Enrichment of α-lactalbumin in whey permeate solution by a semi-batch foaming process

Application of a foam separation technique was evaluated in concentrating proteins from a whey permeate solution, which is considered a low-value effluent in the dairy industry. This was performed in a 75 mm diameter, 530 mm long glass column fitted with a stainless steel sparger that bubbled air through the system. It was possible to produce an enrichment protein fraction with a few times higher concentration and a residual solution with a significantly smaller concentration compared to that in the original feed. Concentration of proteins in whey permeate was performed with undiluted as well as diluted feed solution and it is shown that higher enrichment (about ten times) is achievable if the feed solution is diluted two times before foam separation. However, this resulted in an increase in residual protein concentration with reduced percentage recovery