title: Digestibility and allergenicity assessment of enzymatically crosslinked beta-casein.
abstract: Crosslinking enzymes are frequently used in bioprocessing of dairy products. The aim of this study was to examine the effects of enzymatic crosslinking on IgE binding, allergenicity and digestion stability of beta-casein (CN). beta-CN was crosslinked by transglutaminase, tyrosinase, mushroom tyrosinase/caffeic acid and laccase/caffeic acid. The IgE binding to beta-CN was compared in vitro by CAP inhibition assay, ELISA inhibition as well as ex vivo by basophil activation assay. Crosslinked CNs were digested by simulated gastric fluid for 15 and 60 min and obtained digests analyzed for their ability to inhibit IgE binding by CAP inhibition assay and SDS-PAGE. The ability of crosslinked CNs to activate basophils was significantly reduced in seven patients in the case of CN crosslinked by laccase and moderately reduced in the case of tyrosinase/caffeic acid crosslinked CN (in two cow's milk allergy patients tested with different allergen concentrations). The response to various crosslinked CNs differed individually among patients' sera tested by ELISA inhibition assay. The presence of caffeic acid hampered digestion by pepsin, and this effect was most pronounced for the tyrosinase/caffeic acid crosslinked CN. The laccase/caffeic acid and mushroom tyrosinase/caffeic acid had the highest potential in mitigating IgE binding and allergenicity of the beta-CN out of all investigated enzymes. The presence of a small phenolic compound also increased digestion stability of beta-CN.
authors.affiliation: Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Belgrade, Serbia.
authors.forename: Dragana
authors.initials: D
authors.lastname: Stanic
authors.forename: Evanthia
authors.initials: E
authors.lastname: Monogioudi
authors.forename: Ercili
authors.initials: E
authors.lastname: Dilek
authors.forename: Jelena
authors.initials: J
authors.lastname: Radosavljevic
authors.forename: Marina
authors.initials: M
authors.lastname: Atanaskovic-Markovic
authors.forename: Olga
authors.initials: O
authors.lastname: Vuckovic
authors.forename: Lantto
authors.initials: L
authors.lastname: Raija
authors.forename: Maija
authors.initials: M
authors.lastname: Mattinen
authors.forename: Johanna
authors.initials: J
authors.lastname: Buchert
authors.forename: Tanja
authors.initials: T
authors.lastname: Cirkovic Velickovic
mesh_terms: D000293:Adolescent; D000485:Allergens / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D015549:Basophil Degranulation Test; D002109:Caffeic Acids / Q000378:metabolism; D002364:Caseins / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism*; D002675:Child, Preschool; D004063:Digestion; D004797:Enzyme-Linked Immunosorbent Assay; D005511:Food Handling / Q000379:methods; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology / Q000378:metabolism; D007700:Kinetics; D042845:Laccase / Q000378:metabolism; D016269:Milk Hypersensitivity / Q000097:blood / Q000276:immunology*; D014442:Monophenol Monooxygenase / Q000378:metabolism; D058105:Polymerization; D011492:Protein Hydrolysates / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D011503:Transglutaminases / Q000378:metabolism
chemical_list: D000485:Allergens; D002109:Caffeic Acids; D002364:Caseins; D011492:Protein Hydrolysates; D007073:Immunoglobulin E; D042845:Laccase; D014442:Monophenol Monooxygenase; D011503:Transglutaminases; C040048:caffeic acid