title: Relationship between oxygen concentration, shear force and protein oxidation in modified atmosphere packaged pork.
abstract: Pork loins were stored at 5°C for 14 days to investigate the effect of oxygen concentration in modified atmosphere packaging (MAP) on shear force and oxidation of lipids and proteins. The modified atmosphere contained 0 to 80% O2, 20% CO2, and balanced with N2. The results showed that shear force and thiobarbituric acid-reactive substances (TBARS) values increased with increasing oxygen concentration. Protein oxidation when measured as loss of free thiol groups, was greater in meat packaged under oxygen (20-80%). Myosin heavy chain (MHC) cross-linking, another marker of protein oxidation, was greater in MAP with 80% oxygen than 0% and 20% oxygen. Desmin degradation was not affected by the presence of oxygen, suggesting that the mechanism of oxygen-induced toughening of meat is through protein oxidation leading to cross-linking of structural proteins rather than through inactivation of proteolytic enzymes leading to reduced proteolysis.
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Bao
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland. Electronic address: per.ertbjerg@helsinki.fi.
authors.forename: Per
authors.initials: P
authors.lastname: Ertbjerg
mesh_terms: D000818:Animals; D003893:Desmin; D018857:Food Packaging / Q000379:methods*; D005519:Food Preservation; D008460:Meat / Q000032:analysis*; D010084:Oxidation-Reduction; D010100:Oxygen; D033081:Shear Strength; D013438:Sulfhydryl Compounds; D013552:Swine; D017392:Thiobarbituric Acid Reactive Substances
chemical_list: D003893:Desmin; D013438:Sulfhydryl Compounds; D017392:Thiobarbituric Acid Reactive Substances; D010100:Oxygen
keywords: Desmin; Meat tenderness; Myosin heavy chain; Protein cross-linking; Proteolysis; TBARS