## 3 Results and Discussion
### Optimal Waveband Selection Using ANOVA Analysis Results
#### 3.2.1 Development of Single-Waveband Algorithm (SWA)
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & & & & \multicolumn{3}{c}{**\#4-Finished SSS**} \\ \cline{3-10}  & & \multicolumn{2}{c}{**Ratio**} & \multicolumn{2}{c}{**Calibration**} & \multicolumn{2}{c}{**Validation**} \\ \cline{4-10}  & & \multicolumn{2}{c}{**Waveband [nm]**} & \multicolumn{2}{c}{**F-Value**} & \multicolumn{2}{c}{**No. of Spectra**} & \multicolumn{2}{c}{**TH**} & \multicolumn{2}{c}{**Accuracy [\%]**} & \multicolumn{2}{c}{**No. of Spectra**} & \multicolumn{2}{c}{**Accuracy [\%]**} \\ \hline \multirow{6}{*}{Honeydew} & original & 612 & 676 & 3043 & 1702 & 0.55 & 90.64 & 425 & 90.61 \\  & 1:5 & 464 & 640 & 1349 & 1636 & 1.27 & 90.43 & 408 & 88.28 \\  & 1:10 & 464 & 640 & 1053 & 1531 & 1.11 & 90.53 & 382 & 87.74 \\  & 1:20 & 476 & 612 & 126 & 2052 & 0.74 & 82.77 & 512 & 81.93 \\  & 1:50 & 580 & 648 & 54 & 1460 & 0.50 & 62.19 & 365 & 62.46 \\  & 1:100 & 540 & 664 & 311 & 1465 & 0.33 & 59.61 & 366 & 59.60 \\ \hline \multirow{6}{*}{Orange} & original & 472 & 612 & 387 & 1844 & 0.29 & 97.98 & 461 & 97.86 \\  & 1:5 & 476 & 664 & 1942 & 1771 & 2.06 & 91.03 & 442 & 91.94 \\  & 1:10 & 480 & 612 & 1326 & 1592 & 1.64 & 90.63 & 397 & 89.28 \\  & 1:20 & 464 & 600 & 1112 & 1987 & 1.13 & 89.03 & 496 & 89.94 \\  & 1:50 & 608 & 676 & 700 & 1527 & 0.22 & 88.35 & 381 & 88.14 \\  & 1:100 & 560 & 664 & 1779 & 1775 & 0.50 & 85.60 & 443 & 87.73 \\ \hline \multirow{6}{*}{Apple} & original & 564 & 676 & 638 & 1672 & 0.14 & 84.12 & 418 & 84.18 \\  & 1:5 & 456 & 564 & 256 & 1861 & 0.26 & 74.19 & 465 & 74.37 \\  & 1:10 & 472 & 548 & 104 & 1763 & 0.22 & 74.03 & 440 & 73.93 \\  & 1:20 & 500 & 612 & 70 & 2076 & 0.41 & 64.86 & 518 & 64.74 \\  & 1:50 & 504 & 612 & 81 & 1570 & 1.48 & 65.11 & 392 & 61.30 \\  & 1:100 & 488 & 656 & 280 & 1431 & 0.24 & 58.17 & 357 & 58.05 \\ \hline \multirow{6}{*}{Watermelon} & original & 464 & 728 & 428 & 2246 & 0.59 & 96.53 & 561 & 96.66 \\  & 1:5 & 464 & 616 & 1452 & 1555 & 1.08 & 90.52 & 388 & 84.17 \\ \cline{1-1}  & 1:10 & 488 & 580 & 135 & 1551 & 0.55 & 89.31 & 387 & 89.81 \\ \cline{1-1}  & 1:20 & 488 & 580 & 53 & 1984 & 0.55 & 88.59 & 495 & 89.15 \\ \cline{1-1}  & 1:50 & 580 & 676 & 158 & 1576 & 2.48 & 82.60 & 394 & 82.84 \\ \cline{1-1}  & 1:100 & 548 & 660 & 492 & 1471 & 1.01 & 74.52 & 367 & 76.86 \\ \hline \hline \end{tabular} Note: TH = Threshold value.  
\end{table} 
Table 4: Optimal two wavebands and discrimination algorithm results using the two-waveband method for #4-finished SSS. Residue Detection Algorithm for Orange  
For the SWA developed to detect orange residue on the surface of 2B-finished SSS, the optimal wavebands for the original juice, and the 1:5, 1:10, 1:20, and 1:50 dilution samples were close to 470 nm, and the threshold values for detecting the residues using the selected wavebands were 1891, 1242, 800, 495, and 332, respectively (Figure S1b). The calibration accuracies were 92.30%, 90.88%, 87.52%, 85.40%, and 80.08%, and the validation accuracies were 92.55%, 91.04%, 87.68%, 85.67%, and 80.01%, respectively. The optimal waveband for the original juice was 644 nm, the threshold value was 1585, the calibration accuracy was 72.55%, and the validation accuracy was 72.67%. The 470-nm and 644-nm wavebands were related to carotenoids and chlorophyll-\(b\), respectively [35; 36; 37]. According to the SWA developed to detect orange residue on the surface of #4-finished SSS, the optimal waveband for the original juice was 492 nm, the threshold value was 620, the calibration accuracy was 98.23%, and the validation accuracy was 98.10% (Figure S2b). The optimal waveband for the 1:5, 1:10, and 1:20 dilution samples was 464 nm, and the threshold values were 1422, 1003, and 454, respectively. The calibration accuracies were 91.15%, 91.47%, and 92.98%, and the validation accuracies were 98.10%, 91.37%, and 91.66%, respectively. The optimal wavebands for the 1:50 and 1:100 dilution samples were 660 nm, and the threshold values were 577 and 994, respectively.