## 3 Results and Discussion
### Chemical Composition
#### 3.1.3 Chemical Composition of Propolis  
Propolis is the result of harvesting and processing by bees of resinous substances from some plants, to which they add glandular secretions, wax, and residues from the digestion of pollen. In the hive, bees use propolis for sealing and sanitizing the nest and secondarily for polishing the walls of the hive and the cells, covering killed pests. Even though the chemical composition varies considerably, being correlated with the geographical area and the plants used by the bees to produce it, propolis has similar properties, including antibacterial, antifungal, antiparasitic, antiviral, anti-inflammatory, and antioxidant activities [46; 47; 48]. Raw propolis usually contains 50% vegetable resins, 30% wax, 10% essential and aromatic oils, 5% pollen, and 5% other organic substances [16]. The raw propolis samples that we analyzed had a moisture content of 0.35-0.66%, the maximum value being recorded in the commercial samples, with statistically significant differences (\(p<0.05\)) compared with the propolis from our own apiary (Table 5). We observed that the acidity of the commercial samples was 15.87 mg/g higher compared with the samples harvested from own apiary (5.95 mg/g) with statistically significant differences (\(p<0.05\)), and a similar situation was observed for impurities (Table 5). The evaluation of macroelements revealed calcium as the main element at 840.40 mg, with significant differences between the sources of origin (\(p<0.05\)), followed by magnesium 144.24 mg, phosphorus 132.00 mg, sodium 103.29 mg, and potassium 97.34 mg. The best represented microelement was iron 54.58 mg, followed by zinc 15.85 mg, manganese 4.91 mg, and copper 3.13 mg, with statistically insignificant differences between propolis \begin{table}
\begin{tabular}{c c c c} \hline  & \multicolumn{2}{c}{**Fresh Royal Jelly**} & **Lyophilized Royal Jelly**} \\  & **Own Apiary** & **Market** & \\  & **Mean \(\pm\) SD** & **Mean \(\pm\) SD** & **Mean \(\pm\) SD** \\ \hline \multicolumn{4}{c}{Macroelements} \\ \hline Na & 182.67 \(\pm\) 8.457 \({}^{\rm a}\) & 187.53 \(\pm\) 8.761 \({}^{\rm a}\) & 179.11 \(\pm\) 4.992 \({}^{\rm A}\) \\ \hline Ca & 200.79 \(\pm\) 1.994 \({}^{\rm a}\) & 382.12 \(\pm\) 30.716 \({}^{\rm b}\) & 1218.42 \(\pm\) 1101.62 \({}^{\rm A}\) \\ \hline K & 1182.42 \(\pm\) 414.80 \({}^{\rm a}\) & 1659.43 \(\pm\) 509.61 \({}^{\rm a}\) & 2553.17 \(\pm\) 878.77 \({}^{\rm A}\) \\ \hline Mg & 365.77 \(\pm\) 75.038 \({}^{\rm a}\) & 423.32 \(\pm\) 19.367 \({}^{\rm a}\) & 782.40 \(\pm\) 109.17 \({}^{\rm B}\) \\ \hline P & 1648.38 \(\pm\) 343.83 \({}^{\rm a}\) & 1125.75 \(\pm\) 191.62 \({}^{\rm a}\) & 2799.00 \(\pm\) 890.95 \({}^{\rm A}\) \\ \hline \multicolumn{4}{c}{Microelements} \\ \hline Fe & 17.87 \(\pm\) 7.219 \({}^{\rm a}\) & 19.43 \(\pm\) 7.353 \({}^{\rm a}\) & 36.34 \(\pm\) 6.243 \({}^{\rm A}\) \\ \hline Mn & 4.20 \(\pm\) 0.636 \({}^{\rm a}\) & 5.32 \(\pm\) 1.965 \({}^{\rm a}\) & 4.91 \(\pm\) 0.155 \({}^{\rm A}\) \\ \hline Cu & 6.26 \(\pm\) 1.449 \({}^{\rm a}\) & 7.12 \(\pm\) 0.820 \({}^{\rm a}\) & 15.78 \(\pm\) 0.721 \({}^{\rm B}\) \\ \hline Zn & 19.71 \(\pm\) 5.769 \({}^{\rm a}\) & 21.95 \(\pm\) 3.075 \({}^{\rm a}\) & 51.07 \(\pm\) 4.617 \({}^{\rm B}\) \\ \hline Cr & 1.03 \(\pm\) 0.332 \({}^{\rm a}\) & 2.95 \(\pm\) 4.164 \({}^{\rm a}\) & 2.68 \(\pm\) 0.784 \({}^{\rm A}\) \\ \hline \multicolumn{4}{c}{Contaminants} \\ \hline Ni & Undetectable & undetectable & Undetectable \\ \hline Cd & 0.70 \(\pm\) 0.169 \({}^{\rm a}\) & 1.51 \(\pm\) 0.106 \({}^{\rm b}\) & 1.29 \(\pm\) 0.247 \({}^{\rm A}\) \\ \hline Pb & Undetectable & undetectable & Undetectable \\ \hline \end{tabular} Results are expressed as the two-determination mean \(\pm\) standard deviation (SD). Different letters indicate statistically significant differences between samples in a row (\(p<0.05\)) according to the Tukey test.  
\end{table} 
Table 4: _Cont._sources (Table 5). Chromium was not detected in the raw propolis samples.