## 3 Results
### PCA and PLS Regression Analyses  
PCA was performed on volatile and sensory data from control, heat-treated, and PEF-treated orange juices (Figure 2). The first two principal components (PCs) accounted for 89.02% of the total variance. In the score plot, the Thermal-2 orange juice sample was located on the left side of PC1, whereas the untreated and PEF-treated orange juice samples were located on the right side of PC1. Thermal-2 orange juice was strongly correlated with \(\beta\)-myrcene (turpentine, mint, spice), terpinolene (unpleasant, citrus), \(\beta\)-terpineol (woody, pungent, earthy), and \(\beta\)-fenchyl alcohol (camphor odor). However, untreated, PEF-treated, and Thermal-1-treated juice samples were positively correlated with ethyl butyrate (sweet, fruity), \(\alpha\)-pinene (\(\alpha\)-pinene), dl-limonene (lemon, citrus-like), and \(\beta\)-cubebene (unpleasant, citrusy, chemical). This is consistent with the volatile composition and explains why the Thermal-2-treated orange juice differed greatly from untreated juice. All significant sensory attributes (\(p<0.05\)) were included to produce the PCA plots shown in Figure 2B. The first two PCs explained 97.56% of the total variance. On the score plot, only Thermal-2-treated orange juice was located on the right side of PC1, and was correlated with bitter and cooked sensory attributes. However, untreated, PEF-treated, and Thermal-1-treated orange juice were located on the left side of PC1 and were correlated with sour and fresh sensory attributes. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sensory Attributes** & **Untreated** & **Thermal-1** & **Thermal-2** & **PEF-1** & **PEF-2** \\ \hline \multicolumn{5}{c}{Aroma} \\ \hline Fresh orange aroma & \(6.1\pm 1.9\) \({}^{\text{a}}\) & \(5.7\pm 1.4\) \({}^{\text{a}}\) & \(3.4\pm 2.2\) \({}^{\text{b}}\) & \(6.8\pm 1.2\) \({}^{\text{a}}\) & \(5.4\pm 1.3\) \({}^{\text{a}}\) \\ Cooked orange aroma & \(4.4\pm 1.6\)\({}^{\text{b}}\) & \(3.5\pm 0.8\)\({}^{\text{b}}\) & \(7.0\pm 1.2\) \({}^{\text{a}}\) & \(3.7\pm 1.2\)\({}^{\text{b}}\) & \(3.6\pm 1.1\)\({}^{\text{b}}\) \\ \hline \multicolumn{5}{c}{Taste} \\ \hline \hline Sour & \(5.5\pm 2.0\)\({}^{\text{ab}}\) & \(5.5\pm 1.2\)\({}^{\text{ab}}\) & \(4.1\pm 2.0\)\({}^{\text{b}}\) & \(6.9\pm 1.3\)\({}^{\text{a}}\) & \(5.9\pm 1.0\)\({}^{\text{a}}\) \\ Sweet & \(4.8\pm 2.0\)\({}^{\text{a}}\) & \(5.4\pm 1.4\)\({}^{\text{a}}\) & \(4.3\pm 1.8\)\({}^{\text{a}}\) & \(4.8\pm 1.7\)\({}^{\text{a}}\) & \(5.6\pm 2.0\)\({}^{\text{a}}\) \\ Bitter & \(4.2\pm 1.8\)\({}^{\text{b}}\) & \(4.1\pm 1.4\)\({}^{\text{b}}\) & \(6.5\pm 1.3\)\({}^{\text{a}}\) & \(4.3\pm 1.3\)\({}^{\text{b}}\) & \(4.3\pm 1.6\)\({}^{\text{b}}\) \\ Vegetable & \(4.6\pm 2.2\)\({}^{\text{a}}\) & \(4.9\pm 1.9\)\({}^{\text{a}}\) & \(5.9\pm 2.0\)\({}^{\text{a}}\) & \(4.6\pm 1.8\)\({}^{\text{a}}\) & \(4.5\pm 1.8\)\({}^{\text{a}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Effect of PEF and thermal treatments on sensorial properties of squeezed orange juice PLS regression analyses were performed on the sensory attribute and volatile data (Figure 3). Latent vectors 1 and 2 (LV1 and LV2) explained 87.6% of the variation. Along LV1, there was a clear separation among the samples due to the treatments. The PEF-treated and weakly heated (i.e., Thermal-1) samples were more similar to the untreated sample on LV1 than the Thermal-2 orange juice. Untreated and PEF-treated samples were positively correlated with sour and fresh sensory attributes, which were associated with \(\alpha\)-pinene (woody, pine, terpenic, herbal odor), dl-limonene (lemon, citrus-like, odor), \(\beta\)-cubebe (citrus, fruity odor), ethyl butyrate (sweet, fruity odor), and \(\beta\)-myrcene (green, metallic, balsam odor).