Characterization of anzer honey using molecular methods

One of the natural foods most commonly subjected to fraud is honey. Analyzing honey using a method that is simpler, more specific, and less time-consuming than melissopalynology, may make it possible to more easily determine both its botanical and geographical origin whilst preventing fraud. In recent years, next-generation sequencing (NGS) analysis has been proposed as an alternative approach for identifying pollen grains. In the present study, three honey samples produced in Anzer (Ballıköy) in the Rize province were analyzed using nrDNA ITS (ITS1 and ITS2) obtained from the honey metagenome for the first time and evaluated alongside melissopalynological and palynological data. First, pollen isolation and identification were conducted for the melissopalynological study from the three honey samples examined, and total DNA isolations were performed for the NGS analysis, with their quality determined by spectrophotometric methods. Then, ITS data belonging to the metagenome isolated from each honey sample were sequenced using the Illumina Miseq, one of the next-generation sequencing (NGS) techniques and compared with the reference library prepared within the scope of the thesis. A total of 310 745 filtered paired-end reads for ITS1 and 39 835 filtered paired-end reads for ITS2 were obtained from the three honey samples through NGS analysis. In total, 233 655 (75.2%) of the filtered ITS1 reads and 27 230 (68.4%) of the ITS2 reads matched at least to the family level, and in some cases to the genus or species level, with the database in the specially prepared reference library. NGS analysis identified a total of 27 families and 54 taxa in the honey samples, while melissopalynology identified 19 families and 34 plant taxa. NGS analysis detected 63% more plant taxa than the melissopalynological method across all honey samples. Moreover, when comparing the data obtained from melissopalynology with the NGS data, a significant number of common plant families and genera were identified, with NGS providing significantly higher resolution at the species level. Although there were some differences in the plants identified by the two techniques, the dominant floral components identified showed high similarity.