## 3 Results and Discussion
### Impact of Drying Method and Grinding Degree on Color Characteristics  
Instrumental color measurements of tomato powder samples, expressed in CIELAB coordinates, as well as the values of BI, showed remarkable differences in color attributes depending on the drying method and the degree of grinding (Table 7). The lightness values (L*) ranged from 48.6 \(\pm\) 0.0 in sample TPW-VAC to 61.2 \(\pm\) 0.0 in TPW-70-M40. Higher L* values indicate a lighter appearance, while lower values reflect darker color shades, probably due to pigment degradation or surface changes during processing. Vacuum drying produced samples with the lowest L values and they decreased gradually as the grinding degree increased. The a* values (red/green axis) varied from 21.9 \(\pm\) 0.2 (TPW-70-M0) to 31.2 \(\pm\) 0.0 (TPW-VAC) and reflect the intensity of red coloration. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Compound** & **TPW-70-M0** & **TPW-70-M5** & **TPW-70-M9** & **TPW-70-M18** & **TPW-70-M40** \\
**Dx 50** & **732 μm** & 542 μm & **431 μm** & **388 μm** & **210 μm** \\ \hline \(\beta\)-Carotene (mg/100 g) & 11.1 \(\pm\) 0.6 \({}^{\mathrm{a}}\) & 11.3 \(\pm\) 0.4 \({}^{\mathrm{a}}\) & 11.9 \(\pm\) 0.4 \({}^{\mathrm{a}}\) & 12.8 \(\pm\) 0.3 \({}^{\mathrm{b}}\) & 11.9 \(\pm\) 0.1 \({}^{\mathrm{a}}\) \\ \hline Lycopene (mg/100 g) & 75.9 \(\pm\) 2.5 \({}^{\mathrm{a,b}}\) & 72.5 \(\pm\) 0.5 \({}^{\mathrm{a}}\) & 73.2 \(\pm\) 3.3 \({}^{\mathrm{a}}\) & 79.4 \(\pm\) 0.8 \({}^{\mathrm{b}}\) & 74.1 \(\pm\) 0.3 \({}^{\mathrm{a}}\) \\ \hline TP (mg GAE/100 g) & 174.9 \(\pm\) 2.8 \({}^{\mathrm{a}}\) & 211.8 \(\pm\) 12.8 \({}^{\mathrm{b}}\) & 209.9 \(\pm\) 0.8 \({}^{\mathrm{b}}\) & 221.4 \(\pm\) 7.0 \({}^{\mathrm{b}}\) & 230.2 \(\pm\) 17.7 \({}^{\mathrm{b}}\) \\ \hline TEAC (mg TE/100 g) & 58.4 \(\pm\) 5.3 \({}^{\mathrm{a}}\) & 54.2 \(\pm\) 0.7 \({}^{\mathrm{a}}\) & 49.8 \(\pm\) 2.6 \({}^{\mathrm{a}}\) & 63.4 \(\pm\) 8.4 \({}^{\mathrm{a}}\) & 61.7 \(\pm\) 9.7 \({}^{\mathrm{a}}\) \\ \hline Rutin (mg/kg) & 14.7 \(\pm\) 2.5 \({}^{\mathrm{a}}\) & 15.0 \(\pm\) 0.2 \({}^{\mathrm{a}}\) & 13.8 \(\pm\) 0.8 \({}^{\mathrm{a}}\) & 18.2 \(\pm\) 0.1 \({}^{\mathrm{b}}\) & 18.1 \(\pm\) 1.3 \({}^{\mathrm{b}}\) \\ \hline Kaempfer-3-rutinoside (mg/kg) & 0.81 \(\pm\) 0.41 \({}^{\mathrm{a}}\) & 0.81 \(\pm\) 0.34 \({}^{\mathrm{a}}\) & 1.26 \(\pm\) 0.29 \({}^{\mathrm{a}}\) & 1.36 \(\pm\) 0.20 \({}^{\mathrm{a}}\) & 1.06 \(\pm\) 0.13 \({}^{\mathrm{a}}\) \\ \hline Catechin (mg/kg) & 6.46 \(\pm\) 0.39 \({}^{\mathrm{d}}\) & 3.50 \(\pm\) 0.67 \({}^{\mathrm{c}}\) & 3.83 \(\pm\) 0.12 \({}^{\mathrm{c}}\) & 2.41 \(\pm\) 0.16 \({}^{\mathrm{b}}\) & 0.91 \(\pm\) 0.28 \({}^{\mathrm{a}}\) \\ \hline Chlorogenic acid (mg/kg) & 8.85 \(\pm\) 1.15 \({}^{\mathrm{b}}\) & 7.17 \(\pm\) 0.47 \({}^{\mathrm{a}}\) & 6.63 \(\pm\) 0.44 \({}^{\mathrm{a}}\) & 6.67 \(\pm\) 0.21 \({}^{\mathrm{a}}\) & 7.30 \(\pm\) 0.03 \({}^{\mathrm{a}}\) \\ \hline Caffe acid (mg/kg) & 7.03 \(\pm\) 0.84 \({}^{\mathrm{a}}\) & 7.49 \(\pm\) 0.44 \({}^{\mathrm{a}}\) & 8.83 \(\pm\) 0.23 \({}^{\mathrm{b}}\) & 7.96 \(\pm\) 0.04 \({}^{\mathrm{a,b}}\) & 7.22 \(\pm\) 0.33 \({}^{\mathrm{a}}\) \\ \hline \end{tabular}  
* The data are presented as mean \(\pm\) SD. Statistical analysis was performed using one-way ANOVA followed by [PERSON]’s post hoc test. Letters next to values indicate statistically significant differences between groups for each element (within the same row). TPW-70-Mx: tomato processing waste air dried at 70 \({}^{\mathrm{c}}\)C and milled for x sec; Dx 50: median diameter of particles.  
\end{table} 
Table 6: Impact of grinding degrees on the content of polyphenols, carotenoids, and the antioxidant activity of TPW.