Jump to Main Content
Enrichment and Purification of Casein Glycomacropeptide from Whey Protein Isolate Using Supercritical Carbon Dioxide Processing and Membrane Ultrafiltration
- Bonnaillie, Laetitia M., Qi, Phoebe, Wickham, Edward, Tomasula, Peggy M.
- Foods 2014 v.3 no.1 pp. 94
- acid deposition, beta-lactoglobulin, beverages, carbon dioxide, casein, functional properties, ingredients, lactalbumin, pH, supercritical fluid extraction, temperature, ultrafiltration, whey, whey protein concentrate, whey protein isolate
- Whey protein concentrates (WPC) and isolates (WPI), comprised mainly of β-lactoglobulin (β-LG), α-lactalbumin (α-LA) and casein glycomacropeptide (GMP), are added to foods to boost nutritional and functional properties. Supercritical carbon dioxide (SCO₂) has been shown to effectively fractionate WPC and WPI to obtain enriched fractions of α-LA and β-LG, thus creating new whey ingredients that exploit the properties of the individual component proteins. In this study, we used SCO₂ to further fractionate WPI via acid precipitation of α-LA, β-LG and the minor whey proteins to obtain GMP-enriched solutions. The process was optimized and α-LA precipitation maximized at low pH and a temperature (T) ≥65 °C, where β-LG with 84% purity and GMP with 58% purity were obtained, after ultrafiltration and diafiltration to separate β-LG from the GMP solution. At 70 °C, β-LG also precipitated with α-LA, leaving a GMP-rich solution with up to 94% purity after ultrafiltration. The different protein fractions produced with the SCO₂ process will permit the design of new foods and beverages to target specific nutritional needs.