title: Effects of thermally induced denaturation on technological-functional properties of whey protein isolate-based films.
abstract: This study examined how and to what extent the degree of denaturation affected the technological-functional properties of whey protein isolate (WPI)-based coatings. It was observed that denaturation affected the material properties of WPI-coated films significantly. Surface energy decreased by approximately 20% compared with native coatings. Because the surface energy of a coating should be lower than that of the substrate, this might result in enhanced wettability characteristics between WPI-based solution and substrate surface. Water vapor barrier properties increased by about 35% and oxygen barrier properties increased by approximately 33%. However, significant differences were mainly observed between coatings made of fully native WPI and ones with a degree of denaturation of 25%. Higher degrees of denaturation did not lead to further improvement of material properties. This observation offers cost-saving potential: a major share of denatured whey proteins may be replaced by fully native ones that are not exposed to energy-intensive heat treatment. Furthermore, native WPI solutions can be produced with higher dry matter content without gelatinizing. Hence, less moisture has to be removed through drying, resulting in reduced energy consumption.
authors.affiliation: Fraunhofer-Institute for Process Engineering and Packaging IVV, Giggenhauser Strasse 35, 85354 Freising, Germany; Technische Universität München, Chair of Food Packaging Technology, Weihenstephaner Steig 22, 85354 Freising, Germany. Electronic address: markus.schmid@ivv.fraunhofer.de.
authors.forename: M
authors.initials: M
authors.lastname: Schmid
authors.affiliation: Fraunhofer-Institute for Process Engineering and Packaging IVV, Giggenhauser Strasse 35, 85354 Freising, Germany; Fulda University of Applied Sciences, Department of Food Technology, Marquardstrasse 35, 36039 Fulda, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Krimmel
authors.affiliation: Fulda University of Applied Sciences, Department of Food Technology, Marquardstrasse 35, 36039 Fulda, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Grupa
authors.affiliation: Fraunhofer-Institute for Process Engineering and Packaging IVV, Giggenhauser Strasse 35, 85354 Freising, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Noller
mesh_terms: D006863:Hydrogen-Ion Concentration; D008962:Models, Theoretical; D010100:Oxygen / Q000737:chemistry; D011489:Protein Denaturation; D012996:Solutions; D000067796:Whey / Q000737:chemistry*; D000067816:Whey Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D012996:Solutions; D000067816:Whey Proteins; D010100:Oxygen
keywords: degree of denaturation; oxygen permeability; surface energy; water vapor transmission rate; whey protein isolate