Foam Fractionation as a Means to Recover and Fractionate Bioactives

In this research, the optimum conditions for the separation of polyphenols from apple juice (AJ) and the separation of BSA from a BSA/water solution were found by looking at the enrichment ratio (ER) and recovery. A mixture of the AJ and BSA was also studied to see how the different conditions affect separation of either compound. For AJ only, maximum ER was achieved at a feed concentration of 0.00184mg/mL of polyphenols (10.9 ̊Brix), air flowrate of 10mL/min, pH of 6.03 and temperature of 4.1 ̊C. For the BSA only solution, maximum ER was achieved at a feed concentration of 2.5g/L, air flowrate of 7mL/min, pH of 5-6 and temperature either above or below 20 ̊C. For the mixture, maximum polyphenol ER was at a feed polyphenol concentration of 0.0018mg/mL, feed BSA concentration of 5g/L and a pH of 3.7. Whereas maximum BSA ER was achieved when the feed polyphenol concentration was again 0.00184mg/mL, but a minimum was seen at 5g/L BSA feed concentration and pH of 3.7. These results show that there are interactions between the polyphenol and proteins that affects the separation of compounds. The bubble size distribution and gas hold-up of the AJ and BSA solutions were then compared and the BSA solution had larger bubbles present and a greater gas hold-up, which is attributed to the greater surface activity of BSA protein. Finally basic modelling – linear regression, was performed to link the ER to the different conditions tested. The models were judged by comparing R values, the F-statistic and the p-value and all showed weak relationships between the ER and the independent variables. Further data is required to improve the model as from previous literatures these variables have been seen to contribute to adsorption, which in turn affects the ER.