## 3 Results and Discussion
### Blackcurrent Physicochemical Changes During Storage  
From the previous ANOVA analysis (Table 1), it has been concluded that pretreatments significantly influenced the SSC content of blackcurrants. In contrast, storage length had a significant impact on the pH and acid content during blackcurrant storage. In detail, the trend was listed in Table 2. The SSC results indicated that the 1 h and 2 h UVC pretreatments increased the SSC content by 0.27 to 0.30 \({}^{\circ}\)Brix on average, and both were significantly different (\(p<0.001\)) from 0 h and 0.5 h UVC pretreated blackcurrants. In summary, UVC pretreatment accelerated SSC changes in blackcurrants. This may be correlated with UVC stress-induced resistance in blackcurrant berries, which has been observed in other fruits and vegetables [41]. Further research is needed to determine whether the fruit possesses a defense against UVC irradiation, such as oxidase activities and expression. \begin{table}
\begin{tabular}{c c c c} \hline
**Pretreatment (UVC)** & **SSC (\({}^{\circ}\)Brix)** & \(p\)**-Value** & **F-Value** \\ \hline
0 h & 14.31 \(\pm\) 0.31 \({}^{\mathrm{b}}\) & & \\
0.5 h & 14.42 \(\pm\) 0.26 \({}^{\mathrm{b}}\) & 0.0001709 *** & 11.37 \\
1 h & 14.61 \(\pm\) 0.13 \({}^{\mathrm{a}}\) & & \\
2 h & 14.58 \(\pm\) 0.21 \({}^{\mathrm{a}}\) & & \\ \hline
**Storage Duration (days)** & pH & \(p\)**-Value** & **F-Value** \\ \hline
0 & 3.27 \(\pm\) 0.01 \({}^{\mathrm{c}}\) & & \\
5 & 3.27 \(\pm\) 0.02 \({}^{\mathrm{c}}\) & & \\
10 & 2.28 \(\pm\) 0.03 \({}^{\mathrm{c}}\) & 6.863 \(\times\) 10\({}^{-7}\)*** & 21.85 \\
15 & 3.29 \(\pm\) 0.01 \({}^{\mathrm{b}}\) & & \\
20 & 3.31 \(\pm\) 0.02 \({}^{\mathrm{a}}\) & & \\ \hline
**Storage Duration (days)** & **Acidity (\%)** & \(p\)**-Value** & **F-Value** \\ \hline
0 & 2.37 \(\pm\) 0.06 \({}^{\mathrm{a}}\) & & \\
5 & 2.40 \(\pm\) 0.09 \({}^{\mathrm{a}}\) & & \\
10 & 2.41 \(\pm\) 0.05 \({}^{\mathrm{a}}\) & 9.04 \(\times\) 10\({}^{-8}\)*** & 28.31 \\
15 & 2.39 \(\pm\) 0.06 \({}^{\mathrm{a}}\) & & \\
20 & 2.19 \(\pm\) 0.08 \({}^{\mathrm{b}}\) & & \\ \hline \end{tabular}  
* Means followed by the same letter within columns are not significantly different for each character of blackcurrants. Values are listed as the mean \(\pm\) standard deviation of replicates. Acidity is detected as citric acid (\%) with an Atago meter. The significance codes are *** \(p<0.001\) (the effect is highly statistically significant). The F-value indicates that the difference in the group means is substantially greater than the variability within each group.  
\end{table} 
Table 2: The changes in blackcurrant physicochemical characteristics during storage. Figure 2: UVC pretreatment affects the weight loss of blackcurrants during storage. Each treatment contained three replicates. Bars indicate the mean \(\pm\) standard deviations of the replicates. LSD (least significant differences) shows the means of the treatment differences. pH differential changes in blackcurrants were significant among the storage sampling days, ranging from 3.27 to 3.31 on average. Although the changes were minimal, with a 0.04 pH change, the longer the storage time, the higher the pH level in the blackcurrants. Acid differences across storage were also detected significantly (\(p<0.0001\)): the range of the changes was from 2.19% to 2.41% on average. In general, the acid content decreased over time, and the acids on day 20 were significantly different from those on other storage days. Several publications mention that UVC pretreatment has an influence with or without causing physicochemical changes. UVC, at doses of 2 and 4 J/cm\({}^{2}\) for postharvest treatment, did not influence the sugar, pH, or titratable acidity in tomatoes and apples, but improved their antioxidant capacities [42]. On the other hand, UVC pretreatment on peaches reduced the total soluble solids during storage, which may be because UVC can enhance antioxidants and reduce oxidative enzyme activities [37; 43].