Μελισσοπαλυνολογική ανάλυση θυμαρίσιου μελιού περιοχών της Ελλάδας

Abstract

The knowledge of greek thyme honey geographical origin is of great importance for its quality assurance, the determination of its particular local characteristics and the protection of both the consumers and the beekeepers. The outdoors experimental procedure of this project was carried out during three successive years (2003, 2004 and 2005) by collecting plant and honey samples from three different areas of Greece: i) Grambousa, Kissamos, Chania, ii) Aghios Nikolaos, Dombrena, and iii) Fanos, Almiros, Volos. Five numbered beehives were set at each experimental station as the source of the honey samples. Moreover, all plants in flower growing up to 2 km from the beehives of each area were collected in two periods during the years 2003 and 2004: the first period was before the anthesis of thyme and the second one was approximately in the middle of the flowering time. Reference slides from all plants in flower were prepared, their pollen grains were photographed at a light microscope and a relevant reference file was created, so as to compare with the pollen grains isolated from the honey samples. From each numbered beehive of all experimental stations, four honey samples were collected per year, and this was repeated for the three years of the study, consequently totaling 180 honey samples. These samples were examined chemically, while a pollen qualitative analysis was also conducted. Moreover, the total number of pollen grains and those of Thymus capitatus were measured separately. For the evaluation of the results the discrimination analysis by SPSS was applied. The palynological analysis included the estimation of the pollen grain dimensions of all plants in flower. In particular, the pollen grains of Thymus capitatus, Satureja thymbra and Origanum vulgare were measured separately in order to reveal any differences in pollen grain characteristics among the areas or periods of collection. Measurements were also carried out in exine sculpture of Thymus capitatus pollen grains by scanning electron microscopy (SEM). The beeculturing plants of each area were found out through the evaluation of the results of honey sample pollen analysis. The analyses of 2003 and 2004 sampling showed that the bees preferred to visit the same plant species, while the weather conditions at the collection areas did not affect the number of plants visited by bees. Measurements of the pollen grain dimensions presented greater variation among different areas and less within the same area. In this project such differences appeared in Thymus capitatus and Satureja thymbra and were related to the climatologic conditions. Regarding the ability to discriminate Thymus capitatus, Satureja thymbra and Origanum vulgare pollen grains on the basis of their size, in the present study this was achieved and it constitutes an important criterion for the accurate determination of the botanical origin of the honey. From the study of pollen grain size and the exine form, it is concluded that Thymus capitatus presents polymorphic pollen grains related with the…