Abstract
Betacyanin is the red-violet pigment possesses potent antiradical and antioxidant properties. Globally, natural colorants have gained much interest than synthetic colours due to their adverse ill effects. The study aimed to assess membrane technology for the concentration of betacyanin pigment from cactus pear employing forward osmosis. The effect of process parameters such as feed and osmotic agent solution (OAS) flowrate and temperature on betacyanin concentration was investigated using factorial design. Maximum concentration of betacyanin was obtained with 150 mL/min feed flowrate, 50 °C feed temperature, 150 mL/min OAS flowrate and 50 °C OAS temperature. Further, sodium chloride was the best OAS that concentrated betacyanin from 898 to 1325 mg/L with a transmembrane flux of 1.13 L/m(2) h. Physico-chemical characteristics imply high retention of antioxidant activity and other nutrients during concentration process. The results revealed the suitability of forward osmosis for the concentration of betacyanin from Opuntia ficus-indica using cellulose acetate membrane.