How soil type (gypsum or limestone) influences the properties and composition of thyme honey

BACKGROUND AND AIMS The objective of this work was to determine the influence of the soil substrate on the characteristics and properties of a specific type of honey. As such, we analysed the features of a typical single-flower honey, thyme honey, produced in a specific Mediterranean region. Thymus is a genus of aromatic perennial plants that are native to Europe, North Africa and Asia. METHODS A total of 70 honey samples from hives situated on limestone (38 samples) or gypsum soils (32 samples) were studied. The physical and chemical properties of each samples were analyzed using standard assays. RESULTS Within the same geographical area and despite a similar thyme pollen content, we observed variation in the physicochemical, antioxidant and sensorial characteristics of monofloral honeys. The quantification of certain physicochemical parameters of the honey indicated these features were influenced by the soil type. Indeed, the soil type of the hives' settlement area, limestone or gypsum, influences the conductivity, antioxidant capacity, colour and floristic composition. CONCLUSIONS The present work demonstrates that soil type (gypsum or limestone) influences the characteristics of honey, potentially providing added market value to these products.