## 3 Results
### Evolution of Carotenoids in Nebbiolo Grapes  
The compounds that mostly contributed to the total amount of carotenoids in Nebbiolo grapes were lutein and \(\beta\)-carotene. The evolution of each compound during ripening, both as \(\mu\)g berry\({}^{-1}\) (Figure 2a, Figure 3a, and Figure 4a) and as mg kg\({}^{-1}\) of fresh berries (Figure 2b, Figure 3b, and Figure 4b), is shown for both years 2012 and 2013 (Table 4). \(\bullet\) Lutein  
In 2012, at the first sampling date, at 24 days before veraison (dbV) similar amounts of lutein were detected in green berries from both west and south exposed vineyards (Figure 2a). Lutein concentration (mg kg\({}^{-1}\) of berries) and content (\(\mu\)g berry\({}^{-1}\)) remained then constant until the beginning of veraison (5 dpV, second sampling) (Figure 2a,b and Table 4). In 2013, at the first sampling (25 dbV), the lutein concentration (mg kg\({}^{-1}\)) was significantly higher in SouthV+ when compared to the other treatments and to the previous year. Afterwards, at the second sampling (5 dpV), lutein content decreased significantly only in south-exposed vineyards (Figure 2a,b, Table 4). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & & & & \multicolumn{2}{c}{**NHs**} & \\ \cline{4-8}  & \multirow{2}{*}{**Treatment**} & \multicolumn{2}{c}{**SDs Celsius (\({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Number of Hours NHT**} & & \\  & & & & & & **Number of Hours NHT** & & \\ \cline{3-8}  & & **15-25** & **25-35** & \(\geq\)**35** & **15-25** & **25-35** & \(\geq\)**35** & \\ \hline  & SouthV\(-\) & \(-\)0.54 a & 0.18 a & 0.12 a & \(-\)1.20 a & 0.50 a & 0.58 a & \(-\)0.56 a \\  & SouthV+ & \(-\)0.10 ab & \(-\)0.06 a & \(-\)0.05 a & \(-\)0.37 b & \(-\)0.02 a & 0.20 a & \(-\)0.18 b \\
2012 & WestV\(-\) & 0.40 b & 0.22 a & \(-\)0.43 a & 0.78 c & 0.45 a & \(-\)1.05 a & 0.29 c \\  & WestV+ & 0.23 b & \(-\)0.34 a & 0.36 a & 0.80 c & \(-\)0.92 a & 0.27 a & 0.44 c \\  & ** & ** & ** & ** & ** & ** & ** & ** \\ \hline  & SouthV\(-\) & \(-\)0.59 a & \(-\)0.23 a & 0.66 c & \(-\)0.59 a & \(-\)0.34 a & 0.63 c & \(-\)0.59 b \\  & SouthV+ & 0.03 b & 0.28 a & \(-\)0.07 b & \(-\)0.08 b & 0.12 a & \(-\)0.01 b & \(-\)0.22 b \\
2013 & WestV\(-\) & 0.23 b & 0.22 a & \(-\)0.34 a & 0.29 b & 0.28 a & \(-\)0.37 a & 0.40 c \\  & WestV+ & 0.32 b & \(-\)0.27 a & \(-\)0.24 ab & 0.37 b & \(-\)0.06 a & \(-\)0.26 a & 0.41 c \\  & ** & ** & ** & ** & ** & ** & ** & ** \\ \hline Treatment & & ** & ** & ** & ** & ** & ** & ** \\ Year & & ** & ** & ** & ** & ** & ** & ** \\ Year*Treatment & & ** & ** & ** & ** & ** & ** & ** & ** \\ \hline \hline \end{tabular}  
* For the same year, means followed by different letters are significant different for \(p<\) 0.05. ns—not significant;
* \(p<\) 0.05, *** \(p<\) 0.001 indicate the significance of differences among treatments.  
\end{table} 
Table 3: Normalized Sum of the Degrees Celsius (SDs), number of hours (NHs) related to the temperature ranges (15– 25; 25– 35; \(\geq\)35) and ST:SPAR; ST=summation of the maximum daily temperatures; SPAR=summation of the daily integrals of PAR. Concurrently to the increase of the berry weight and sugar concentration [31], a significant increase of lutein content per berry was noticed in both years reaching a peak at about 4 weeks after veraison, with the exception of SouthV- in 2013. This increase of lutein content was proportional to the vine vigor, thus more important for the most vigorous vines. After veraison, in SouthV- a minor increase was observed in 2012 and a constant trend in 2013, thus, at the time of the peak, significant differences were noticed between WestV+ and SouthV- in both seasons. At the final stage of ripening, a significant lutein degradation was observed for all treatment in 2012; significant differences between SouthV- (1.66 mg kg\({}^{-1}\) of berries or 2.78 ug berry\({}^{-1}\)) and WestV+ parcels (3.75 mg kg\({}^{-1}\) of berries or 6.78 ug berry\({}^{-1}\)).