Comparison of Physicochemical Properties of Bee Pollen with Other Bee Products

Abstract

The aim of this study was to compare the physichochemical composition of various bee products, namely, bee pollen, beebread, propolis, honey, and royal jelly. The samples (37 out of 53) were collected in Lithuania, several samples from other Europe countries (Italy, Denmark, Sweden, Slovakia, Poland, Spain, Republic of Malta, The Netherlands, Latvia, Ukraine) were used for comparison. Various quantities, such as pH, electrical conductivity, oxidation-reduction potential, NaCl content, refraction index, Brix value, total phenolic compound content, total flavonoid content and antiradical activity were measured. Together with the mentioned, the content of micro- and macroelements (As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Se, Sr, V and Zn), ultraviolet-visible spectroscopy absorption spectra were analysed. To our knowledge, the literature data about comprehensive comparison of various characteristics of bee products are scarce. Also, to the best of our knowledge, this is the first study revealing mineral content in Lithuanian bee pollen, beebread and royal jelly. The study exposed that bee pollen not only showed the highest values of pH, electrical conductivity and content of soluble solids, but also distinguished from the other samples by the highest flavonoid content (up to 48.3 mg/10 g), the absence of Cr, the presence of Co (0.011–0.100 mg/kg) and Sr (0.73–5.37 mg/kg) and the highest content of Ca (997–2455 mg/kg) and Mg (644–1004 mg/kg). Hierarchical clustering analysis was applied to group the tested samples according to the physicochemical analysis results and mineral content. The clustering analysis revealed that bee pollen formed separate group with the highest distance from the other samples in both cases.

Post grafting time significantly influences royal jelly yield and content of macro and trace elements

“…Notably however, the Ca, Na, Mg, Fe, Zn, and Cu concentrations were higher than the ranges in RJ produced in China [5], Lithuania [34], and Bingol [9], and the concentrations of Ca, Fe, and Mn were higher than the concentrations in RJ produced in Jordan [20]. Conversely, K concentrations in the RJ samples in the current study were lower than those in RJ produced in China [5], Lithuania [34], and Bingol [9].…”

“…Generally, the macro elements could be arranged in a descending order: P > Mg > Ca > K > Na, and they constituted 39.8%, 34.6%, 15.2%, 8.0%, and 1.7% of the total elements quantified. Wang et al [5] reported that K, Mg, Ca, Na, and Fe were the most abundant elements in RJ produced in China, Adaškevičiũtė et al [34] reported that K, P, Mg, Na, and Ca were the…”

“…Generally, the macro elements could be arranged in a descending order: P > Mg > Ca > K > Na, and they constituted 39.8%, 34.6%, 15.2%, 8.0%, and 1.7% of the total elements quantified. Wang et al [ 5 ] reported that K, Mg, Ca, Na, and Fe were the most abundant elements in RJ produced in China, Adaškevičiũtė et al [ 34 ] reported that K, P, Mg, Na, and Ca were the most abundant elements in RJ from Lithuania, and Bengü et al [ 9 ] reported that K, Mn, Mg, Ca, and Na were the most abundant elements in RJ from Bingol. Variations in macro element concentrations in RJ produced in different regions are reportedly affected by floral resources, differences in climate and geography [ 31 , 39 ], and the elements in pollen consumed by nurse worker bees [ 40 , 41 ].…”

“…Fe, Zn, Cu, and Mn constituted less than 0.8% of the total estimated elements in RJ harvested at different times after grafting. Relatively similar Fe, Zn, and Cu concentrations were reportedly detected in RJ produced in China [5], Lithuania [34], and Bingol [9]. Conversely, a high concentration of Mn was reportedly detected in RJ from Bingol [9].…”

“…The nutritional and therapeutic characteristics of RJ have led to its inclusion in an increasing number of food products [7,9,18,[29][30][31][32][33][34]. Royal jelly is commercially harvested at the end of the 4 th day of queen larval age [2,8,35], but there are few reports on the element content of RJ harvested before this time.…”