# Physical and Microbiological Characteristics and Antioxidant Activity of Honey Bee Pollen
## 4 Discussion  
Analysis of the bee pollen samples' colours (Supplementary Table S1) and their diversity indicated that the predominant pollen samples were yellow or orange, so it was very difficult to determine the exact botanical origin of pollen by colour alone. Pollen from different plant species can be very similar or even identical in colour. This was also confirmed by some of the pollen analysed in the current study, such as bee pollen from willow (WI) and rapeseed (RS), as well as samples of multifocal pollen with a very similar colour profile. For this reason, further examination under a microscope is required for accurate identification of the plant species from which the pollen is collected, as described by [PERSON] et al. [23]. According to the information presented in a study by [24], there are plants in nature whose pollen colour is particularly specific, and their origin can be easily determined without more in-depth research. These types of plants include phacelia, the bee pollen of which is dark blue; the clover, the pollen of which is dark brown; raspberry, having grey pollen; lastly, fava beans, the bee pollen of which is recognizable by its green hue. Such colour relationships were precisely the ones also found in our study. The highest moisture content was found in PHA (10.89 \(\pm\) 0.44%), AR (9.99 \(\pm\) 0.43%), and RF (9.93 \(\pm\) 0.71%) bee pollen, which could be explained by high relative air humidity during the bee pollen collection period and drying process, which has been identified in the literature as one of the main determinants of moisture content in pollen. Moisture content (up to 8.0%), which complies with Regulation No. 461 of the Latvian Cabinet of Ministers on optimal pollen moisture, was found in clover (CL), dandelion (DA), rapeseed (RS), and willow (WI) pollen. A comparison of the results of other studies revealed that the optimal moisture content of dried bee pollen varied from country to country--up to 8% in Argentina, 10% in Bulgaria, and 6% in Switzerland and Poland [25]. Swiss scientists have found that if the moisture content of dried pollen is higher than 6%, it can negatively affect the quality of the pollen--mould can form, which can result in an unpleasant taste and aroma for pollen. Studies by [26], based on changes in moisture content depending on the duration of pollen storage, revealed that proper packaging and storage of pollen is a key factor, and if this process is carried out correctly, storage time does not contribute to moisture content changes in pollen. After evaluating the moisture content in the analysed multifloral bee pollen, it was found that there were significant differences between the moisture content of the analysed samples (\(p<0.05\)), although they did not exceed the optimal limits specified in the Regulations of the Cabinet of Ministers of the Republic of Latvia. The highest moisture content (8.61 \(\pm\) 0.96%) was found in Tervete (MF3) pollen, while the lowest moisture content (6.67 \(\pm\) 0.22%) was found in Bene (MF2) pollen. Among all analysed multifloral pollen samples, Tervete (MF3) pollen was found to have a slightly higher moisture content than that specified in the Regulations of the Cabinet of Ministers of the Republic of Latvia (LR) No. 461 (12 August 2014) and in the Guidelines for Primary Production of Beekeeping Products (7-8%), but this was within the measurement error. The differences between all of the analysed moisture content indicators of bee pollen samples can be explained by the fact that they were collected in different parts of Latvia, with different relative humidity during the harvest period; in addition, drying methods and packaging materials (polyethylene (PE) pouches vs. glass containers) also differed. Water activity (a\({}_{\text{w}}\)), along with moisture content, is one of the factors that characterise and affect the quality of the pollen.