## 3 Results and Discussion
### Analysis of Adulterated Milk and the Influence of Temperature
\begin{table}
\begin{tabular}{l c c c c c c c c c} \hline  & \multicolumn{6}{c}{**Percentage of Water in Milk**} \\  & \multicolumn{2}{c}{**0.0\%**} & \multicolumn{2}{c}{25\%} & \multicolumn{2}{c}{**50\%**} & \multicolumn{2}{c}{**75\%**} & \multicolumn{2}{c}{**97.9\%**} \\ \hline \(f\) (Hz) & \(|Z|(\Omega)\) & \(\theta\) & \(|Z|(\Omega)\) & \(\theta\) & \(|Z|(\Omega)\) & \(\theta\) & \(|Z|(\Omega)\) & \(\theta\) & \(|Z|(\Omega)\) & \(\theta\) \\ \hline \(10^{1}\) & \(197.3\pm 2.7\) & \(-19.3\pm 0.6\) & \(230.0\pm 4.8\) & \(-19.2\pm 0.8\) & \(290.5\pm 3.8\) & \(-17.8\pm 0.3\) & \(462.9\pm 17.4\) & \(-16.0\pm 2.0\) & \(2400.2\pm 35.4\) & \(-8.2\pm 0.8\) \\ \(10^{2}\) & \(170.3\pm 2.3\) & \(-15.5\pm 1.3\) & \(193.2\pm 3.4\) & \(-15.0\pm 0.0\) & \(256.1\pm 9.0\) & \(-13.8\pm 0.3\) & \(417.7\pm 29.2\) & \(-11.7\pm 1.0\) & \(2244.5\pm 37.8\) & \(-4.3\pm 0.6\) \\ \(10^{3}\) & \(149.0\pm 0.7\) & \(-0.6\pm 2.2\) & \(175.2\pm 1.7\) & \(-6.7\pm 0.3\) & \(231.7\pm 1.3\) & \(-6.8\pm 1.6\) & \(387.8\pm 1.25\) & \(-4.3\pm 1.5\) & \(2162.5\pm 21.7\) & \(-3.0\pm 1.0\) \\ \(10^{4}\) & \(135.6\pm 1.6\) & \(-5.7\pm 0.6\) & \(162.0\pm 1.6\) & \(-6.0\pm 0.5\) & \(216.5\pm 3.5\) & \(-4.5\pm 0.9\) & \(363.5\pm 7.6\) & \(-3.4\pm 0.3\) & \(2011.6\pm 25.2\) & \(-2.7\pm 0.6\) \\ \(10^{5}\) & \(121.8\pm 0.0\) & \(-4.0\pm 0.5\) & \(145.3\pm 1.0\) & \(-3.8\pm 0.3\) & \(197.8\pm 0.7\) & \(-3.2\pm 0.8\) & \(341.3\pm 8.3\) & \(-2.7\pm 0.8\) & \(2011.5\pm 17.4\) & \(-5.7\pm 0.3\) \\ \(10^{6}\) & \(112.3\pm 0.9\) & \(1.3\pm 0.3\) & \(134.8\pm 1.0\) & \(0.8\pm 0.3\) & \(184.3\pm 1.6\) & \(0.5\pm 0.5\) & \(318.1\pm 10.2\) & \(-1.8\pm 0.8\) & \(1541.8\pm 25.2\) & \(-32.0\pm 1.0\) \\ \(2.3\times 10^{6}\) & \(110.0\pm 0.5\) & \(7.5\pm 0.5\) & \(132.8\pm 0.1\) & \(6.8\pm 0.3\) & \(181.1\pm 0.5\) & \(5.2\pm 0.3\) & \(308.7\pm 5.8\) & \(-0.3\pm 0.8\) & \(970.1\pm 9.2\) & \(-45.2\pm 0.3\) \\ \hline \end{tabular}
\end{table} 
Table 2: Impedance magnitude and phase values measured at 28 \({}^{\circ}\)C for the different dilutions with distilled water in milk (% \(V/V\)) and unadulterated milk (0%). Figure 9: Adulterated milk impedance measurements at 28 \({}^{\circ}\)C. Frequency response is shown in (**A**,**B**). The effect of water dilution on the complex impedance is emphasised in (**C**,**D**). For each frequency level and percentage of water in milk, the complex impedance was measured three times according to the proposed methodology. The standard deviations shown in Tables 1-3 reflect the uncertainty inherent in the experimental results. There are many causes of variability in experimental data. Fluctuations in the amplitude of the excitation signal lead to variability in the excitation current, and consequently, in the impedance calculations. Additionally, all voltage measurements are performed with an oscilloscope, and its accuracy depends on how the data are acquired. Another source of uncertainty is the electrode impedance, which has not been evaluated in this work. Finally, there are variations in the sample composition itself and its volume. The experiment was repeated with milk from different production batches. All these sources of uncertainty propagate to the impedance measurement calculations. The results analysis shows that bioimpedance values are inversely proportional to the temperature; i.e., the higher the temperature of the analysed sample, the lower the  
Figure 10: Adulterated milk impedance measurements at 37 \({}^{\circ}\)C. Frequency response is shown in (**A**,**B**). The effect of water dilution on the complex impedance is emphasised in (**C**,**D**).