1 / 24

Farm Gate to Dinner Plate

Farm Gate to Dinner Plate. Meats unit. Muscle. Muscle must convert from its physiological function of movement to its use as food Living tissue has an effect on meat quality. Muscle. Muscle function efficiently within a narrow range of physiological conditions pH is neutral =7 Temperature

essien
Download Presentation

Farm Gate to Dinner Plate

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Farm Gate to Dinner Plate Meats unit

  2. Muscle • Muscle must convert from its physiological function of movement to its use as food • Living tissue has an effect on meat quality

  3. Muscle • Muscle function efficiently within a narrow range of physiological conditions • pH is neutral =7 • Temperature • Oxygen

  4. Homeostasis • Maintenance of a narrow range of physiological conditions where tissue functions efficiently. • Regulation of homeostasis gives muscle the ability to function under stress

  5. Homeostasis • Regulated by 2 body systems • Nervous system • Endocrine system • Loss of homeostasis is necessary to convert muscle into meat

  6. Immobilization • To render unconscious • Effects of Homeostasis • Elevated blood pressure • Nerve stimulation

  7. Exsanguination • Bleeding out • Effects on Homeostasis • Severe compromise of homeostasis • Severe drop in blood pressure • Heart pumps faster • Peripheral blood vessels constrict and force blood to the vital organs • Only 50% of blood is removed from carcass

  8. Exsanguination • Loss of circulatory system • Nutrients cannot be transported to the muscle • Waste products cannot be transported away.

  9. Effect on Metabolism • Stored oxygen is quickly depleted • Aerobic metabolism cannot occur • Respiratory system is eliminated • Muscle switches to anaerobic metabolism

  10. Anaerobic Metabolism • Uses glycogen as energy source • Glycogen is the storage form of glucose • Glycogen builds up in the muscle over time under normal conditions

  11. Anaerobic Metabolism • Heat is produced • Body temperature actually spikes during harvest and then begins to fall • Build up of Lactic acid-product of anaerobic metabolism

  12. Lactic Acid • Drops the pH • Living Muscle – pH of 7.4 • Meat – pH of 5.6 • Quality problems with pH • Dark cutter – Beef • PSE (Pale Soft Exudative) - Swine

  13. Rigor Mortis • Stiffening of the muscle after death • Permanent cross bridge formation between actin and myosin • Four Phases

  14. Rigor Mortis • Delay- energy available so muscle can stretch when load is applied • Onset- begin to lose its ability to stretch, some permanent cross bridges are formed- 2hours postmortem

  15. Rigor Mortis • Completion- No ability to stretch, all permanent cross bridges • Resolution- Break down of proteins by enzymes • Aging • Not breaking the cross bridges

  16. Temperature and pH • Relationship is critical for development of good quality meat • Biggest affect on this is stress

  17. Stress • Two types • Acute Stress-one time or short term stress • Chronic Stress-long term continuous stress

  18. PSE • Pale Soft Exudative • Caused by acute stress prior to harvest

  19. PSE • Stress prior to slaughter results in: • Increased muscle temperature • Rapid anaerobic metabolism • Build up of lactic acid

  20. PSE • After harvest • Temperature increase and pH drops rapidly. • Rapid decline of pH at high temperatures cause proteins to denature or break down.

  21. PSE • Pale- the protein responsible for color leaks out when the proteins denature • Soft- denatured proteins are mushy • Exudative- denatured proteins cannot hold water

  22. Dark Cutter • Results from chronic stress • Chronic stress depletes muscle glycogen • If there is no glycogen built up in the cells before harvest there is no fuel for anaerobic metabolism

  23. Dark Cutter • If anaerobic metabolism is limited there is little to no lactic acid produced • If lactic acid is limited the pH of the muscle does not decline

  24. Dark Cutter • Makes meat dark, firm, and dry • Higher pH makes for a more favorable environment for bacterial growth.

More Related