Investigating the effect of postharvest conditions on the microbial quality and physicochemical characteristics of bee pollen

Considering the scarcity of information on postharvest management of bee pollen, especially its fresh form, this study aims to investigate the effect of storage conditions and duration on the microbial load of fresh and dried pollen, while also considering changes in physicochemical parameters. Specifically, microbiological analyses were applied to record the growth of Mesophilic Total Viable Counts (MTVC), Yeasts & Moulds (Y&M), Enterobacteriaceae (ENT), Lactic Acid Bacteria (LAB), and Escherichia coli. The results showed that fresh pollen can be stored in the freezer (-18 °C) for one year, without exceeding the legislative limits for the studied pathogens, as after storing for 12 months, the mean counts of MTVC, Y&M, ENT, and LAB were 3.93, 4.04, 1.71, and 2.82 log cfu/g, respectively, whereas moisture, protein and lipid content, fatty acid composition, and colour remained unchanged. When fresh pollen was stored at 4 °C, over a six-month period, the MTVC & ENT counts were out of limits, and changes were observed in colour, total lipid content (32.18% decrease), and fatty acid composition (31.68% for C18:2 and 21.56% for C18:3 reduction, 31.5% increase for C18:0). Finally, storing fresh pollen at 25 °C is deemed insufficient for maintaining quality characteristics. Dried pollen demonstrated better results, compared to fresh pollen, maintaining values of microbial load within legislative limits at all storage temperatures, thus making long-term storage easier. The data gathered during this study may form the basis for a guide including proper beekeeping practices and postharvest bee pollen treatment and management, contributing to the optimization of pollen production.