ARS | Publication request: Pilot-scale fractionation of whey proteins with supercritical CO2

Submitted to: UJNR Food & Agricultural Panel Abstracts
Publication Type: Proceedings
Publication Acceptance Date: August 18, 2008
Publication Date: August 24, 2008
Citation: Bonnaillie, L., Tomasula, P.M. 2008. Pilot-scale fractionation of whey proteins with supercritical CO2. In: US - Japan Proceedings. August 24-28, 2008. p. 120-121.

Technical Abstract: A new pilot-scale process is being developed and optimized for the separation of whey proteins into two enriched, highly functional fractions that are free of contaminants. The fractionation of whey protein isolate (WPI), which contains approximately 32% alpha-lactalbumin (alpha-LA) and 61% beta-lactoglobulin (beta-LG), was performed in an environmentally friendly way using supercritical carbon dioxide (SCO2) as an acid for the production of both alpha-LA-enriched and beta-LG-enriched protein fractions from aqueous solutions containing up to 10% (w/w) of WPI. Simulation of the WPI fractionation was first conducted using hydrochloric acid (HCl) to determine the optimal processing parameters for the SCO2 fractionation process. The fractionation kinetics of WPI with SCO2 were found to depend on CO2 pressure, run-time, pH, temperature, WPI concentration and gas-dissolution rate. Over the CO2 pressure range studied (50-2000 PSI), the optimized liquid and aggregate fractions contained up to 85% beta-LG and up to 69% alpha-LA, respectively. In this presentation, we compare the mechanisms and kinetics of the HCl- and SCO2-aggregation of alpha-LA, analyze the quality of the protein fractions produced as a function of the processing parameters, and discuss challenges encountered before further utilization of the SCO2 technology.