# Elderberry Concentrate Juice Industrial By-Products Characterization and Valorisation
## 3 Results and Discussion
### By-Products Characterization
As a result of the reverse phase extraction of the HMWM from the retained material, a hydrophobic fraction which accounted for 44% of the total HMWM mass was obtained. \begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & \multicolumn{1}{c}{\multirow{2}{*}{\(\boldsymbol{\eta\%}\) 1}} & \multicolumn{1}{c}{\multirow{2}{*}{**Mannitol**}} & \multicolumn{3}{c}{**(mol\%)**} & \multicolumn{3}{c}{**Total**} \\ \cline{3-11}  & & & & & & & & & **Sugars** & **Mannitol** \\ \cline{2-11}  & **Rha** & **Fuc** & **Ara** & **Xyl** & **Man** & **Gal** & **Glc** & **Fru** & **GaAl** & **(\(\boldsymbol{\mu\text{g}\cdot\text{mg}^{-1}}\))** & **(\(\boldsymbol{\mu\text{g}\cdot\text{mg}^{-1}}\))** \\ \hline
**Pomace** & & & & & & & & & & & & \\ Total sugars & & 0.5 & 0.2 & 4 & 24 & 4 & 3 & 50 & 1 & 14 & 496 \(\pm\) 6 & \\ Free sugars & & & & & & & & & & & 152 \(\pm\) 0.01 & \\
**Retentate** & & & & & & & & & & & & \\ WSM & 48 & & & & & & & & & & & \\ Total sugars & & 2 & 0.1 & 3 & 6 & 11 & 4 & 47 & 27 & 685 \(\pm\) 34 & 9 \(\pm\) 0.03 \\ Free sugars & & 4 & 0.4 & 4 & 5 & & 1 & 80 & 8 & 466 \(\pm\) 0.05 & \\ LMWM & 38 (77) & 1 & & 2 & 3 & 1 & 79 & 14 & 317 \(\pm\) 0.2 & 10 \(\pm\) 0.01 \\ HMWM & 7 (14) & 6 & & 12 & 10 & 4 & 13 & 1 & 4 & 47 & 526 \(\pm\) 36 & 4 \(\pm\) 0.01 \\ Hydrophilic material & 1.3 (38) & 8 & 1 & 8 & 4 & 1 & 16 & 3 & 61 & 719 \(\pm\) 12 & \\ Hydrophobic material & 1.5 (44) & 3 & & 8 & 23 & & 7 & 44 & & 15 & 201 \(\pm\) 0.05 & \\ Washing & 0.52 & & & & & & & & & & & \\ Total sugars & & 2 & 0.1 & 2 & 7 & 16 & 2 & 39 & 31 & 639 \(\pm\) 11 & 8 \(\pm\) 0.03 \\ Free sugars & & & 5 & 0.2 & 6 & 19 & & 7 & 63 & & 182 \(\pm\) 0.02 & \\ WIM & 50 & & & & & & & & & & & \\ Total sugars & & 1 & & 3 & 12 & 9 & 10 & 46 & 8 & 256 \(\pm\) 6 & \\ \hline \hline \end{tabular}  
* Values between brackets correspond to yields calculated in water soluble material or HMWM dry weight basis. WSM—Water soluble material; LMWM—Low molecular weight Material; HMWM—High molecular weight material; WIM—Water insoluble material. Relative standard deviation of sugars mol% is less than 5% for the major sugars.  
\end{table} 
Table 2: Sugar composition and mannitol of elderberry pomace and reetentate fractions. It contained only 20% of sugars, mainly glucose (65%), xylose (28%), and rhamnose (3%), possibly associated with polymerized anthocyanins containing cyanidin 3-glucoside, cyanidin 3-sambubioside and cyanidin 3-rutinoside monomers. This hydrophobic fraction also contained galacturonic acid, arabinose, and galactose, which could be due to the presence of methyl esterified galacturonic acid, allowing the retention of these uncharged polysaccharidesides in the C18 column, or arabian complexes with polyphenols [34]. On the contrary, the hydrophilic fraction, accounting for 38% of total HMWM mass, had 79% of carbohydrates rich in galacturonic acid (61%), consistent with the enrichment of pectin polysaccharides branched by chains of galactose (16%) and arabinose (8%). This was confirmed by the results of a methylation analysis (Table 3). \begin{table}
\begin{tabular}{l c c} \hline \hline  & **Glycosidic-Linkage** & **\%mol** \\ \hline t-Rhap & & 3.3 \\
2-Rhap & & 5.8 \\
2,4-Rhap & & 3.5 \\
2,3-Rhap & & 1.5 \\
2,3,4-Rhap & & 1.6 \\
4-Fucp & Total Rhap & 15.8 (19.5) & 1.2 \\  & Total Fucp & 1.2 (2.4) & 6.2 \\ t-Araf & & 0.7 \\
3-Araf & & 2.7 \\
5-Araf & & 1.1 \\
4-Arap & & 1.6 \\
3,5-Araf & & 0.5 \\
2,3-Arap & & 6.4 \\
2,3,5-Araf & & 2.0 \\  & Total Ara & 21.3 (19.5) & 3.7 \\ t-Xylp & & 0.5 \\
2-Xylp & & 0.5 \\
4-Xylp & & 6.2 \\
2,4-Xylp & & 2.9 \\  & Total Xylp & 13.2 (9.8) & \\ t-Manp & & 0.3 \\
3,4-Manp & & 1.7 \\
2,6-Manp & & 0.6 \\  & Total Manp & 2.7 (2.4) & \\ t-Galp & & 6.8 \\
2-Galp & & 0.5 \\
4-Galp & & 1.0 \\
3-Galp & & 0.5 \\
6-Galp & & 4.2 \\
2,4-Galp & & 2.6 \\
3,6-Galp & & 7.0 \\
2,3,4-Galp & & 1.1 \\
2,3,4,6-Galp & & 1.3 \\  & Total Galp & 25.0 (39.0) & 2.8 \\ t-GalpA & & 2.5 \\
4-GalpA & & 1.0 \\
2,4-GalpA & & 6.3 \\ t-GlcpA & & 7.3 \\
3,4-GlcpA & & 2.1 \\  & Total GlcpA & 9.3 & \\ \hline \hline \end{tabular}
\end{table}