## 3 Results and Discussion
### Bulk Density of Fruit Fibres and Pomace  
The results presented that apple fibre was characterised by the highest bulk density among the fibres, which was 0.5146 g/cm\({}^{3}\) in the loose state and 0.6625 g/cm\({}^{3}\) after shaking. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sample** & \(L^{\star}\) & \(a^{\star}\) & \(b^{\star}\) \\ \hline
**chokeberry fibre** & 42.16 \(\pm\) 0.25 \({}^{\text{c}}\) & 12.70 \(\pm\) 0.08 \({}^{\text{e}}\) & 4.73 \(\pm\) 0.03 \({}^{\text{c}}\) \\ \hline
**chokeberry pomace** & 36.54 \(\pm\) 0.25 \({}^{\text{a}}\) & 8.53 \(\pm\) 0.11 \({}^{\text{b}}\) & 4.38 \(\pm\) 0.08 \({}^{\text{b}}\) \\ \hline
**apple fibre** & 69.08 \(\pm\) 0.26 \({}^{\text{f}}\) & 8.05 \(\pm\) 0.11 \({}^{\text{a}}\) & 24.29 \(\pm\) 0.25 \({}^{\text{f}}\) \\ \hline
**apple pomace** & 57.35 \(\pm\) 0.71 \({}^{\text{e}}\) & 9.22 \(\pm\) 0.22 \({}^{\text{c}}\) & 21.81 \(\pm\) 0.21 \({}^{\text{e}}\) \\ \hline
**currant fibre** & 48.18 \(\pm\) 1.11 \({}^{\text{d}}\) & 14.41 \(\pm\) 0.43 \({}^{\text{f}}\) & 5.37 \(\pm\) 0.11 \({}^{\text{d}}\) \\ \hline
**currant pomace** & 37.71 \(\pm\) 0.31 \({}^{\text{b}}\) & 11.60 \(\pm\) 0.27 \({}^{\text{d}}\) & 3.91 \(\pm\) 0.15 \({}^{\text{a}}\) \\ \hline \hline \end{tabular} The same letters next to the values \({}^{\text{a}-\text{b}}\) indicate the absence of statistically significant differences (\(p<0.05\)).  
\end{table} 
Table 4: \(L^{\star}\), \(a^{\star}\), \(b^{\star}\) colour parameters for the tested fibres and fruit pomace. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample** & \begin{tabular}{c} **Density** \\ **(g/cm\({}^{3}\))** \\ \end{tabular} & \
\begin{tabular}{c} **Bulk Density Loc** \\ **(g/cm\({}^{3}\))** \\ \end{tabular} &
\begin{tabular}{c} **Bulk Density** \\ **Shaken (g/cm\({}^{3}\))** \\ \end{tabular} & **Hausner Ratio** & **Carr’s Index** \\ \hline
**chokeberry fibre** & 1.3669 \(\pm\) 0.0014 \({}^{\text{c}}\) & 0.4537 \(\pm\) 0.0059 \({}^{\text{b}}\) & 0.5427 \(\pm\) 0.0064 \({}^{\text{b}}\) & 1.1964 \(\pm\) 0.0208 \({}^{\text{ab}}\) & 16.40 \(\pm\) 1.44 \({}^{\text{ab}}\) \\
**apple fibre** & 1.3747 \(\pm\) 0.0014 \({}^{\text{c}}\) & 0.5146 \(\pm\) 0.0155 \({}^{\text{c}}\) & 0.6225 \(\pm\) 0.0005 \({}^{\text{c}}\) & 1.2104 \(\pm\) 0.0371 \({}^{\text{c}}\) & 17.33 \(\pm\) 2.57 \({}^{\text{b}}\) \\
**currant fibre** & 1.4671 \(\pm\) 0.0037 \({}^{\text{f}}\) & 0.4822 \(\pm\) 0.0105 \({}^{\text{b}}\) & 0.5572 \(\pm\) 0.0061 \({}^{\text{b}}\) & 1.1557 \(\pm\) 0.0134 \({}^{\text{ab}}\) & 13.47 \(\pm\) 1.01 \({}^{\text{ab}}\) \\
**chokeberry** & 1.3463 \(\pm\) 0.0029 \({}^{\text{a}}\) & 0.5261 \(\pm\) 0.0050 \({}^{\text{c}}\) & 0.6293 \(\pm\) 0.0003 \({}^{\text{c}}\) & 1.1962 \(\pm\) 0.0057 \({}^{\text{ab}}\) & 16.40 \(\pm\) 0.40 \({}^{\text{ab}}\) \\
**opmace** & 1.4219 \(\pm\) 0.0026 \({}^{\text{d}}\) & 0.4620 \(\pm\) 0.0155 \({}^{\text{b}}\) & 0.5447 \(\pm\) 0.0113 \({}^{\text{b}}\) & 1.1795 \(\pm\) 0.0202 \({}^{\text{ab}}\) & 15.20 \(\pm\) 1.44 \({}^{\text{ab}}\) \\
**currant pomace** & 1.4371 \(\pm\) 0.0010 \({}^{\text{de}}\) & 0.4203 \(\pm\) 0.0053 \({}^{\text{a}}\) & 0.4813 \(\pm\) 0.0032 \({}^{\text{a}}\) & 1.1453 \(\pm\) 0.0213 \({}^{\text{a}}\) & 12.66 \(\pm\) 1.61 \({}^{\text{a}}\) \\ \hline \hline \end{tabular} The same letters next to the values \({}^{\text{a}-\text{b}}\) indicate the absence of statistically significant differences (\(p<0.05\)).  
\end{table} 
Table 5: Apparent density, bulk loose density (\(pL\)), bulk shaken density (\(pT\)), Hausner ratio (HR) and Carr’s index (CI) of selected pomace and fibres. Chokeberry fibre had the lowest value of bulk density, which, in the loose state, was equal to 0.4537 g/cm\({}^{3}\), while in the shaken state, the shook condition was 0.5427 g/cm\({}^{3}\). Statistical analysis showed no statistically significant differences between chokeberry and currant's loose and bulk fibre density. The chokeberry pomace had the highest bulk density, which, in the loose state, was 0.5261 g/cm\({}^{3}\); after shaking, it was 0.6293 g/cm\({}^{3}\).