Background: Forward osmosis is a sustainable membrane process employed for concentrating
thermo-sensitive compounds to minimize storage and transportation costs with improved shelf life.
Objective: In this study, the intervention of high molecular weight osmotic agents in the concentration
of Opuntia betacyanin using forward osmosis was studied. Furthermore, the statistical model was used
to estimate the probabilistic behavior of the forward osmosis process during concentration.
Methods: By using 2k-full factor analysis, the hydrodynamic variables, such as flow rate (50 and 150
mL/min) and temperature (20 and 50ºC) of the feed solution and osmotic agent solution (OAS) were selected.
The study focused on inquiring and developing a statistically significant mathematical model using
four independent variables on transmembrane flux, concentration factor and concentrate recovery.
Results: Betacyanin feed flow rate of 50 mL/min at 28ºC, and OAS flow rate of 150 mL/min at 50ºC
were determined as optimal conditions with a 2.5-fold increase in total soluble solids for a processing
time of 4 h. Furthermore, forward osmosis enhanced the betacyanin concentration from 898 to 1004
mg/L and 98.7% recovery with 0.40 L/m2h transmembrane flux with comparable improvement in its
physicochemical characteristics. The lower p-value of the main effects on the responses validated the
significance of the process parameters on betacyanin concentration.
Conclusion: The study suggested that a high molecular weight sucrose could be used as an osmotic
agent for the concentration of Opuntia betacyanin during forward osmosis.