## 3 Results and Discussion
### UVC Pretreatment Effects on Blackcurrant Postharvest Storage  
The blackcurrant weight loss percentage continued to increase across postharvest storage, from 0% on day 0 (before storage) to approximately 2.0% weight loss on day 20 (Figure 2). It was noticeable that 2 h of UVC pretreatment reduced weight loss compared to other pretreatments, possibly because UVC has a positive effect on reducing weight loss with longer pretreatment, which may be attributed to a reduced respiratory rate or enzymatic activities. Further research is needed to address this issue and determine the underlying reasons. Besides influencing the fruit transpiration and respiration rate, UVC effects might be related to the blackcurrant fruit structure, especially the berry skin. Sunburn in warm or hot weather can alter skin structures, making berry transpiration and respiration more difficult during storage [35, 36]. Further research at the cellular level could help determine the detailed modification under UVC radiation. In this study, other pretreatments did not appear to affect weight loss significantly compared to the control treatment. The LSD revealed that there were about 10% differences among the pretreatments.  
Preharvest and postharvest UVC treatments were studied on fruit and vegetable varieties. Ten and twenty minutes of UVC (28.8 kJ m\({}^{-2}\)) treatments on peaches positively controlled weight loss [37]. UVC treatments (0.32, 0.97, 2.56, 4.16, and 4.83 kJ m\({}^{-2}\) at 254 nm) on tomatoes resulted in less weight loss compared with the control treatment (no UVC), whereas 0.97 kJ m\({}^{-2}\) had fewer effects compared to other UVC treatments [38]. The publications indicated that UVC with specific doses could have a positive impact on fruit weight loss control, which corresponded to this study, where only 2 h of UVC had significant weight loss control. To more effectively control the blackcurrant weight loss during postharvest storage, other strategies can be combined, such as hydro-cooling and biopolymers (e.g., chitosan) [39, 40].  
\begin{table}
\begin{tabular}{c c c c} \hline
**Factor** & **Pretreatment** & **Storage Time** & **Pretreatment \(\times\) Storage Time** \\ \hline df & 3 & 3 for weight loss percentage or 4 for others & 6 or 8 \\ Weight loss (\%) & 1.053 \(\times\) 10\({}^{-5}\)*** & \textless{}2.2 \(\times\) 10\({}^{-16}\)*** & ns \\ SSC (\({}^{\circ}\)Brix) & 0.0001709 *** & ns & 6.934 \(\times\) 10\({}^{-5}\)*** \\ pH & ns & 6.863 \(\times\) 10\({}^{-7}\)*** & 5.569 \(\times\) 10\({}^{-5}\)*** \\ Acid (\%) & ns & 9.039 \(\times\) 10\({}^{-8}\)*** & 0.001989 ** \\ Firmness & ns & \textless{}2.2 \(\times\) 10\({}^{-16}\)*** & ns \\ Polyphenol content & ns & 0.058 & ns \\ Ascorbic acid content & ns & 0.004 ** & ns \\ DPPH & ns & 0.00032 *** & 0.04463 * \\ FRAP & ns & 2.712 \(\times\) 10\({}^{-7}\)*** & 0.04384 * \\ Mold & 5.97 \(\times\) 10\({}^{-7}\)*** & \textless{}2.2 \(\times\) 10\({}^{-16}\)*** & ns \\ \hline \end{tabular} Note: The characteristics analyzed in blackcurrants include weight loss, SSC, pH, acid, firmness, polyphenol, ascorbic acid, DPPH values, FRAP values, and mold populations. The significance codes are *** \(p<0.001\) (the effect is highly statistically significant); ** \(p<0.01\) (the effect is statistically significant at the 1% level); * \(p<0.05\) (the effect is statistically significant at the 5% level); and ns indicates the effects not statistically significant at the 5% level). There were four pretreatments in this study: 0 h UVC, 0.5 h UVC, 1 h UVC, and 2 h UVC. Storage time points are days 0, 5, 10, 15, and 20. For weight loss, the df of storage time is 3, and the df of Pretreatment \(\times\) Storage time is 6. For other characteristics, the df of storage time is 4, and the df of Pretreatment \(\times\) Storage time is 8.  
\end{table}
Table 1: Analysis of variance (\(p\)-values) for the significance of pretreatment influence on blackcurrant characteristics during postharvest storage.