## 2 Nutritional Properties of Sweet and Sour Cherries
### Effect of pre-harvest and post harvest conditions on cherry nutritional properties
#### 2.2.1 Effect of pre-harvest factors  
Pre-harvest factors and temperature, light intensity, fruit crops maturity may affect the content and stability of phytochemicals and the nutritional value in cherries. Light intensity increases levels of ascorbic acid and different growing temperatures (day/night) also affect total phenolic content. High temperature growing conditions (25/30 \({}^{\circ}\)C) significantly enhance anthocyanin and total phenolic content [22]. Also soil types, composts, mulching and fertilization influence the water and nutrient supply to the plant and can affect the nutritional composition of the harvested fruit.  
Actually, in cool growing areas interest is increasing in growing cherries under plasticulture systems to prevent cherry cracking and to favour harvest operations. This cultivation system can influence canopy and soil temperature, quantity and quality of transmitted, reflected or absorbed light, with a possible difference in fruit growth, development, quality or carbohydrate metabolism. For example, in strawberry black plastic mulching consistently resulted in higher flavonoids, anthocyanin and total phenolic content compared to the traditional matted row culture system [22].  
\begin{table}
\begin{tabular}{l c c} \hline \multirow{2}{*}{**Cultivar**} & **Total phenols (mg** & **Total anthocyanins** \\  & **GAE/100g fresh cherries )** & **(CGE/100g fresh cherries)** \\ \hline
**sweet Brooks\({}^{\mathbf{a}}\)** & 60 \(\pm\) 13 & 10 \(\pm\) 2 \\
**sweet Newstar\({}^{\mathbf{a}}\)** & 75 \(\pm\) 14 & 20 \(\pm\) 5 \\
**sweet Black Gold\({}^{\mathbf{b}}\)** & 92 \(\pm\) 12 & 30 \(\pm\) 9 \\
**sweet Hedelfingen\({}^{\mathbf{b}}\)** & 96 \(\pm\) 20 & 40 \(\pm\) 7 \\
**sweet Regina\({}^{\mathbf{b}}\)** & 104 \(\pm\) 6 & 41 \(\pm\) 2 \\
**sweet Hartland\({}^{\mathbf{b}}\)** & 147 \(\pm\) 19 & 76 \(\pm\) 12 \\
**sweet Cristalina\({}^{\mathbf{a}}\)** & 155\(\pm\)20 & 79 \(\pm\) 5 \\
**sour Balaton\({}^{\mathbf{b}}\)** & 254.1 \(\pm\) 6.0 & 45 \(\pm\) 2.3 \\
**sour Danube\({}^{\mathbf{b}}\)** & 162 \(\pm\) 1 & 65 \(\pm\) 3 \\
**sour Schattenmorelle\({}^{\mathbf{b}}\)** & 295 \(\pm\) 34 & 72 \(\pm\) 6 \\
**sour Sumadinka\({}^{\mathbf{b}}\)** & 312 \(\pm\) 8 & 109 \(\pm\) 6 \\ \hline \end{tabular}
\end{table}
Table 2: Total anthocyanins and total phenols in different cultivars of sweet or sour cherries \({}^{\mathbf{a}}\) from [PERSON] _et al_ (2009); \({}^{\mathbf{b}}\) from [PERSON] _et al._ (2005); GAE, gallic acid equivalent; CGE, cyanidin-3-glucoside equivalents.  
Actually in all cherry growing regions different rootstock are used for many reasons related to climate, environment, field and orchard training. 'PiKu 1' and 'Weiroot 13' rootstocks gave fruits of Lapins cultivar with significantly higher phenolic acid and flavonoid content [23]. Higher amounts of phenols in sweet cherry fruits grown on heterogenic graft combinations might be attributed to the adjustment of the metabolism to genetically different between rootstocks and varieties, which causes higher amounts of metabolic stress [24]. Trees of different vigor can produce sweet cherry fruits with different phenolic acid and flavonoid content. Wild growing sweet cherry genotypes have different nutritional properties and are relatively higher in blackish skin colored fruits than in light skin colored ones [25].