Changes in the Sarcoplasmic Proteome of Beef Muscles with Differential Color Stability during Postmortem Aging

Abstract

Beef color is a muscle-specific trait, and sarcoplasmic proteome influences muscle-specific variations in beef color stability. Postmortem aging influences the color and sarcoplasmic proteome of beef muscles. Nonetheless, muscle-specific changes in sarcoplasmic proteome of beef muscles with differential color stability during aging have not been characterized yet. Therefore, our objective was to examine the changes in the sarcoplasmic proteome of 3 differentially color stable muscles from beef hindquarters during postmortem aging. (LL), (PM), and (ST) separated from 8 ( = 8) beef carcasses (24 h postmortem) were subjected to aging in vacuum packaging (2°C) for 0, 7, 14, and 21 d. On each aging day, steaks were fabricated, and allotted to refrigerated storage (2°C) under aerobic packaging. Samples for proteome analysis obtained during fabrication were frozen at –80°C. Instrumental color and metmyoglobin reducing activity were evaluated on d 0, 3, and 6 of storage. Sarcoplasmic proteome was analyzed, and differentially abundant proteins were identified using mass spectrometry. Color attributes and biochemical parameters were influenced by muscle source and aging ( < 0.05); LL and ST had greater ( < 0.05) surface redness than PM. Aging also influenced surface redness, with 7-d aged steaks demonstrating greatest values ( < 0.05). Proteome analysis identified 135 protein spots differentially abundant ( < 0.05) between the muscles and aging time points indicating muscle-specific changes during aging. The identified proteins included glycolytic enzymes, proteins associated with energy metabolism, antioxidant proteins, chaperones, and transport proteins. Overall, the glycolytic enzymes were more abundant ( < 0.05) in color-stable muscles and at aging times with greater color stability, indicating that these proteins could be used as potential biomarkers for beef color.