A study of the separation of proteins from multicomponent mixtures by a semi-batch foaming process

Foam fractionation offers an attractive method of separating:concentrating proteins (or their mixtures) from dilute solutions which are typical of man y dairy, food acid biological process streams. Experiments were conducted t o obtain the values of the average bubble size, gas holdup, interfacial are a, the bulk phase concentration and the heat of desorption (which determine s the concentration of adsorbed components) in the liquid solution using a 75 mm diameter, 530 mm long glass column fitted with a stainless steel spar ger For bubble generation. The mass transfer coefficient for Bovine Serum A lbumin (BSA), X,was determined from the analysis of the concentration of fo am and feed at different times using the above mentioned parameters. The va lues vary with the feed concentration, i.e. K= 4.34 x 10(-6) mol cal(-1) cm (-2)s(-1) at 60 mg 1(-1) and K= 3.62 x 10(-6) at 25 mg 1-(1). The separatio n performance, expressed as enrichment ratio. selectivity and percentage re covery, was investigated for a binary and ternary protein mixtures of BSA, cc-lactalbumin and Lactoferrin. The effects of the operating factors, i.e. air flow rate, initial feed protein concentration ratio, hubble size and so lution pH on separation performance were examined. The results provided som e guidelines in producing a fraction. enriched in the target protein lactof errin, from its mixture with other proteins. (C) 2001 Elsevier Science B.V. All rights reserved.