Mineral Composition and Heavy Metal Contents of Chestnut Honey Collected From Kastamonu Region

Abstract

Chestnut honey, which is known for its apitherapic properties besides its nutritional attributes, is one of the main groups of monofloral honey types. Kastamonu is the most important province because where constitutes two-thirds of the chestnut forest flora of the Black Sea region. Kastamonu Chestnut Honey, produced in apiaries within the chestnut forests, has been registered as a geographical indication and designation of origin. The nutritional value of honey is related to its nutritional and chemical content. Kastamonu chestnut forests have a different distribution with their scattered structure from the coastline to 1000-1200 meters altitude. Therefore, this study was planned with the prediction that chestnut honey produced in different districts has a different composition. The aim of the study is to contribute to official regulations regarding the product, product standardization, and national branding studies by determining mineral and heavy metal contents based on the region where the chestnut honey is produced. As a result of the study, the main concentrations of the elements in the chestnut honey samples were affected by the geographical location, because the apiaries where honey samples were collected in chestnut forests in Kastamonu districts had different altitudes, climates and soil properties, and different secondary flora. The most abundant elements in the samples were potassium (1410.0-6581.5 ppm) sodium (0-204.4 ppm), calcium (125.3-287.5 ppm), and magnesium (24.73-61.88 ppm). Iron (1.32-9.54 ppm), zinc (1.34-20.84 ppm), and manganese (1.39-18.69 ppm) were also found in moderate and others in trace levels. Because manganese is found at moderate levels in all chestnut honey samples and it is found at higher levels than other honey types, it can be recommended that Mn, as fingerprints to detect imitation and adulteration of chestnut honey. While Cd, a heavy metal, was found in only one sample, Ni was not detected in any sample. Whereas Pb concentration varied between 1.84 ppm and 3.38 ppm for the samples, the contents of Al concentrations were quite high (2.94-13.94 ppm). Because there wasn't a maximum limit for heavy metal contents of honey types in the Turkish Food Codex Contaminants Regulation, no evaluation could have been made regarding the suitability of these heavy metal contents. It is thought that heavy metal contamination limits in honey types should be included in the regulations and especially secondary sources such as metallic containers used for storage during handling processes and harvesting of honey for heavy metal contamination should be reviewed.