# Physical and Microbiological Characteristics and Antioxidant Activity of Honey Bee Pollen
## 3 Results  
### Physical Attributes of the Bee Pollen Pellets  
The bee pollen samples analysed in this study had different botanical origins; therefore, a rich variety of pollen colours was observed. Among all analysed bee pollen samples, there were different shades of green and brown, different shades of yellow and orange, and different shades of blue-purple and grey. The values of colour components L * a * b * for monofloral and multifiloral honey bee-collected pollen are summarised in Table S1. Greater colour diversity was found among the samples of monofloral pollen, as they were obtained from eight different plant species, resulting in bee pollen with significant differences (\(p<0.05\)) in colour. A smaller variety of colours was found in the samples of multifiloral pollen, as they mostly consisted of three colours--orange, yellow and green--with the largest percentage attributed to yellow and green pollen. Cluster analysis was used to group and more accurately determine the colour diversity of the bee pollen samples (Figure 1). Cluster analysis allocated bee pollen samples in the following four groups:  
* The first cluster consisted of all multifloral samples studied and two monoflorl (WI and RS) bee pollen samples, in which the pollen was in different hues of yellow, green and slightly orange;
* The second cluster consisted of a dandelion pollen sample (DA), which was dominated by an orange-yellow hue;
* The third cluster consisted of samples of the monoflorl pollen dominated by brown, bluish-grey hue, from AR, RF, FB, and CL;
* In the fourth cluster, there was one sample (PHA), the colour of which was dark purple. Physicochemical parameters of products are essential to ensure their storage and safety for consumers. Therefore, the following parameters were analysed for bee pollen: moisture content, water activity, and pH (Table 1). The moisture content of products is an important quality indicator, which affects the shelf life. The higher the product moisture, the shorter the shelf life, because the increased moisture of the product creates a favourable environment for the development of microorganisms. According to the Regulations of the Cabinet of Ministers of the Republic of Latvia (LR) No. 461 (12 August 2014) and the Guidelines for the primary production of apiculture products, the moisture content of dried pollen must be between 7.0% and 8.0%. The moisture content of the monoflorl be pollen analysed in the current study was from 6.62 \(\pm\) 1.24% to 10.89 \(\pm\) 0.43%, whereas for multifloral pollen, it was 6.67 \(\pm\) 0.22% to 8.61 \(\pm\) 0.96%. Figure 1: Dendrogram showing average linkage between groups of honey bee-collected pollen based on its colour: plants of origin for monoflorl pollen: AR—autumn raspberry, CL—clover; DA—dandelion; FB—fava beans; PHA—phacelia; RF—rye flower; RS—rapeseed; WI—willow; plants of origin for multifloral pollen: MF1—Brocini; MF2—Bene; MF3—Tervete; MF4—Saldus; MF5—Kuldiga. The water activity of the monofloral pollen analysed differed significantly (\(p\) \(<\) 0.05) and ranged from 0.228 \(\pm\) 0.001 to 0.389 \(\pm\) 0.001, while for multifocal pollen, it ranged from 0.187 \(\pm\) 0.002 to 0.324 \(\pm\) 0.001 (Table 1). pH is another bee pollen quality indicator. In the literature, it has been reported that too low pH (below 4.00) can contribute to the activity of unfavourable microorganisms in pollen. The biochemical changes that occur in pollen as soon as it enters the hive can lead to a lowering of the pH. According to the Regulations of the Cabinet of Ministers of the Republic of Latvia (LR) No. 461 (12 August 2014) and the Guidelines for the primary production of apiculture products, the pH of dried pollen must be in the range of 4.3-7.0. The average pH values of the analysed monofloral bee pollen were from 4.738 \(\pm\) 0.006 to 5.827 \(\pm\) 0.013, while for multifocal bee pollen, it was from 4.872 \(\pm\) 0.020 to 5.783 \(\pm\) 0.018, both of which fall within the specified range.