WHC Flashcards
What is WHC?
the ability of meat to hold onto its own or added water during the application of external forces such as cutting, heating, grinding, or pressing
What are consequences of poor WHC?
- loss of weight from carcass
- affect appearance of meat
- Nutrient loss
- affect palatability
Myowater
water in lean muscle, it is closely associated with myofibrillar proteins and entrapped in tissue matrix
Name the types of Myowater
- Bound water (5%)
- Immobilized water (85%)
- Free water
Bound water
water that is bound to muscle proteins because of protein hydrophilic groups and pH
It is not released with mechanical or thermal energy input
Immobilized water
water that is constrained in the molecular matrix by steric effect
water found in the I-band
Free water
water held by capillary forces and the surrounding matrix (sarcoplasm)
easily mobilized through minor physical forces
Steric effect
a lack of space for water molecules within the protein structure because of actomyosin crossbridges
Describe mechanisms of water loss
2/3 of water loss by contraction (steric effect)
1/3 of water loss due to pH decline (net charge effect)
Net Charge Effect
when pH in meat reaches isoelectric point (5.1) so that no charge is available to hold the bound and immobilized water
What causes pH to decline during conversion of muscle to meat?
lactic acid and H+ build up
Describe WHC effect on meat color
high WHC = dark color (less water on meat surface)
low WHC = light color (more water on meat surface)
How will increasing rate of chilling affect WHC?
It improves WHC (water movements to extra-myofibrillar space are reduced)
How does PSE affect WHC?
it reduces WHC
