Investigation of the Sarcoplasmic Proteome Contribution to the Development of Pork Loin Tenderness
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The study objectives were to determine the extent to which the sarcoplasmic proteome explains variations in aged pork loin star probe value. Pork loins (n=12) were categorized by differences in star probe at 21 d post mortem from a larger set of loins. Loins were categorized into low star probe (LSP) group (n=6; star probe<5.80 kg) and high star probe (HSP) group (n=6; star probe>7.00 kg) based on 21-d star probe value with inclusion criteria of marbling score (1.0–3.0) and 24-h pH (5.69–5.98). Quality traits were measured at 1-, 8-, 14-, and 21-d aging. Desmin and troponin-T degradation, peroxiredoxin-2 abundance, calpain-1 autolysis, and sarcomere length were determined. Two-dimensional difference gel electrophoresis and mass spectrometry were used to identify proteins that differed in abundance due to category. Star probe values were lower (P<0.01) in LSP at each day of aging compared with HSP. Greater pH values were observed (P<0.05)in LSP compared with HSP at each day of aging. Marbling score was greater (P<0.05) in LSP compared with HSP at each day of aging. Greater (P<0.05) desmin and troponin-T degradation was detected in LSP chops at 14- and 21-d aging and 8-, 14-, and 21-d aging, respectively. Greater (P<0.05) sarcomere length was determined in LSP compared with HSP at 1-,8-, and 21-d aging. Sarcoplasmic proteins from HSP chops had greater abundance (P<0.10) of metabolic and regulatory proteins, whereas the LSP chops had greater abundance (P<0.10) of stress response proteins. Star probe values were affected by pH, marbling score, protein degradation, sarcomere length, and sarcoplasmic proteome.
This article is published as Schulte, M. D. & Johnson, L. G. & Zuber, E. A. & Steadham, E. M. & King, D. A. & Huff-Lonergan, E. J. & Lonergan, S. M., (2020) “Investigation of the Sarcoplasmic Proteome Contribution to the Development of Pork Loin Tenderness”, Meat and Muscle Biology 4(1). doi: https://doi.org/10.22175/mmb.9566. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.