Class
Article
College
College of Agriculture and Applied Sciences
Faculty Mentor
Sulaiman K. Matarneh
Presentation Type
Poster Presentation
Abstract
In fresh meat products, the most important attribute dictating consumer satisfaction is tenderness. Accordingly, researchers have rigorously studied the biochemical mechanisms involved in meat tenderization during aging, and found that proteolytic degradation of structural muscle proteins is one of the major mechanisms. Postmortem proteolysis is driven by endogenous proteases present in the muscle, and calpain-1 has been identified as the main protease involved in the tenderization process. Calpain-1 is a calcium-dependent protease that rely on calcium to become proteolytically active. Recently, mitochondria have garnered interest due to their ability to sequester and decrease cytosolic calcium concentration. However, it remains unclear whether mitochondrial content and intactness can influence the rate of postmortem proteolysis by calpain-1. Therefore, the objective of this research was to examine the role of mitochondria modulating calcium concentration and proteolysis in bovine muscle. Because it is difficult to manipulate mitochondrial content in vivo, an in vitro model that recapitulates postmortem conditions was utilized in this study. For this model, powdered muscle samples collected early postmortem were homogenized in a reaction buffer containing all the constituents required for postmortem metabolism. Mitochondria were then incorporated into the buffer at 0, 0.5, and 2 mg/ml. Aliquots were taken at different time points to evaluate proteolysis and free calcium concentration. Our obtained results indicate that added mitochondria were able to decrease free calcium concentration (P < 0.05), proteolysis (P < 0.05), and calpain activation (P < 0.05) in the in vitro model. The next step of this research is to test the relationship between mitochondrial intactness and their calcium buffering capacity. These data will allow to better understand the role mitochondria play in postmortem proteolysis and tenderization. Presentation Time: Thursday, 9-10 a.m.
Location
Logan, UT
Start Date
4-11-2021 12:00 AM
Included in
Mitochondria Delay Proteolysis in an In Vitro Model Simulating Postmortem Conditions
Logan, UT
In fresh meat products, the most important attribute dictating consumer satisfaction is tenderness. Accordingly, researchers have rigorously studied the biochemical mechanisms involved in meat tenderization during aging, and found that proteolytic degradation of structural muscle proteins is one of the major mechanisms. Postmortem proteolysis is driven by endogenous proteases present in the muscle, and calpain-1 has been identified as the main protease involved in the tenderization process. Calpain-1 is a calcium-dependent protease that rely on calcium to become proteolytically active. Recently, mitochondria have garnered interest due to their ability to sequester and decrease cytosolic calcium concentration. However, it remains unclear whether mitochondrial content and intactness can influence the rate of postmortem proteolysis by calpain-1. Therefore, the objective of this research was to examine the role of mitochondria modulating calcium concentration and proteolysis in bovine muscle. Because it is difficult to manipulate mitochondrial content in vivo, an in vitro model that recapitulates postmortem conditions was utilized in this study. For this model, powdered muscle samples collected early postmortem were homogenized in a reaction buffer containing all the constituents required for postmortem metabolism. Mitochondria were then incorporated into the buffer at 0, 0.5, and 2 mg/ml. Aliquots were taken at different time points to evaluate proteolysis and free calcium concentration. Our obtained results indicate that added mitochondria were able to decrease free calcium concentration (P < 0.05), proteolysis (P < 0.05), and calpain activation (P < 0.05) in the in vitro model. The next step of this research is to test the relationship between mitochondrial intactness and their calcium buffering capacity. These data will allow to better understand the role mitochondria play in postmortem proteolysis and tenderization. Presentation Time: Thursday, 9-10 a.m.