Mechanism of rigor mortis acceleration and the associated tenderization in broiler muscle /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Three experiments were conducted to characterize rigor acceleration, tenderness, and the associated biochemical and proteolytic mechanisms of tenderization in early-harvested broiler meat subjected to different rigor-accelerating treatments. In experiment 1, combinations of high (HV) or low voltage (LV) electrical stimulation (ES), high temperature conditioning (HTC) and muscle tensioning (MT) were investigated as treatments in the prevention of toughening of early-harvested broiler pectoralis. Broilers were assigned to each of 6 treatments including HV/HTC, HV/HTC/MT, HV/MT, LV/HTC, LV/HTC/MT, and a control which simulated commercial processing. Shear values showed that LV/HTC/MT and HV/MT tenderized meat most effectively. These two systems were selected for biochemical and proteolytic characterization. In experiment 2, broiler carcasses were subjected to each of the selected treatments and untreated control. A homogeneous red muscle, the anterior latissimus dorsi (ALD), and a homogeneous white muscle, pectoralis, represented red and white fibers respectively. The treatments affected pH similarly in both fiber types with control having the highest 1-h pH followed by HV/MT and LV/HTC/MT respectively. The R-values were different (P[less than or equal to].05) in the pectoralis with LV/HTC/MT having the highest value and control the lowest. There was no difference in R-values of the ALD (P >.05). The HV/MT fragmented myofibrils most effectively in the pectoralis while LV/HTC/MT was most effective in the ALD. The sarcomere lengths in both fiber types were similarly affected with LV/HTC/MT having the longest sarcomeres followed by control and HV/MT respectively. In experiment 3, the proteolytic tenderizing mechanism was determined after aging of rigor-accelerated, early-harvested pectoralis. Rigor acceleration resulted in lower pH and fragmentation at 1 h post-mortem compared to control. Calpain II activity was greater in muscles from treated than control carcasses while calpain I activity was lowest in all 24-h post-mortem samples. Sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) indicated a 30 kDa polypeptide was absent at death but appeared in control and treated carcasses. These results suggested that rigor-accelerating treatments resulted in more tender early-harvested meat by a mechanism involving myofibrillar proteolysis. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Food Science and Technology." |
| Physical Description: | xi, 109 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |