# Bioactive Vitamin C Content from Natural Selected Fruit Juices
## 3 Results and Discussion
### Correlation between Vitamin C Content and Storage Conditions
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Fruit juices** & \multicolumn{3}{c}{**The Temperature of Storage in Glass Containers**} \\ \hline  & \multicolumn{2}{c}{t = 4 \({}^{\circ}\)C} & \multicolumn{2}{c}{t = 23 \({}^{\circ}\)C} & \multicolumn{2}{c}{t = \(-\)18 \({}^{\circ}\)C} \\ \hline \multirow{2}{*}{Grapefruit} & y = \(-\)1.34k + 36.18 & y = \(-\)1.66x + 36.38 & y = \(-\)1.71x + 35.07 \\  & R\({}^{2}\) = 0.9240 & R\({}^{2}\) = 0.9891 & R\({}^{2}\) = 0.8847 \\ \hline \multirow{2}{*}{Mandarin-clementine} & y = \(-\)2.78x + 25.92 & y = \(-\)31.6x + 26.04 & y = \(-\)2.73x + 24.96 \\  & R\({}^{2}\) = 0.9976 & R\({}^{2}\) = 0.9599 & R\({}^{2}\) = 0.9710 \\ \hline \multirow{2}{*}{Late Peach} & y = \(-\)0.12x + 8.63 & y = \(-\)0.31x + 8.62 & y = \(-\)0.52x + 9.13 \\  & R\({}^{2}\) = 0.9730 & R\({}^{2}\) = 0.9135 & R\({}^{2}\) = 0.9786 \\ \hline \multirow{2}{*}{Winter Apple} & y = \(-\)0.202x + 4.694 & y = \(-\)0.259x + 4.713 & y = \(-\)0.23x + 4.44 \\  & R\({}^{2}\) = 0.9030 & R\({}^{2}\) = 0.9357 & R\({}^{2}\) = 0.8202 \\ \hline \multirow{2}{*}{Winter Pear} & y = \(-\)0.055x + 6.755 & y = \(-\)0.095x + 6.755 & y = \(-\)0.11x + 6.79 \\  & R\({}^{2}\) = 0.9453 & R\({}^{2}\) = 0.9209 & R\({}^{2}\) = 0.9167 \\ \hline \multirow{2}{*}{Autumn Plum} & y = \(-\)0.13x + 7.32 & y = \(-\)0.201x + 7.367 & y = \(-\)0.15x + 7.17 \\  & R\({}^{2}\) = 0.8125 & R\({}^{2}\) = 0.9163 & R\({}^{2}\) = 0.9259 \\ \hline \multirow{2}{*}{**Fruit juices**} & \multicolumn{3}{c}{**The temperature of storage in plastic containers**} \\ \hline  & \multicolumn{2}{c}{t = 4 \({}^{\circ}\)C} & \multicolumn{2}{c}{t = 23 \({}^{\circ}\)C} & \multicolumn{2}{c}{t = \(-\)18 \({}^{\circ}\)C} \\ \hline \multirow{2}{*}{Grapefruit} & y = \(-\)1.61x + 35.87 & y = \(-\)1.75x + 35.15 & y = \(-\)1.83x + 35.03 \\  & R\({}^{2}\) = 0.9668 & R\({}^{2}\) = 0.9088 & R\({}^{2}\) = 0.8875 \\ \hline \multirow{2}{*}{Mandarin-clementine} & y = \(-\)2.74x + 25.28 & y = \(-\)2.98x + 25.44 & y = \(-\)2.8x + 25.02 \\  & R\({}^{2}\) = 0.9843 & R\({}^{2}\) = 0.9526 & R\({}^{2}\) = 0.9600 \\ \hline \multirow{2}{*}{Late Peach} & y = \(-\)0.38x + 9 & y = \(-\)0.34x + 8.66 & y = \(-\)0.52x + 9.13 \\  & R\({}^{2}\) = 0.9678 & R\({}^{2}\) = 0.9088 & R\({}^{2}\) = 0.9786 \\ \hline \multirow{2}{*}{Winter Apple} & y = \(-\)0.251x + 4.577 & y = \(-\)0.26x + 4.6 & y = \(-\)0.22x + 4.31 \\  & R\({}^{2}\) = 0.9313 & R\({}^{2}\) = 0.9548 & R\({}^{2}\) = 0.6676 \\ \hline \multirow{2}{*}{Winter Pear} & y = \(-\)0.106x + 6.7 & y = \(-\)0.105x + 6.685 & y = \(-\)0.119x + 6.779 \\  & R\({}^{2}\) = 0.7886 & R\({}^{2}\) = 0.7449 & R\({}^{2}\) = 0.9721 \\ \hline \multirow{2}{*}{Autumn Plum} & y = \(-\)0.156x + 7.042 & y = \(-\)0.225x + 7.325 & y = \(-\)0.17x + 7.1 \\  & R\({}^{2}\) = 0.6769 & R\({}^{2}\) = 0.9040 & R\({}^{2}\) = 0.7983 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: A decrease in vitamin C content in fruit juices at different storage temperatures (7 days). In fruit juices stored in glass containers, the concentration of vitamin C gradually decreased. Based on calculations from the data analysed at different temperatures (t\({}_{1}\) = 4 \({}^{\circ}\)C, t\({}_{2}\) = 23 \({}^{\circ}\)C, t\({}_{3}\) = \(-\)18 \({}^{\circ}\)C), Table 3 summarised the linear equations for the decrease in the vitamin C content (in mg) in the fruit per 100 g of fruit juice over a period of 7 days. The equations show that in glass containers at t\({}_{1}\) = 4 \({}^{\circ}\)C (t\({}_{2}\) = 23 \({}^{\circ}\)C, t\({}_{3}\) = \(-\)18 \({}^{\circ}\)C), mandarin-clementing juice has the highest loss of vitamin C content, i.e., \(-\)2.78 mg/100 g fruit juice (\(-\)3.16 mg/100 g fruit juice; \(-\)2.73 mg/100 g of fruit juice), and winter pear juice showed the lowest loss of vitamin C values, i.e., \(-\)0.055 mg/100 g of fruit juice (\(-\)0.095 mg/100 g of fruit juice; \(-\)0.11 mg/100 g of fruit juice).