## 3 Results and Discussion
### Microstructure of Fresh-Cut Parsley during Storage  
A microscopic observation of the structure of the examined parsley was carried out immediately after the coating process and after 28 days of refrigerated storage (Figure 1). It was observed that the parsley discs immediately after coating and the uncoated ones had numerous open pores. In addition, the film-forming solution was inside the pores of the tissues. The samples coated with the whey protein isolate showed the most drying on their surface after 28 days of storage. The exception was the parsley rings coated with the whey protein isolate with the addition of jojoba oil at a concentration of 2%. The loss of texture  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Storage Time**} & \multicolumn{4}{c}{**Flavonoids (mg QE/g d.m.)**} \\ \cline{2-5}  & \multicolumn{4}{c}{**Type of Material**} \\ \cline{2-5}  & **Control** & **WPI** & **WPI\_JO\_1\%** & **WPI\_JO\_2\%** \\ \hline
0 & 22.61 \(\pm\) 0.32 \({}^{\mathrm{a,B}}\) & 21.08 \(\pm\) 0.06 \({}^{\mathrm{a,A}}\) & 26.22 \(\pm\) 0.04 \({}^{\mathrm{a,D}}\) & 23.65 \(\pm\) 0.24 \({}^{\mathrm{a,C}}\) \\
7 & 24.72 \(\pm\) 0.52 \({}^{\mathrm{b,A}}\) & 25.40 \(\pm\) 0.12 \({}^{\mathrm{b,B}}\) & 27.16 \(\pm\) 0.33 \({}^{\mathrm{a,C}}\) & 34.00 \(\pm\) 0.22 \({}^{\mathrm{b,D}}\) \\
14 & 37.91 \(\pm\) 0.15 \({}^{\mathrm{e,A}}\) & 40.81 \(\pm\) 0.13 \({}^{\mathrm{e,B}}\) & 43.27 \(\pm\) 0.14 \({}^{\mathrm{d,C}}\) & 48.43 \(\pm\) 0.07 \({}^{\mathrm{e,D}}\) \\
21 & 33.80 \(\pm\) 0.30 \({}^{\mathrm{c,A}}\) & 32.36 \(\pm\) 0.11 \({}^{\mathrm{c,A}}\) & 39.55 \(\pm\) 1.37 \({}^{\mathrm{c,C}}\) & 37.28 \(\pm\) 0.17 \({}^{\mathrm{c,B}}\) \\
28 & 35.53 \(\pm\) 0.19 \({}^{\mathrm{d,A}}\) & 39.73 \(\pm\) 0.03 \({}^{\mathrm{d,C}}\) & 36.89 \(\pm\) 0.58 \({}^{\mathrm{b,B}}\) & 40.60 \(\pm\) 0.16 \({}^{\mathrm{d,D}}\) \\ \hline \hline \end{tabular} Mean values with standard deviations in brackets. Different superscript letters (\({}^{\mathrm{a-C}}\)) within the same column or (\({}^{\mathrm{a-D}}\)) within the lines indicate significant differences between the samples (\(p<0.05\)).  
\end{table}
Table 5: Flavonoid content of samples uncoated (control) and coated with whey protein isolate (WPI) coatings incorporated with jojoba oil (JO) of fresh-cut root parsley during storage.  
and the integrity of fresh produce is due to enzymatic degradation and is associated with a decrease in consumer acceptability [31]. The softening of fruits and vegetables is related to the activity of enzymes. The higher the activity, the faster it can be noticed. Visible changes in the structure on the surface of freshly cut vegetables and fruits also result from the loss of water, which reduces the firmness of cells [29]. [PERSON] et al. [32] mentioned that the use of chitosan coatings reduced the loss of texture in green beans, zucchini, and strawberries. The addition of stabilizers (xanthan, pectin, and whey protein isolate) to nanoemulsions has a positive effect on maintaining the appropriate structure, preventing water loss, resulting in a cross-linked network, and increasing mechanical strength. [PERSON] et al. [33] observed that freeze-dried carrots were characterized by an uneven surface coverage, revealing empty areas of cells, while other researchers observed that the use of UV radiation on coatings made based on chitosan allows for the preservation of a better cell structure in which less intercellular space is visible and damage is reduced [34].