EFFECT OF BUBBLE VELOCITY AND PH STEP CHANGES ON THE FOAM FRACTIONATION OF SPORAMIN

Foam fractionation can be employed to concentrate and separate sporami n (ipomoein) from a sweet potato protein-water extract. In this foam f ractionation study, the bulk solution pH and the air superficial veloc ity, V-0, were the two primary control variables. It was determined th at the protein separation ratio is strongly dependent on the bulk solu tion pH, with the highest sporamin recovery occurring at pH 3. Two typ es of experiments were conducted here. The first was to hold the air s uperficial velocity constant and step down the pH in small increments, with 10 mt of foamate collected at each pH level. The second was to h old the pH constant and step up the air superficial velocity, V-0, in small increments, again with 10 mt of foamate collected at each V-0 le vel. The lowest feasible air superficial velocity generally correspond s to the maximum protein recovery at a given pH. One strategy for sepa rating beta-amylase from sporamin in the sweet potato extract is to fi rst foam the bulk solution at pH 5 to concentrate the sporamin, follow ed by foaming at pH 3 to collect the concentrated beta-amylase.