## 3 Results
The Pearson table for critical values for correlation was consulted, and variables with normalized loading values greater than 0.7 and lower than \(-\)0.7 were considered significant for the model (\(p<0.05\)). Monoacylglycerolycerols, 1,2-propanediol, and fumaric acid are the metabolites positively correlated with PC1 meaning that they are more abundant in carrots harvested in September. The levels of tryptophan, valine, isoleucine, leucine, threonine, glutamine, asparagine, inosine triphosphate,  
Figure 3: PCA scores of the purple carrot. Carrots harvested in September are evidenced in blue, October in red, and November in green. NAD, quinic acid, aspartic acid, acetic acid, histidine, phenylalanine, alanine, and caffeic acid are higher in carrots harvested at later months. In Table 1, only the concentrations of the metabolites identified as important for the separation of carrot harvest time according to PCA analysis are reported. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Metabolite**} & \multicolumn{3}{c}{**Amount (\(\mu\)mol/g)**} \\  & **September** & **October** & **November** \\ \hline Leucine & 0.26 \(\pm\) 0.03 & 0.63 \(\pm\) 0.06 \(\lx@sectionsign\) * & 1.93 \(\pm\) 0.14 \(\dagger\) ** \\ Isoleucine & 0.08 \(\pm\) 0.02 & 0.25 \(\pm\) 0.03 \(\lx@sectionsign\) * & 0.93 \(\pm\) 0.05, \(\dagger\) ** \\ Valine & 0.12 \(\pm\) 0.01 & 0.37 \(\pm\) 0.03 \(\lx@sectionsign\) * & 1.15 \(\pm\) 0.07 \(\dagger\) ** \\
1,2-propanediol & 0.82 \(\pm\) 0.08 & 0.38 \(\pm\) 0.03 \(\lx@sectionsign\) ** & 0.25 \(\pm\) 0.03 \\ Threonine & 0.07 \(\pm\) 0.01 & 0.14 \(\pm\) 0.01 \(\lx@sectionsign\) * & 0.31 \(\pm\) 0.02 \(\dagger\) * \\ Alanine & 0.38 \(\pm\) 0.05 & 1.11 \(\pm\) 0.19 \(\lx@sectionsign\) ** & 1.19 \(\pm\) 0.11 \\ Quinic acid & 1.04 \(\pm\) 0.11 & 1.01 \(\pm\) 0.05 & 1.52 \(\pm\) 0.05 \\ Acetic acid & 0.24 \(\pm\) 0.02 & 0.26 \(\pm\) 0.02 & 0.65 \(\pm\) 0.12 \(\dagger\) * \\ Glutamine & 2.45 \(\pm\) 0.55 & 5.06 \(\pm\) 0.91 & 11.65 \(\pm\) 0.64 \(\dagger\) * \\ Aspartic acid & 0.39 \(\pm\) 0.07 & 0.46 \(\pm\) 0.13 & 0.94 \(\pm\) 0.11 \(\dagger\) * \\ Asparagine & 0.61 \(\pm\) 0.09 & 1.13 \(\pm\) 0.16 & 2.08 \(\pm\) 0.11 \\ ITP & 0.021 \(\pm\) 0.002 & 0.015 \(\pm\) 0.003 & 0.06 \(\pm\) 0.01 \(\dagger\) * \\ Caffeic acid & 0.26 \(\pm\) 0.01 & 0.18 \(\pm\) 0.04 & 0.49 \(\pm\) 0.07 \(\dagger\) ** \\ Fumaric acid & 0.44 \(\pm\) 0.02 & 0.40 \(\pm\) 0.03 & 0.30 \(\pm\) 0.03 \\ Phenylalanine & 0.021 \(\pm\) 0.003 & 0.07 \(\pm\) 0.01 & 0.09 \(\pm\) 0.01 \\ Tryptophan & 0.04 \(\pm\) 0.01 & 0.11 \(\pm\) 0.03 \(\lx@sectionsign\) ** & 0.38 \(\pm\) 0.03 \(\dagger\) ** \\ Histidine & 0.21 \(\pm\) 0.02 & 0.13 \(\pm\) 0.02 \(\lx@sectionsign\) ** & 0.39 \(\pm\) 0.04 \(\dagger\) ** \\ NAD & 0.037 \(\pm\) 0.002 & 0.037 \(\pm\) 0.004 & 0.049 \(\pm\) 0.001 \\ Monoacylglycerolglycerol & 0.75 \(\pm\) 0.08 & 0.30 \(\pm\) 0.02 \(\lx@sectionsign\) ** & 0.09 \(\pm\) 0.01 \\ \hline \hline \end{tabular} \(\lx@sectionsign\): significant differences between September and October and \(\dagger\): between October and November; \(\ast\)\(p<\) 0.05; \(\ast\)\(p<\) 0.01.  
\end{table} 
Table 1: Comparison among carrots harvested in September, October, and November for molecules resulting to be significant by PCA analysis, and one-way-ANOVA was employed to assess statistical differences. Figure 4: PC1 normalized loadings of purple carrot harvested in September, October, and November. Variables with \(p<\) 0.05 are presented in black and molecule abbreviations are reported in the Abbreviations. The results show a linear increase of leucine, isoleucine, valine, threonine, and tryptophan levels from September to November. On the contrary, the other amino acids have a different evolution: histidine decreases from September to October and increases in November; alanine increases in October and remains stable in November; glutamine and aspartic acid levels increase in November.