title: Fractionation of whey protein isolate with supercritical carbon dioxide to produce enriched α-lactalbumin and β-lactoglobulin food ingredients.
abstract: An environmentally friendly protein fractionation process using supercritical carbon dioxide (SCO(2)) as an acid was developed to produce enriched α-lactalbumin (α-LA) and β-lactoglobulin (β-LG) fractions from whey protein isolate solutions containing from 2 to 10% WPI. This study investigated the effects of pH, temperature, WPI concentration, and residence time on the precipitation kinetics and recovery yields of individual whey proteins and the relative enrichment and composition of both protein fractions. At 5.5-34 MPa and 60-65 °C, solubilized SCO(2) decreased solution pH and induced the formation and precipitation of α-LA aggregates. Gel electrophoresis and HPLC of the enriched fractions demonstrated the production of ≥ 60% pure α-LA, and ≥ 70% pure β-LG, under various operating conditions, from WPI containing ∼57% β-LG and 21% α-LA. The enriched fractions are ready-to-use food ingredients with neutral pH, untainted by acids and contaminants.
authors.affiliation: Dairy and Functional Foods Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. bonnaillie@ars.usda.gov
authors.forename: Laetitia M
authors.initials: LM
authors.lastname: Bonnaillie
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Tomasula
mesh_terms: D002245:Carbon Dioxide; D005591:Chemical Fractionation; D011232:Chemical Precipitation; D005527:Food, Fortified; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007768:Lactalbumin / Q000032:analysis / Q000302:isolation & purification*; D007782:Lactoglobulins / Q000032:analysis / Q000302:isolation & purification*; D008894:Milk Proteins / Q000737:chemistry*; D012995:Solubility; D012996:Solutions; D013696:Temperature; D000067816:Whey Proteins
chemical_list: D007782:Lactoglobulins; D008894:Milk Proteins; D012996:Solutions; D000067816:Whey Proteins; D002245:Carbon Dioxide; D007768:Lactalbumin