ABSTRACT
An aqueous two-phase system (ATPS) in combination with macro- and micro-extractors was used for polyphenol extraction from a model solution (gallic acid) and three real samples (red and white wine, and orange juice). The objective of the present study was to apply a mathematical model that successfully describes and predicts performances of macro- and micro-extractors. The micro-extractor system was selected as the most suitable for the polyphenol extraction because the same extraction efficiency was obtained for two levels of magnitude shorter residence time compared to the macro-extractor. Based on good agreement between model predictions and experimental results, the obtained simulations could be used for further process optimization and improvement.
Nomenclature
A | = | absorbance, - |
c | = | concentration, mol dm−3 |
D | = | molecular diffusion coefficient, m2 s−1 |
k | = | phase equilibrium rate constant, s−1 |
Kp | = | partition coefficient for polyphenols in aqueous two-phase system, - |
L | = | microchannel length, m |
m | = | mass, g |
m* | = | equilibrium mass, g |
n | = | number of experimental data, - |
q | = | mass flow rate, g s−1 |
qV | = | volumetric flow rate, dm3 s−1 |
T | = | temperature, °C |
t | = | time, s |
v | = | polyphenols transfer rate, g dm−3 s−1 |
V | = | volume, dm3 |
Vm | = | molar volume, dm3 mol−1 |
w | = | mass fraction, g g−1 |
W | = | microchannel width, m |
w* | = | equilibrium mass fraction, g g−1 |
x | = | coordinate in microchannel length |
y | = | coordinate in microchannel width |
γ | = | mass concentration, g dm−3 |
ε | = | extraction efficiency, % |
ξ | = | dimensionless independent variable, - |
ψ | = | dimensionless independent variable, - |
η | = | dynamic viscosity, g m−1 s−1 |
τ | = | residence time, s |
AMS | = | ammonium sulphate |
ATPS | = | aqueous two-phase system |
EVOP | = | evolutionary operation |
df | = | degree of freedom |
PEG | = | polyethylene glycol |
TP | = | total phenols |
RMSE | = | root mean square error |
R2 | = | Pearson correlation coefficient |
R | = | rafinate |
E | = | extract |
Conflict of interest
The authors declare that there is no conflict of interest regarding the publication of this paper.