Effect of a natural contaminant on foam fractionation of bromelain

Foam fractionation is a simple, inexpensive method for separating and purif ying proteins. Typically, a dilute bromelain solution with a pH ranging fro m 2.0 to 7.0 foams very well when bubbles are introduced into a foam fracti onation column. It was observed, however, that the dilute enzyme solution o nly foamed between approximately pH 2.0 and 3.0 when the inner wall of the fractionation column was coated with a natural contaminant (okra residue). We studied the separation ratio and the protein mass recovery to explore th e effect of a natural antifoaming agent on the foam fractionation of a dilu te bromelain solution. The control variables used in this process were the initial bulk solution pH, which ranged from 2.0 to 7.0, and the superficial air velocity, which varied between 1.7 and 6.2 cm/s.