Figure 1: Schematic representation of the ion exchange column, where (1) container for feed solution; (2) peristaltic pump; (3) ion exchange resin
Table 1: Chemical sample used in this work
Models |
Parameters |
Correlations |
Freundlich |
kF (mg/g) |
27.0 ± 1.5 |
|
nF |
0.35 ± 0.02 |
R2 |
0.9982 |
|
Langmuir |
qm |
2102.8 ± 726729.5 |
|
kL (mL/mg) R2 |
0.005 ± 1.889 |
0.6799 |
||
Sips |
qmS (mg/g) |
27.4 ± 2.2 |
|
kS (mL/mg) |
2.2 ± 0.4 |
|
mS |
3.8 ± 0.1 |
|
R2 |
0.9999 |
Table 2: Equilibrium parameters obtained by the fittings of the isotherm models using ion exchange with Tanex resin at 25.0 ± 0.1 °C
Analysis |
Solution A* |
Solution B** |
Catechin (g/L) |
0.62 ± 0.01 |
0.62 ± 0.01 |
Vitamin C (mg/100g) |
NR |
147 ± 5 |
pH |
5.8 ± 0.0 |
3.1 ± 0.1 |
°Brix |
0.0 |
11.0 ± 0.1 |
Acidity (g/100 g citric acid) |
NR |
0.20 ± 0.00 |
Table 3: Chemical and physico-chemical analyzes of solutions A and B before ion exchange
Analyzes |
Cashew apple juice 1 |
Cashew apple juice 2 |
Condensed tannins (mg/100 g) |
15 ± 1 |
115 ± 1 |
Vitamin C (mg/100 g) |
185 ± 6 |
156 ± 5 |
pH |
4.72 ± 0.01 |
4.21 ± 0.02 |
°Brix |
11.6 ± 0.1 |
11.4 ± 0.1 |
Acidity (g/100 g citric acid) |
0.30 ± 0.05 |
0.35 ± 0.01 |
Table 4: Chemical and physico-chemical analyzes of cashew apple juice of different batches before ion exchange in fixed-bed column
Figure 1: Schematic representation of the ion exchange column, where (1) container for feed solution; (2) peristaltic pump; (3) ion exchange resin
Figure 2: Equilibrium isotherms for the removal of condensed tannins in cashew apple juice by ion exchange with the Tanex resin and fitted isotherms using the Freundlich, Langmuir and Sips models
Figure 3: Removal percentage and breakthrough curve for the adsorption of catechin from solution A in a fixed-bed column packed with Tanex resin, as a function of time
Figure 4: Breakthrough curves for catechin, vitamin C and °Brix using solution B in a fixed-bed column packed with Tanex resin as a function of time
Figure 5: Breakthrough curves for acidity using solution B in a fixed-bed column packed with Tanex resin, as a function of time
Figure 6: Breakthrough curves for pH using solution B in a fixed-bed column packed with Tanex resin, as a function of time
Figure 7: Breakthrough curves for tannins, vitamin C and °Brix in cashew apple juice 1 (J1) and 2 (J2), in a fixed-bed column packed with Tanex resin, as a function of time
Figure 8: Breakthrough curves for acidity in both juices J1 (a) and J2 (b), in a fixed-bed column packed with Tanex resin, as a function of time
Figure 9: Breakthrough curves for pH in both juices J1 (a) and J2 (b), in a fixed-bed column packed with Tanex resin, as a function of time
Tables at a glance
Figures at a glance