Oxidative modification of amino acids in porcine myofibrillar protein isolates exposed to three oxidizing systems

Donkeun Park, Youling L. Xiong

Research output: Contribution to journalArticlepeer-review

85 Scopus citations


Susceptibility of amino acids in myofibrillar protein isolate (MPI) exposed to three oxidizing matrixes commonly encountered in muscle foods was compared. MPI suspensions (20 mg protein/mL) in 15 mM piperazine-N,N bis(2-ethane sulphonic acid) buffer (pH 6.0) were oxidized with an iron-catalyzed oxidizing system (IOS, 0.01 mM FeCl3, 0.1 mM ascorbic acid, 0.0-10.0 mM H2O2), a lipid-oxidizing system (LOS, 0.0-10.0 mM linoleic acid, 3750 units of lipoxidase/mL), or a metmyoglobin (MetMb) oxidizing system (MOS, 0.0-0.5 mM H2O2/MetMb) for 24 h at 4 °C. Changes were quantitatively analyzed by determining amino acids on a reverse-phase liquid chromatographic (LC) system. In IOS, the amount of cysteine, methionine and tyrosine decreased (P < 0.05) with increasing [H2O2]. In LOS, only cysteine and methionine were lowered at increasing linoleic acid concentrations. In MOS, the quantity of alanine, cysteine, glycine, histidine, leucine and lysine, as well as the total amount of amino acids were significantly reduced at high concentrations of MetMb/H2O2. The results suggest that under typical meat processing conditions, iron- and metmyoglobin-catalyzed reactions play a major role in the oxidation of amino acids in muscle proteins.

Original languageEnglish
Pages (from-to)607-616
Number of pages10
JournalFood Chemistry
Issue number2
StatePublished - 2007

Bibliographical note

Funding Information:
This research was supported by a CSREES/USDA NRI grant, under Agreement Grant No. 2004-35503-14122.


  • Amino acids
  • Hydroxyl radicals
  • Metmyoglobin
  • Protein oxidation

ASJC Scopus subject areas

  • Analytical Chemistry
  • Food Science


Dive into the research topics of 'Oxidative modification of amino acids in porcine myofibrillar protein isolates exposed to three oxidizing systems'. Together they form a unique fingerprint.

Cite this