## 2 Materials and Methods
### HPLC-DAD-MS Analyses of Carotenoids
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Peak** & **Compound** & **k\({}^{\prime}\)** & **\(\lambda_{\text{max}}\) (nm)** & **\%** & **D\({}_{\text{B}}\)/D\({}_{\text{B}}\)\({}^{\text{b}}\)** & **[M+HI\({}^{\star}\)(m/z)** & **[M] + (m/z)** & **MS\({}^{2}\) Product** \\  & & & **(III/II)\({}^{\star}\)** & & & & **Ions m/z** \\ \hline
1 & violaxanthin like structure & 2.78 & 418;440;470 & 84 & 601.5 & 600.1 & 583.5, 565.5, & 509.5, 491.5, & 221.1 \\ \hline
2 & violaxanthin & 2.92 & 416; 440; 468 & 86 & 601.5 & 600.1 & 583.5, 565.5, & 509.5, 491.5, \\  & & & & & & & 221.1 \\ \hline
3 & (8\({}^{\prime}\)R)-neochrome & 3.01 & 400; 422; 450 & 88 & 601.5 & 600.1 & 583.2, 565.3, & 509.5, 221.1 \\ \hline
4 & (9\({}^{\prime}\)Z)-neaxanthin & 3.06 & 414; 436; 464 & 86 & 601.5 & 600.1 & 583.2, 565.3, & 509.5, 221.1 \\ \hline
5 & (8\({}^{\prime}\)S)-neochrome & 3.12 & 400; 422; 450 & 88 & 601.5 & 600.1 & 583.2, 565.3, & 509.5, 221.1 \\ \hline
6 & 5,6-epoxylitein & 3.19 & 416; 440; 468 & 90 & 585.4 & 584.2 & 567.1, 493.1, & 221.1 \\ \hline
7 & luteoxanthin & 3.33 & 399; 422; 448 & 94 & 601.5 & 600.1 & 583.2, 221.1 \\ \hline
8 & lutein like structure & 3.42 & (425); 446; 474 & 568.9 & 567.9 & 550.9, 532.9, & 476.4, 429.4 \\ \hline
9 & \(Z\) lutein like structure & 3.47 & 328; 436; 464 & 568.9 & 567.9 & 550.9, 532.9, & 476.4, 429.4 \\ \hline
10 & (8\({}^{\prime}\)S)-auxxanth & 3.64 & 380; 402; 426 & 98 & 601.5 & 600.1 & 583.5, 565.5, & 509.5, 491.5, \\  & & & & & & & 221.1 \\ \hline
11 & chlorophyll b & 3.70 & 258; 314; 342; 466; 600.650 & & & & \\ \hline
12 & (_allE_)-lutein & 3.75 & (422); 446; 472 & 40 & 568.9 & 567.9 & 550.9, 532.9, & 476.4, 429.4 \\ \hline
13 & zeaxanthin & 4.00 & (425); 452; 476 & 22 & 568.9 & 567.9 & 550.9, 532.9, & 476.4, 429.4 \\ \hline
14 & (9Z) or & 4.16 & 330; (422); 50 & 0.075 & 568.9 & 567.9 & 550.9, 532.9, & 476.4, 429.4 \\  & (9\({}^{\prime}\)Z)-lutein & & 440; 468 & & & & 476.4, 429.4 & \\ \hline
15 & chlorophyll a & 4.31 & 336; (885); & & & & \\  & & (471); 432; & & & & & \\  & & & 618; 665 & & & & \\ \hline IS & \(\beta\)-apo-8\({}^{\prime}\)-carotenal & 4.50 & 460 & & & & \\ \hline
16 & phenophytin b & 5.46 & (417); 436; & & & 885 & \\  & & & 527; 600; 654 & & & & \\ \hline
17 & phenophytin a & 5.59 & 410; 506; 536; & & & 871 & \\  & & & 666 & & & & \\ \hline
18 & \(\beta\)-carotene & 5.98 & (430); 452; & 25 & 536.9 & 535.9 & 444.2, 430.3, & 399.3 \\  & & & 478 & & & & 399.3 \\ \hline
19 & (9Z)- \(\beta\)-carotene & 6.25 & 342; (424); & 17 & 0.03 & 536.9 & 535.9 & 444.2, 430.3, & 399.3 \\  & & 446; 474 & & & & 399.3 & \\ \hline \hline \end{tabular} \({}^{a}\)\(\%\)III/I is the ratio of the height of the longest-wavelength absorption peak, designated III, and that of the middle absorption peak, designated as II, taking the minimum between the two peaks as a baseline [8]; \({}^{b}\) The \(Q\) ratio is the quotient between the cis peak band and band II (normally \(\lambda_{\text{max}}\)) [24]. The fragments corresponding to the base peak in MS\({}^{2}\) spectra were underlined.  
\end{table} 
Table 1: HPLC-DAD-MS (ESI\({}^{+}\)) characteristics of carotenoids in grapes. To evaluate linearity, calibration curves with seven concentration points for each compound were prepared separately. Calibration was performed by a linear regression of peak-area ratios of the carotenoids to the internal standard (\(\beta\)-apo-8'-carorenal) versus the respective standard concentration. The precision of the method was determined by calculating the intraday and interday repeatability, expressed as standard deviation (SD) (\(\sigma\)) and relative standard deviation (RSD) in terms of retention times and peak width (W\({}_{1/2}\)), by the injection of four different replicates of extracts on the same day or over three consecutive days.