*3.2. Routine Physicochemical Parameters: Moisture Content, Water Activity, pH and Free Aciditiy*

In Table 2 are presented the physicochemical properties of bee pollen samples analyzed. The stability and the shelf life of bee pollen is influenced strongly by the pH and the titratable acidity; these two parameters are a good indicator of the dynamic microbial activity [14]. The bee pollen pH ranged between 3.90 and 5.84 with a mean of 4.60 (*p* < 0.05); the values are in agreement with those reported in the case of pollen from Tuscany, Portugal, Greece and India [8,27,38]. The free acidity ranged between 124.58 and 306.90 meq/kg with a mean of 215.51 meq/kg (*p* < 0.05); the magnitude of free acidity confirmed the acidic nature of the bee pollen. The free acidity of the samples were in agreement with those reported for Colombian bee pollen [39] and Brazilian bee pollen [40]. Moisture content ranged between 2.96% and 11.90% (*p* > 0.05), with an average of 5.00%, which confirms the dry characteristics labeled by the beekeepers on the products; the moisture content was much lower than those reported for bee pollen from Colombia, Italy and Spain [22], but in agreement with the levels determined in Brazilian bee pollen [40]. According to the literature, the moisture content of dry bee pollen should be between 6 to 8% to ensure the bee pollen quality and stability [29]. The water activity is correlated to the stability and shelf life of a product; a high water activity stimulates the growth of microorganisms (e.g., molds, yeasts) and can cause pollen toxicity due to mycotoxins formation [8]. The water activity ranged between 0.17 and 0.55 (*p* < 0.05), with an average of 0.29, in agreement with those reported for bee pollen from Portugal, Spain and Colombia [22,41].


