Cross-Linking of Whey Proteins by Enzymatic Oxidation

• Published in: Journal of agricultural and food chemistry Vol. 46; no. 4; pp. 1326 - 1333
• Main Authors: Otte, Jeanette, Qvist, Karsten Bruun
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-04-1998
• Subjects: ACCA; AMINE OXIDASE; AMINE OXIDASE (FLAVIN-CONTAINING); Animal, plant, fungal and microbial proteins, edible seaweeds and food yeasts; Biological and medical sciences; ENZYMATIC MODIFICATION; ENZYME SPECIFICITY; Food industries; Fundamental and applied biological sciences. Psychology; GELATION; JELLIFICATION; LACCASE; MILK; MYRTACEAE; OXIDATION; PEROXIDASES; POLYMERIZATION; PROTEIN CROSS-LINKING; PROTEIN ISOLATES; PROTEINS; VISCOSITY; WHEY PROTEIN; WHEY PROTEIN ISOLATE; Viscosity; Enzyme; Gelation; Polymerization; Physical properties; Amine oxidase (flavin-containing); Enzymatic method; Peroxidases; Lactoglobulins; Lactalbumin; Substrate specificity; Oxidation; Peroxidase; Oxidoreductases; Whey protein; Comparative study; Rheological properties; Laccase
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf970743c

The applicability of enzymatic oxidation for polymerization of whey proteins [in whey protein isolate (WPI)] has been investigated, using three different oxidoreductases with different specificities (microbial peroxidase, fungal laccase, and bovine plasma monoamine oxidase) to induce oxidation. All three enzymes were able to induce formation of oligomers and polymers of whey proteins under various conditions, but their modes of action seemed to diverge, as they affected the two main whey proteins β-lactoglobulin and α-lactalbumin differently:  for example, peroxidase (in the presence of hydrogen peroxide) mainly acted on β-lactoglobulin, laccase (in the presence of chlorogenic acid) mainly worked on α-lactalbumin, and monoamine oxidase acted somewhat on both proteins. None of the oxidoreductases induced full polymerization of WPI, as opposed to cross-linking with microbial transglutaminase with a reductant present, which polymerizes the whey proteins fully. None of the oxidoreductases could induce gelling of WPI solutions with 10−20% protein. Keywords: Enzymatic; oxidation; whey proteins; cross-linking; polymerization