BATCH FOAM RECOVERY OF SPORAMIN FROM SWEET-POTATO

The major sweet potato root protein, sporamin (which comprises about 8 0-90% of the total protein mass in the sweet potato) easily foams in a bubble/foam-fractionation column using air as the carrier gas. Contro l of that foam fractionation process is readily achieved by adjusting two variables bulk solution pH and gas superficial velocity. Varying t hese parameters has an important role in the recovery of sporamin in t he foam. Changes in the pH of the bulk solution can control the partit ioning of sporamin in the foam phase from that in the bulk phase. A ch ange in pH will also affect the amount of foam generated. The pH varie d between 2.0 and 10.0 and the air superficial velocities (V-0) ranged between 1.5 and 4.3 cm/s. It was observed in these ranges that, as th e pH increased, the total foamate volume decreased, but the foamate pr otein (mainly sporamin) concentration increased. On the other hand, th e total foamate volume increased significantly as the air superficial velocity increased, but the foamate concentration decreased slightly. The minimum residual protein concentration occurred at pH 3.0 and V-0 = 1.5 cm/s. On the other hand, the maximum protein mass recovery occur red at pH 3.0 and at V-0 = 4.3 cm/s.