Harvesting Flashcards
What does muscle pH gradually decline to post-mortem?
5.5 from 7.0.
What are the 5 reasons that muscle pH experiences the fluctuation it does post-mortem?
- Glycogen depletion.
- Oxygen depletion leading to anaerobic respiration as a result of exsanguination.
- Lactic acid build-up.
- Inactivation of some glycolysis enzymes.
What other energy source is depleted post-mortem?
Creatine phosphate.
What is rigor mortis a result of?
Myosin heads tightly bond actin and muscle filaments will no longer slide due to no calcium being present.
What are the 2 ways that rigor mortis is overcome naturally?
- Z-Line breaking.
- Partial degradation of troponin.
What is the primary candidate for protein degradation?
Calpains or calcium-activated proteins.
What substance inhibits calpains?
Calpastatin.
How long are hogs held off of feed before slaughter?
14-16 hours.
Why are hogs held off of feed before slaughter?
- To assure bleeding completeness.
- Ease of evisceration.
- Reduction of carbohydrates available to become lactic acid.
What characteristics does meat with less lactic acid have?
- Higher ultimate pH.
- More desirable color.
- Increased water-holding capacity.
How is dressing percentage calculated?
(Hot carcass weight/live carcass weight)*100.
What is the average dressing percentage of a hog?
70%.
Approximately how much weight does a hog carcass lose during chilling due to moisture evaporation?
2%.
Hogs with what carcass traits tend to dress higher?
- Fatter.
- Heavier muscled.
- Heavier hogs.
What carcass trait in hogs results in dressing lower?
Excessive fill.
What are the 3 acceptable stunning methods for use in hogs?
- Electric.
- Mechanical.
- Chemical (CO2).
What must the electrical stunning method induce in hogs?
Cardiac arrest.
*Reduced blood splashes in the muscles.
What are the 3 methods of mechanical stunning used in hogs?
- Mushroom compression bolt.
- Penetrating compression bolt.
- .22 caliber rifle.
What does the use of CO2 reduce the incidence of?
- Blood splashing.
- Shoulder and backbone fractures.
- PSE.
What is exsanguination?
The severing of the carotid arteries and jugular veins in a way that leaves a hole no wider than the knife blade.
When is exsanguination done?
Immediately after stunning.
Why is the blood from exsanguination caught?
If it reaches the sewers, it will create a biological oxygen debt (BOD) that will retard sewage drainage.
Why is scalding done?
To loosen the hair on the hog carcass for easier removal.
What temperature should the water be during scalding?
143 F.
When is hard-hair season? Easy-hair season?
- September-November.
- February-March.
What can overscalding result in?
The cooking of the skin, risking contamination.
What is the purpose of the polisher?
The removal of scurf (flakey skin tissue) and leftover hair.
What is removed following the polisher?
The toenails and the hair+skin between the toes.
Why are the two tendons in the hindfoot exposed during harvesting?
To allow the hog to hang.
What must be done to the head of a hog for it to be utilized for human consumption?
Eyebrows and inner ear hairs must be removed.
What is singeing?
Passing the hog through flames to remove small, tough hairs that were not removed during scalding.
Where is the head removed at on hog?
At the atlas joint, preserving as much of the jowl as possible.
What are the steps of evisceration in hogs?
- Freeing the pizzle (penis) w/o cutting it.
- Split the aitch (sacrum) bone at its midpoint.
- Bunging.
- Split the sternum.
- Open the ventral portion of the hog.
- The bung is pulled firmly, ureters are cut, diaphragm is cut, membranes and connective tissue connected to backbone is cut to allow internal organs to fall out.
- Pluck (thoracic contents) are removed.
- Inspection of everything removed.
What is bunging?
The loosening of the anus and reproductive tract that is then tied off for safety.
What happens following evisceration?
- The carcass is split in half.
- Leaf fat (fat around kidneys) and kidney are removed.
- Facing of the hams ().
What are 3 solutions a hog carcass may be washed with?
- Mild salt (0.1M KCl).
- 2% lactic acid.
- 3% acetic acid.
What temperature is a hog carcass kept at and for how long?
32-34 F (5-15 mph air velocity to feel like 23 F) for 24 hours.
What is the maximum line speed in a hog processing plant?
1106 hogs/hour.
*Some approved to go faster.
How long are cattle held off of feed before slaughter?
24 hours.
Why are cattle held off feed before slaughter?
- Bled out more thoroughly.
- Easier to dress.
- Brighter appearance to carcass.
What does rough handling or excitement before harvest in beef cattle result in?
Fiery carcass (pink tinges in the fat).
What is the average dressing percentage of cattle?
60%.
What are the acceptable stunning methods used in cattle?
- Compression gun (mushroom and penetrating bolt).
- Rifle.
What is the procedure for kosher slaughter?
Live animal is suspended (unstunned) and a shohet makes an incision across the throat with a razor sharp 14 inch blade.
What part of the cattle do Jewish people eat?
Forequarter.
What is the procedure for halal slaughter?
A Muslim must perform the slaughter in the appropriate ritual manner, and the animal must be alive and healthy before slaughter, and a sharp knife severs the carotid artery, jugular vein, and windpipe with a single swipe.
*Stunning must be reversible.
What is exsanguination?
The severing of the carotid arteries and jugular vein to allow the animal to bleed out.
Why are beef carcasses electrically stimulated?
- Accelerate anaerobic glycolysis.
- Increase rate of muscle pH decline.
- Reduce time to rigor mortis.
- Improves bleeding.
- Easier hide pull.
- Improve carcass traits.
- Reduced heat ring.
What 5 carcass traits are improved by electrical stimulation in cattle?
- Quality grade.
- Firmness.
- Tenderness.
- Texture.
- Lean color.
What is heat ring in cattle?
Outer portion of the ribeye appears darker and coarser, often sinking or dropping down.
What is rodding the weasand?
Separating the trachea from the esophagus by inserting a rod into the esophagus.
*A knot is tied in the esophagus afterwards to prevent spillage of rumen contents.
What parts are removed after rodding the weasand?
The head and feet.
What steps are taken once the hide has been removed in cattle?
- Splitting of the brisket and sternum.
- Splitting the aitch bone.
- Free the pizzle.
- Bung.
- Remove the tail at the 2nd vertebrae from the base.
What remains in the carcass during evisceration in beef cattle?
- The diaphragm/skirt/hanging tenderloin muscle.
- Kidney and kidney fat.
What follows evisceration in beef cattle?
- Halving.
- Washing.
- Final inspection.
- Chilling for 24 hours.
At what temperature is beef cattle chilled?
32 F but the room is kept at 27 F with a 5-15 mph air velocity (12 F wind chill) due to the introduction of hot carcasses.
What is cold shortening?
An intense shortening of the muscle fibers that results in tougher meat.
What is the maximum line speed for cattle harvest?
390 head/hour.
How many hours are lambs fasted before harvest?
24 hours.
*Do not withhold water
What 3 reasons are lambs fasted before harvest?
- Easier pelt remover.
- Easier evisceration.
- Brighter appearance to the meat.
What is the average dressing percentage of lambs? In heavy-muscled and fatter lambs?
- 50%.
- 54-55%.
What are the acceptable stunning methods used in lambs?
- Captive bolt.
- Electric Stunning.
What part of the lamb is skinned first?
The forelegs and rear legs.
How are the forefeet removed from lambs?
They are snapped off, to make a break or spool joint.
How is hide separated from the belly and sides of the lamb?
By fisting, in order to maintain the fell.
What is fell in lamb?
The colorless, thin connective tissue membrane
Where is the pelt pulled off of once it is loosed in lamb?
The back.
What happens after pelt removal in lamb?
- Separate the esophagus and trachea, tie off esophagus.
- Free the pizzle.
- Bung.
- Open the abdominal cavity.
- Remove all viscera but kidneys.
- Wash.
- Final inspection.
- Chill overnight.
How many hours before harvest are poultry held off of feed?
8-10 hours.
Why are poultry held off feed prior to harvest?
- Bleed better.
- Easier to eviscerate.
- Longer decreases dressing yield.
How is poultry processing different from the other types of meat processing?
It is highly mechanized.
How are poultry immobilized during processing?
Shackles.
What are the acceptable methods for stunning poultry?
- CO2 (before immobilization).
- Electrical (after immobilization).
How do you debrain chicken?
Forcing a blade into the cleft of the roof of the mouth through the medulla oblongata.
What does debraining the chicken lead to?
Relaxation of the feather muscles to allow easier plucking.
*Only lasts 2-3 minutes.
What are the 3 types of scalding used in poultry processing?
- Hard/hot scalding.
- Semi-scalding/slack scalding.
- Wax picking.
What is hard/hot scalding?
Dipping the poultry into a bath that is above 155 F to soften the feathers and make them easier to remove.
*Not used commercially.
What is semi-scalding/slack scalding?
Dipping the poultry into a bath that is 125-132 F, depending on the bird, to soften the feathers and make them easier to remove. This is followed by the automatic picking machine.
What is wax picking?
Dipping the birds in hot wax following semi-scalding and picking. The wax is pulled off the birds once it has cooled to remove any feathers, pinfeathers, scales, or hair.
*Used in ducks and geese.
What conditions are poultry stored in?
32-36 F ice slush baths.
What do the ice slush baths contain?
Phosphates, which the carcasses absorb some of.
What is the line speed for poultry processing?
140 birds/min. or 8400/hour.
*Some plants can do 175 birds/min. or 10500/hour.
