritional and health benefits of honey.