Tenderness Flashcards
Why is meat aged postmortem more tender than unaged meat?
Because we have proteolysis, breakage of proteins that leads to tender meat.
What is background toughness?
it is that amound of shear force/toughness we cannot remove with aging, because it is due to collagen content. The proteolytic activity does not touch the connective tissue
Describe the 3 sites where targeted cleavage of key proteins (cuts) takes place during aging
weakening of sarcolemma (and costameres), separation of myofibrils (desmin is cut) and the N2 line is degraded (fracture of myofibril near z-disc)
How does temperature affect ageing?
The higher the temperature, the quicker the tenderisation, but there are some microbial limits
What is the difference between carcass suspension by the Achilles tendon vs aitch bone?
the first is hung by the leg and the second one by the hip, the second is best except for the fillet, but it takes more space in the chiller
How can we carry out enzyme induced tenderisation through meat injection?
it is the proecss of injecting ficn, bromeln or papain to act as proteolytic enzymes, but these then need to be controlled/inactivated
Why are CaCl2 injections used in tenderisation? How do they work?
to stimulate Ca activated proteolytic enzymes
Describe what tenderbound meat is
hot boned meat, pi vac, better sensory evaluation and lower drip loss but more expensive
What are the 5 methods in which meat tenderness can be measured?
Shear force with Instron, sarcomere lenght with laser, MFI, SDS page and the 30 kdal fragment, sensory
What is the difference between sensory analysis with consumers vs trained panels?
different questions can be asked, different numbers are needed
Explain how the 30kdal fragment is used to measure meat tenderness
it is a by-product of troponin T degradation, so with aging time, troponin T becomes lighter in the SDS page and the 30kdal fragment becomes more evident.
Provide the names of some of the proteolytic enzymes implicated in aging
Ca2+- activated neutral proteinase, Lysosomal acidic proteinase, MPC - multicatalytic proteinase complex, Caspases
