An overview of the challenges when analysing pollen for monofloral honey classification

The complexity of the pollen analysis, even for accredited laboratories, and the absence of standardized guidelines for a routine method to determine the monoflorality of a honey is a challenge. To expose the reality of this situation, the aim of this work is to discuss how the information and the quantification of the honey pollen content results are presented, considering the reports provided by four of these laboratories. Noticeable differences in how the data is presented is observed; not only in the number of types of pollens (main and accompanying) which percentage is reported but also for the criteria followed in naming the same pollen, applying different taxonomic levels (family, genus, type, specie, etc.). Although there is one common consensus by all laboratories based on discarding the pollens from non-melliferous plants, in general the discrepancies observed are important. The problem is more evident when there is a presence of over-represented pollen and the target pollen is under-represented as is the case of Citrus. Thus, the simultaneous presence of under-represented and over-represented grains of pollen may frequently lead to misleading results. The lack of standardization in pollen analysis to be applied equally by all laboratories significantly contributes to the discrepancies. Only by having a common criterion to interpret the pollen spectrum and, obviously, ensuring the adequate experience of the analyst and the knowledge of the related flora is when the results can be considered reliable.