## 3 Results and Discussion
### Deficit Irrigation Effect on Titratable Acidity, Total Soluble Solids, Sugars, and Organic Acid
Finally, ascorbic acid or vitamin C ranged between 0.29 in control samples and 0.35 g kg\({}^{-1}\) in RDI in the 1 st week of harvest, 0.82-1.02 g kg\({}^{-1}\) in 2 nd week, 0.96-1.03 g kg\({}^{-1}\) in 3 rd week, 1.22-1.17 g kg\({}^{-1}\) in 4 th week, 0.98-0.93 g kg\({}^{-1}\) in 5 th week, and 0.97-1.04 g kg\({}^{-1}\) in the 6 th week. It can be observed a small increase in Vitamin C in almost all weeks, although without statistical significance. These values were higher than those reported in cultivar Ryna(ryna) (-0.24 g kg\({}^{-1}\)) and are considered among the tomato cultivar with the highest content, as the Vitamin C level of tomatoes was reported to range between 0.08 and 1.2 g kg\({}^{-1}\)[33; 31]. Regarding deficit irrigation, authors reported an increase in this compound with the reduction in the volume of irrigation water in cultivar Ryna(ryna) (0.17, 0.23, and 0.29 g kg\({}^{-1}\) in 1.0, 0.8 and 0.6 Etc, which meant 460, 390, and 320 mm of water through the growth period). Using a greater volume of irrigation water than in the present study, the authors reported an increase in the Vitamin C content, which was not clearly observed in this study; this might suggest that Vitamin C level can be affected by water stress in a different way depending on the cultivar. The increase in sugars in stress conditions were related to the restricted water uptake into the fruit, lower content of water in the fruit and thus, a greater solute concentration [31]. Authors also reported a simultaneous increase in fruit fresh weight and TSS under water deficit conditions, suggesting additional active sugar accumulation under limited water supply [9]. On the other hand, fruit acidity accumulation with water stress has been mainly attributed to a simple concentration effect through the literature [9]. Additionally, the osmotic adjustments which involves active synthesis of sugars and organic acids under water stress, was another mechanism likely to affect fruit acidity. Other authors found that citrate content increased as tomato fruit approached maturity under both irrigated and mild drought conditions (50% of crop Etc). The trends describing the effect of the RDI on the organic acids and sugars profile seem to agree with the hypothesis  
Figure 2: Quadratic correlation between: Sugars (glucose and fructose) and total soluble solids (TSS). Four repetitions per treatment were used for the correlation. established before, reinforcing the idea of an advanced ripening process for RDI tomatoes cultivar \"Summerbrix\". Overall, the metabolism of sugars and acids largely determines the sugar: acid ratio and are responsible for the simultaneous sweet and sour taste of tomatoes. A balance between these compounds produces the best flavor; because all the following combinations (i) low sugar-high acid; (ii) high sugar-low acid; and both (iii) low sugar-low acid concentrations) generates bitter-taste, bland-taste, and tasteless fruits, respectively. Finally, Vitamin C in plant it is necessary to balance the oxidative stress while in humans is thought to lower the risk of cardiovascular diseases and certain cancers. According to European Commission (EC) the nutrition claim \"high in vitamin C\" can be only used if the product contains 0.24 g kg\({}^{-1}\) Vitamin C [34; 35]. In this case, it can be said that the tomatoes of cultivar \"Summerbrix\" can be sold as high in Vitamin C, because presented a higher content of this antioxidant than the threshold established by the EC. Vitamin C is an important antioxidant helping in detoxifying reactive oxygen species due to its ability to donate an electron in many enzymatic and non-enzymatic reactions [31]. Finally, this compound content was maintained in the present study except for the 1 st week in which was increased by the RDI treatment, as well as reported by other authors [31]. However, some components involved in the antioxidants generation it might be contradictory [34]; for instance, water deficit during cropping may increase the Vitamin C and perhaps reduce the lycopene.