Protein thiols undergo reversible and irreversible oxidation during chill storage of ground beef as detected by 4,4'-dithiodipyridine.
Quantification of protein thiols and disulfides in ground beef during storage under high-oxygen atmosphere at 4 °C was performed by thiol detection using 4,4'-dithiodipyridine (4-DPS) before and after disulfide reduction using sodium borohydride. Two independent storage trials were performed, and in trial 1, only reversible thiol oxidation was observed (thiol loss was 30%). In trial 2, irreversible thiol oxidation occurred during the first days of storage, while further loss of thiols was caused by reversible disulfide formation (thiol loss was 33%, of which ca. half was lost because of irreversible oxidation). The results were compared to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of cross-linked myosin heavy chain formed by disulfide bonding. Both methods confirmed increasing disulfide formation because of thiol oxidation in meat during storage, but the 4-DPS method showed higher disulfide percentages than the SDS-PAGE method (22.2 ± 0.3% and 8.5 ± 1.2%, respectively). The 4-DPS assay provides an accurate method to evaluate the thiol-disulfide redox state in meat.
Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO) , Brusselsesteenweg 370, 9090 Melle, Belgium.
Tine
T
Rysman
Sisse
S
Jongberg
Geert
G
Van Royen
Stephanie
S
Van Weyenberg
Stefaan
S
De Smet
Marianne N
MN
Lund
D000818:Animals; D002417:Cattle; D003080:Cold Temperature; D004220:Disulfides / Q000737:chemistry; D061353:Food Storage; D008460:Meat / Q000032:analysis*; D010084:Oxidation-Reduction; D011506:Proteins / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D004220:Disulfides; D011506:Proteins; D011725:Pyridines; D013438:Sulfhydryl Compounds; C007542:4,4'-dipyridyl disulfide
4,4′-dithiodipyridine; disulfides; meat proteins; protein oxidation; thiols