Location: Meat Safety & Quality ResearchTitle: Investigation of the sarcoplasmic proteome contribution to the development of pork loin tenderness
|SCHULTE, MATTHEW - Iowa State University|
|JOHNSON, LOGAN - Iowa State University|
|ZUBER, ELIZABETH - Iowa State University|
|STEADHAM, EDWARD - Iowa State University|
|King, David - Andy|
|HUFF-LONERGAN, ELISABETH - Iowa State University|
|LONERGAN, STEVEN - Iowa State University|
Submitted to: Meat and Muscle Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2020
Publication Date: 4/1/2020
Citation: Schulte, M.D., Johnson, L.G., Zuber, E.A., Steadham, E.M., King, D.A., Huff-Lonergan, E., Lonergan, S.M. 2020. Investigation of the sarcoplasmic proteome contribution to the development of pork loin tenderness. Meat and Muscle Biology. 4(1):8, 1-14. https://doi.org/10.22175/mmb.9566.
Interpretive Summary: Tenderness continues to be a primary driver of consumer acceptance of pork products. Current knowledge of the biological factors regulating pork tenderness leaves a significant portion of variation in tenderness unexplained. An experiment was run to determine differences in protein profiles of pork loin muscles that differed in tenderness. Tougher pork loins had a greater abundance of metabolic and regulatory proteins. In contrast, more tender pork loins had greater abundance of proteins responsible for cellular stress response. These results provide insight to new avenues to understanding biological regulation of pork tenderness.
Technical Abstract: 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.