title: Distribution of protein oxidation products in the proteome of thermally processed milk.
abstract: During thermal milk processing, severe oxidation can occur, which alters the technological and physiological properties of the milk proteins. Due to differences in composition and physicochemical properties, it can be expected that the particular milk proteins are differently affected by oxidative damage. Therefore, the protein-specific distribution of oxidation products in the heated milk proteome was investigated. Raw and heated milk samples were separated by one-dimensional gel electrophoresis. Protein oxidation was visualized by Western blot after derivatization of protein carbonyls with 2,4-dinitrophenylhydrazine. Thus, α-lactalbumin displayed enhanced oxidation compared to β-lactoglobulin, despite its lower concentration in milk. Highly selective oxidation was detected for a previously unassigned minor milk protein. The protein was identified by its peptide mass fingerprint as a variant of α(S1)-casein (α(S1)-casein*). Similar oxidation patterns were observed in several commercial milk products.
authors: Department of Chemistry and Pharmacy, Food Chemistry, Emil Fischer Center, University of Erlangen-Nuremberg, Schuhstrasse 19, 91052 Erlangen, Germany.
authors: Bianca
authors: B
authors: Meyer
authors: Florian
authors: F
authors: Baum
authors: Gregor
authors: G
authors: Vollmer
authors: Monika
authors: M
authors: Pischetsrieder
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D005511:Food Handling / Q000379:methods*; D006358:Hot Temperature; D007768:Lactalbumin / Q000032:analysis / Q000737:chemistry; D007782:Lactoglobulins / Q000032:analysis / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010449:Peptide Mapping; D010659:Phenylhydrazines
chemical_list: D007782:Lactoglobulins; D008894:Milk Proteins; D010659:Phenylhydrazines; C004787:2,4-dinitrophenylhydrazine; D007768:Lactalbumin