title: Toward a better determination of dairy powders surface composition through XPS matrices development.
abstract: The surface composition of dairy powders prepared by mixing various amounts of micellar casein (MC), whey proteins isolate (WPI), lactose, and anhydrous milk fat (AMF) was investigated by XPS measurements. The use of matrices are generally accepted to transform surface atomic composition (i.e., C, O, N contents) into surface component composition (i.e., lactose, proteins, lipids). These atomic-based matrices were revisited and two new matrices based on the surface bond composition were developed. Surface compositions obtained from atomic and bond-based matrices were compared. A successful matrix allowing good correlations between XPS predicted and theoretical surface composition for powders free from fat was identified. Nevertheless, samples containing milk fat were found to present a possible segregation of components owing to the AMF overrepresentation on the surface. Supplementary analyses (FTIR, SEM) were carried out in order to investigate the homogeneity of the mixtures.
authors.affiliation: Université de Lorraine, Laboratoire d'Ingénierie des Biomolécules (LIBio), 2 av de la Foret de Haye, TSA 40602, 54518 Vandœuvre lès Nancy, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Nikolova
authors.affiliation: Université de Lorraine, Laboratoire d'Ingénierie des Biomolécules (LIBio), 2 av de la Foret de Haye, TSA 40602, 54518 Vandœuvre lès Nancy, France.
authors.forename: J
authors.initials: J
authors.lastname: Petit
authors.affiliation: Nestec PTC Konolfingen, Nestlé Strasse 3, 3510 Konolfingen, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: Sanders
authors.affiliation: Nestec PTC Konolfingen, Nestlé Strasse 3, 3510 Konolfingen, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Gianfrancesco
authors.affiliation: Université de Lorraine, Laboratoire d'Ingénierie des Biomolécules (LIBio), 2 av de la Foret de Haye, TSA 40602, 54518 Vandœuvre lès Nancy, France.
authors.forename: J
authors.initials: J
authors.lastname: Scher
authors.affiliation: Université de Lorraine, Laboratoire d'Ingénierie des Biomolécules (LIBio), 2 av de la Foret de Haye, TSA 40602, 54518 Vandœuvre lès Nancy, France. Electronic address: claire.gaiani@univ-lorraine.fr.
authors.forename: C
authors.initials: C
authors.lastname: Gaiani
mesh_terms: D000818:Animals; D002364:Caseins / Q000737:chemistry*; D003611:Dairy Products / Q000032:analysis*; D004041:Dietary Fats / Q000032:analysis*; D007785:Lactose / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D011208:Powders; D013499:Surface Properties; D000067816:Whey Proteins
chemical_list: D002364:Caseins; D004041:Dietary Fats; D008894:Milk Proteins; D011208:Powders; D000067816:Whey Proteins; D007785:Lactose
keywords: Dairy powders; FTIR; Matrix development; Surface composition; XPS