Characterisation of Spanish thyme honeys by their physicochemical characteristics and mineral contents

The qualities of 25 thyme honey samples from Spain were evaluated. Eight common physicochemical parameters were analysed, namely water content, pH, acidity (free, lactonic and total), sugar content, ash, electrical conductivity and mineral composition, including potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), phosphorus (P) and sulphur (S). Most samples showed proper maturity, considering the low water content. The total acidity (below 50 meq/kg) indicated the absence of undesirable fermentation; also the mean pH, around 4.2, is usual in this kind of honey. The values for ash and electrical conductivity were medium (0.32% and 395 μS cm−1, respectively), typical of dark amber honeys. Within the mineral content, potassium was quantitatively the most important mineral, having an average content of 679 ppm; sodium and calcium were present in moderate amounts in the honeys and accounted for 27% and 13% of the minerals, respectively.