Foam Fractionation of á-lactalbumin and â-lactoglobulin from Whey Solution

Abstract

Whey, a byproduct of cheese production, is often considered a waste stream and typicallytransported out of dairy plant for a per volume charge. One possible method to reduce the wastevolume and disposal cost is to concentrate whey by foam fractionation and potentially produce avaluable co-product, a concentrated whey protein solution. Foam fractionation is an adsorptivebubble separation method that is based on the hydrophobic/ hydrophilic properties of proteins. Inthis study, foam fractionation was evaluated for the concentration of whey proteins specifically -lactalbumin and -lactoglobulin from a dilute whey protein isolate (WPI) solution. The effects of initialwhey protein concentration (0.075 and 0.15 mg/mL), pH (3.8-5.5), and superficial gas velocity (0.85and 0.95 cm/sec) on protein enrichment and recovery were examined. Higher enrichment wasachieved with the lower initial protein concentration (0.075 mg/mL), and at pH values that werearound to the isoelectric points (pI) of -lactalbumin and -lactoglobulin (pH 3.8, 4.2, 4.5, and 5.2).The higher superficial gas velocity enhanced the amount of proteins recovered from the dilutesolution, but with a decrease in the enrichment.