Proteome basis of muscle-specific beef color stability

摘要

The objective of this study was to differentiate the sarcoplasmic proteomes of color-stable (Longissimus lumborum; LL) and color-labile (Psoas major; PM) beef muscles and to correlate the differences in protein abundance with color stability attributes. LL and PM muscles were harvested from seven beef carcasses (USDA Select grade, 24 h post-mortem), and samples for proteome analyses were collected and frozen at -80°C. Muscles were fabricated into 2.54-cm steaks; steaks were aerobicallv packaged and assigned to refrigerated retail display for 0, 5, and 9 days. On respective storage days, a~* value (redness) and ratio of reflectance at 630 nm to 580 nm (R630/580; indicator for surface color stability) were measured. LL exhibited greater (P < 0.05) a~* value and R630/580 than PM during retail display indicating greater color stability. Two-dimensional gel electrophoresis and tandem mass spectrometry identified sixteen differentially abundant proteins, which included antioxidant and chaperone proteins and enzymes involved in energy metabolism. Proteins exhibiting positive correlation with a~* value (aldose reductase, creatine kinase, and beta-enolase) and R630/580 (peroxiredoxin-2, dihydropteridine reductase, and heat shock protein-27 kDa) were over-expressed in LL than in PM. On the other hand, mitochondrial aconitase was more abundant in PM than in LL and correlated negatively to a~* value. The greater color stability of beef LL compared to PM could be attributed to the over-expression of antioxidant (peroxiredoxin-2, dihydropteridine reductase, aldose reductase) and chaperone (heat shock protein-27 kDa) proteins. Our result suggests the necessity to develop muscle-specific antioxidant and packaging strategies to improve beef color stability.