# Postharvest Evaluations of Blackcurrant Fruits with Chitosan and Ultraviolet A Treatments
## 3 Results and Discussion
### Total Polyphenol, Flavonoid, and Anthocyanin Content Changes Under Different Treatments  
Polyphenols are antioxidants and play an important role in the treatment and prevention of many diseases [50]. Postharvest processing and storage could influence the content of those compounds in foods [7; 51]. In this study, the results (Table 2) indicated that although the treatments of UVA, chitosan, and UVA-chitosan did not make significant changes on each antioxidant subgroup, since \(p\)-values were larger than 0.05, with time, each group's contents were enhanced in 15 days of storage, especially total flavonoids and anthocyanins. Flavonoids were significantly increased from 2.31 to 2.49 mg/g on average with a \(p\)-value of 0.014. Total anthocyanins were increased from 853.1 to 920.75 (\(\upmu\)g) on average with time, and the changes were significant with a \(p\)-value of 0.04. The total polyphenol contents were on average from 4.79 to 4.96 mg/g, but the changes showed no statistical differences during storage. High-performance liquid chromatography (HPLC) indicated the organic blackcurrants fruits from 'Ben Alder', 'Tiben', and 'Titania' contained about 10.3 mg/100 g phenolic acids and 178.8 mg/100 g flavonoids [52]. Compared with the previous research, 'Tofino' in this study contained more detected polyphenols and flavonoids. The content of biologically active compounds in blackcurrants depends on both genetic/variety background and environmental factors, which might contribute to the differences [53; 54]. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **Chinson** & **Tested** \\ \hline \begin{tabular}{c} Cynthia.5-displacement \\ \(0\) \\ \end{tabular}  & \ \begin{tabular}{c} ND \\ \(12343.1\pm 1.0^{*}\) \\ \end{tabular}  &
\begin{tabular}{c} ND \\ \(1308.2\pm 8.98^{*}\) \\ \(1308.2\pm 8.98^{*}\) \\ \(108.4\pm 2.1^{*}\) \\ \(108.4\pm 2.1^{*}\) \\ \(108.2\pm 2.4^{*}\) \\ \(108.2\pm 1.9^{*}\) \\ \(108.4\pm 2.0^{*}\) \\ \(108.2\pm 1.9^{*}\) \\ \(108.4\pm 1.9^{*}\) \\ \(108. In this study, on day 0, none of the samples were treated with UVA light yet, and only chitosan coatings were introduced. The results on day 0 indicated that most detected amounts of monomeric phenolics were not influenced by chitosan coatings, except peonidin and quercetin. The possible reasons might be that chitosan interfered with the phenolic extraction since chitosan could interact with phenolics in wines [65]. To understand the effects of solo and combined treatments from UVA and chitosan, the statistical analysis (Table 4) included with/without (w/wo) chitosan, w/wo UVA, and the interaction under the treatments. The results indicated that cyanidin-3-galactoside and rutin represented large amounts of monomeric phenolics, with more than 12,000 ug/g and 2000 ug/g per se. Cyanidin-3-galactoside was one of the most widespread functional anthocyanins in fruits, having multiple health benefits, such as anti-inflammatory, anticancer, antidiabetic, anti-toxicity, cardiovascular, and nervous protective capacities [66]. Apples and berries usually contain a large amount of this kind of anthocyanin. This study indicated that with time, cyanidin-3-galactoside content was enhanced significantly by both UVA and UVA-chitosan treatments with about 2500 and 5500 ug/g, increasing compared with the control on day 15. Interestingly, chitosan itself did not have an impact on the cyanidin-3-galactoside quantity, but UVA-chitosan-treated blackcurrants contained the largest amounts of cyanidin-3-galactoside. Chitosan (w/wo) comparisons indicated that chitosan itself did not cause cyanidin-3-galactoside changes, ranging from 16,792 to 17,520 on average. The reasons for the changes were mainly from UVA treatment, causing changes of about 4803 mg/g cyanidin-3-galactoside. Rutin composes the second largest amount of monomeric phenolics detected in blackcurrants in this research (Table 3).