## 3 Results
### Characteristics of Fresh and Packed Nettle Leaves
#### 3.4.3 Photosynthetic Pigments  
When looking at the results of the photosynthetic pigment content, a significant influence of the interaction of the factors (D \(\times\) M, \(p\)\(\leq\) 0.0001), but also of each individual factor (\(p\)\(\leq\) 0.0001) was observed. As can be seen from the results shown in Figure 5a, the highest chlorophyll a (Chl_a) and chlorophyll b (Chl_b) content was determined in the samples packed in LDPE after 6 days of storage with values of 0.77 and 0.37 mg/g, respectively, while the highest total chlorophyll content (TCh) was recorded in both LDPE and BOPP after 6 days with no significant difference between samples. The lowest TCh and Chl_a content was measured after 14 days, in LDPE material, while the lowest Chl_b content in the same period was in nettle leaves packaged in PLA material. The highest total carotenoid content (TCa) was determined in LDPE material after 6 days of storage. Considering packaging material, as an individually observed factor (Figure 5b), all analyzed chlorophyll pigment content was the highest in nettle leaves packed in BOPP material, with the lowest Chl_a and TCh content in PA/PE material and Chl_b content in PLA material. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \(L^{\star}\) & \(a^{\star}\) & \(b^{\star}\) & \(\Delta E\) \\ \hline FRESH & 43.92 \(\pm\) 0.8 & \(-\)14.15 \(\pm\) 0.05 & 23.12 \(\pm\) 1.17 & - \\ \hline \multicolumn{5}{c}{Results considering combinations of factors} \\ \hline  & & 6 days of storage & & \\ \hline BOPP & 42.96 \(\pm\) 0.70 abc & \(-\)13.52 \(\pm\) 0.32 b & 21.17 \(\pm\) 1.76 bc & 2.29 \(\pm\) 1.85 bc \\ LDPE & 43.37 \(\pm\) 0.3 abc & \(-\)14.28 \(\pm\) 0.56 b & 23.03 \(\pm\) 0.13 ab & 0.74 \(\pm\) 0.28 c \\ PA/PE & 45.41 \(\pm\) 2.14 a & \(-\)13.6 \(\pm\) 0.81 b & 23.93 \(\pm\) 1.75 a & 2.81 \(\pm\) 1.09 bc \\ PLA & 40.49 \(\pm\) 0.96 c & \(-\)13.54 \(\pm\) 1.29 b & 20.36 \(\pm\) 1.35 c & 4.66 \(\pm\) 1.18 b \\ \hline \multicolumn{5}{c}{14 days of storage} \\ \hline BOPP & 43 \(\pm\) 0.92 abc & \(-\)14.42 \(\pm\) 0.65 b & 24.12 \(\pm\) 1.30 a & 1.93 \(\pm\) 0.49 c \\ LDPE & 44.49 \(\pm\) 2.14 ab & \(-\)12.96 \(\pm\) 0.89 b & 22.61 \(\pm\) 1.85 abc & 2.74 \(\pm\) 0.71 bc \\ PA/PE & 35.85 \(\pm\) 2.22 d & \(-\)9.39 \(\pm\) 1.63 a & 15.4 \(\pm\) 1.44 d & 12.15 \(\pm\) 3.01 a \\ PLA & 42.21 \(\pm\) 1.92 bc & \(-\)13.12 \(\pm\) 0.82 b & 21.34 \(\pm\) 0.98 bc & 3.14 \(\pm\) 1.09 bc \\ \hline \multicolumn{5}{c}{Results considering individual factors} \\ \hline  & & Days of storage & & \\ \hline
6 & 43.06 \(\pm\) 2.11 a & \(-\)13.73 \(\pm\) 0.78 b & 22.12 \(\pm\) 1.92 a & 2.63 \(\pm\) 1.80 b \\
14 & 41.39 \(\pm\) 3.80 b & \(-\)12.48 \(\pm\) 2.15 a & 20.87 \(\pm\) 3.66 b & 4.99 \(\pm\) 4.56 a \\ \hline \multicolumn{5}{c}{Packaging material} \\ \hline BOPP & 42.98 \(\pm\) 0.73 ab & \(-\)13.97 \(\pm\) 0.68 b & 22.65 \(\pm\) 2.13 a & 2.11 \(\pm\) 1.23 bc \\ LDPE & 43.93 \(\pm\) 1.50 a & \(-\)13.62 \(\pm\) 0.98 b & 22.82 \(\pm\) 1.19 a & 1.74 \(\pm\) 1.19 c \\ PA/PE & 40.63 \(\pm\) 5.58 c & \(-\)11.5 \(\pm\) 2.57 a & 19.67 \(\pm\) 4.89 b & 7.48 \(\pm\) 5.50 a \\ PLA & 41.35 \(\pm\) 1.65 bc & \(-\)13.33 \(\pm\) 1.00 b & 20.85 \(\pm\) 1.19 b & 3.9 \(\pm\) 1.31 b \\ \hline \multicolumn{5}{c}{Significance of varied factors} \\ \hline D & 0.0243 & 0.0036 & 0.0492 & 0.0016 \\ M & 0.0127 & 0.0011 & 0.0045 & \(\leq\)0.0001 \\ D \(\times\) M & \(\leq\)0.0001 & 0.0013 & \(\leq\)0.0001 & \(\leq\)0.0001 \\ \hline \hline \end{tabular} Values are represented as means of nine replicates \(\pm\) standard deviation. Different superscript letters (a–d) indicate statistically significant differences between samples at \(p\)\(<\) 0.05. \(L^{\star}\)—lightness, \(a^{\star}\)—green–red components, \(b^{\star}\)—blue–yellow components, \(\Delta E\)—color difference, D—days of storage, M—packaging material, D \(\times\) M—interaction of days of storage and packaging material.  
\end{table} 
Table 3: Chromaticity parameters of nettle leaves packed in different packaging materials and stored for 14 days.