title: Determination of hydroxytryptophan isomers in gamma-irradiated egg white, chicken meat, and shrimps.
abstract: The radiation induced products of tryptophan (TRP) were determined in gamma-irradiated egg white, chicken meat and shrimps using RP-HPLC and electrochemical detection. A two-step hydrolysis with proteinase K and carboxypeptidase A was developed to release the radiation products from egg white and chicken meat and with proteinase K and pronase E from shrimps. The four hydroxytryptophan isomers (OH-Trp) were identified and quantified as radiation products in all samples. The amounts ranged between 0.02 and 1.97 mg/kg protein. A significant difference between irradiated and unirradiated samples was found for irradiation doses of more than 3 kGy for egg white and chicken meat. For shrimps no significant increase of OH-Trp isomers was measured up to a radiation dose of 5 kGy.
authors.affiliation: Universität Hamburg, Institut für Biochemie und Lebensmittelchemie. kim_kleeberg@public.uni-hamburg.de
authors.forename: K K
authors.initials: KK
authors.lastname: Kleeberg
authors.forename: B
authors.initials: B
authors.lastname: van Wickern
authors.forename: T J
authors.initials: TJ
authors.lastname: Simat
authors.forename: H
authors.initials: H
authors.lastname: Steinhart
mesh_terms: D006916:5-Hydroxytryptophan / Q000032:analysis*; D000818:Animals; D002645:Chickens; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D033364:Decapoda / Q000737:chemistry / Q000528:radiation effects*; D004529:Egg White / Q000032:analysis / Q000528:radiation effects*; D004563:Electrochemistry / Q000379:methods; D005514:Food Irradiation; D005720:Gamma Rays; D007536:Isomerism; D008460:Meat / Q000032:analysis / Q000528:radiation effects*; D012758:Shellfish / Q000032:analysis / Q000528:radiation effects*; D014364:Tryptophan / Q000737:chemistry / Q000528:radiation effects*
chemical_list: D014364:Tryptophan; D006916:5-Hydroxytryptophan