title: Caseinomacropeptide behaviour in a whey protein fractionation process based on α-lactalbumin precipitation.
abstract: This work studied the behaviour of caseinomacropeptide (CMP) in a whey protein fractionation process based on the selective precipitation of α-lactalbumin (α-la) in an acid medium. Three different acids (hydrochloric, citric and lactic) and different operating conditions (protein concentration, temperature and pH) were considered to perform the precipitation step. Under the optimised precipitation conditions obtained for α-la (pH 4, 55°C, initial α-la concentration around 12 g/l) CMP presents quite similar behaviour to that observed for β-lactoglobulin (β-lg), namely remaining in the supernatant fraction. However, at a lower pH value (3.5) the amount of precipitated CMP increases up to 72% when citric acid is added. This behaviour could be due to the fact that CMP is close to its isoelectric point, which allows a supernatant fraction enriched in β-lg that is almost free from the rest of proteins in sweet whey.
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Ayoa
authors.initials: A
authors.lastname: Fernández
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Violeta
authors.initials: V
authors.lastname: Menéndez
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Riera
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Álvarez
mesh_terms: D000818:Animals; D002364:Caseins / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D011232:Chemical Precipitation; D005504:Food Analysis; D007768:Lactalbumin / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D000067816:Whey Proteins
chemical_list: D002364:Caseins; D008894:Milk Proteins; D010446:Peptide Fragments; D000067816:Whey Proteins; C065989:caseinomacropeptide; D007768:Lactalbumin