# Can Bioelectrical Impedance Analysis (BIA) Be Used to Predict Pig's Meat Quality In Vivo?
## 3 Results and Discussion
These authors showed in a PCA analysis also that both principal components that explained about 51% of total variability and similar traits (pH, drip loss, color values) were related with the bioimpedance parameter but were measured in meat after slaughter. The second component was strongly and negatively related to pH1, pH24, and color L* value, as well as positively with color a* value (Table 3, Figure 1). Then, the K-means cluster analysis was used to check whether the bioimpedance measurements in combination with the meat quality traits allowed for the separation of subgroups with different meat quality  
Figure 1: Principal components analysis results—location of individual traits based on their relationship with each other and principal components. Rz = resistance (ohm); Xc = reactance (ohm); HCW = hot carcass weight (kg); DL-drip loss; PG, glycolytic potential; IMF, intramuscular fat. in the studied group of pigs. The meat quality traits with bioimpedance measurements were used as focusing criteria. The results showed that three groups of pigs with various meat quality parameters and bioimpedance measurements were obtained as the effect of cluster analysis (Table 4 and Figure 2). The analysis of variance showed that the obtained cluster group differed significantly for the Rz bioimpedance trait, pH\({}_{24}\), PG, and b* color values (Table 4). The results showed that groups from cluster 1 and 2 differed significantly between traits Rz, pH\({}_{24}\), PG, and color b* values (Table 4 and Figure 2), while the group from cluster 3 did not differ significantly from the other two groups. The meat of fatteners from cluster 1 appeared with higher R\({}_{2}\) resistance with a better value of ultimate pH, lower glycolytic potential, and lower color b* value (Table 4). The meat of fatteners from cluster 2 was characterized by lower ultimate pH, higher GP, and color b* value, while the meat from cluster 3 was intermediate between both previous in meat quality traits (pH\({}_{24}\), GP, and color b* value) and completely different from both in terms of resistance (R\({}_{2}\)). Regarding the meat quality traits, the obtained relationship between the characteristics with regard to pH, GP, and color were consistent with the results of the studies by Hamilton et al. (2013), Nani-Costa et al. (2013), and Copenhagenfer et al. (2014). Cluster analysis showed that bioimpedance measurements combined with meat quality traits make it possible to distinguish groups with different quality parameters. However, the relationships between them are complex and still require analysis. Suliga et al. (2015), in \begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{3}{c}{**Clusters**} \\ \cline{2-4}  & **Cluster 1** & **Cluster 2** & **Cluster 3** \\ \hline Rz/Xc/HCW & 11.05 & 8.66 & 7.80 \\ Rz (\(\Omega\)) & 197.00 \({}^{\text{a}}\) & 170.33 \({}^{\text{b}}\) & 117.50 \({}^{\text{c}}\) \\ Xc (\(\Omega\)) & 22.00 & 25.33 & 20.00 \\ Rz/Xc & 9.08 & 7.45 & 6.21 \\ pH\({}_{1}\) & 6.48 & 6.52 & 6.44 \\ pH\({}_{24}\) & 5.66 \({}^{\text{a}}\) & 5.58 \({}^{\text{b}}\) & 5.65 \({}^{\text{a}}\) \\ PG (mmol/L) & 115.13 \({}^{\text{a}}\) & 140.98 \({}^{\text{b}}\) & 127.78 \({}^{\text{ab}}\) \\ Color L* & 55.15 & 55.25 & 54.81 \\ Color a* & 15.64 & 16.48 & 16.14 \\ Color b* & 8.69 \({}^{\text{a}}\) & 9.71 \({}^{\text{b}}\) & 9.39 \({}^{\text{ab}}\) \\ Natural drip loos (\%) & 2.59 & 4.02 & 4.19 \\ Intramuscular fat (\%) & 2.48 & 1.41 & 1.45 \\ \hline \hline \end{tabular} Explanation: a,b—means with different letters differs significantly at \(p<0.05\); Rz = resistance (ohm), Xc = reactance (ohm), HCW = hot carcass weight (kg).  
\end{table} 
Table 4: Mean values for clusters obtained from the cluster analysis using the K-means method.