Exsanguination
• The drainage of blood is called Exsanguination
• Slit throat of animals causes quick Exsanguination
• Cut carotid artery ensures that brain gets no blood
• Cut jugular artery quickly drains the brain
• Brain quickly looses functionality due to ischemia
• Complete drainage occurs in about two minutes
• By the end of the process 30-50% blood remains in the body
• Deteriorates faster than meat• Congests in the vesicles
• Blood starts deteriorating inside the body
• can provide medium for a local infection to spread generally
• Can have pathogens, microbes and parasites
• Causes red carcass decreasing shelf life and palatability
• Contains hormones
• Cytokines that stimulate functioning of cells
• Stress hormones that are released during restraining and sticking
• Cortisol and histamine that cause plasma to leak into tissue
causing edema due to capillary dilation.
Blood
BloodIfRetained
• Bacterial growth occurs quickly after slaughter
• Meat has blood color and bad metallic smell
• Meat color changes over time From red to blue and then black
• Gory and unsightly carcass
• Any microbe present anywhere in the body generalizes
• Blood contains buffers
• The pH of meat cannot drop, required acidity cannot
be achieved hence reducing the meat shelf life
• microbes growth is retarded at low pH which cannot happen if blood
is retained
• Blood also harbors antigens and some humans can potentially be allergic
• Hemoglobin degradation increase oxidation causing excessive and quick
rancidity
Stunning
• Animals can be stunned prior to bleeding but evidence suggests
That it does not affect the bleeding in any way
• The bleeding rate and carcass clearance remains unaffected
• Stunning is done by traumatizing the brain
• concussion
• Free bullet
• Sinusoidal electric shock
• It is meant to make the slaughter more humane but experiments
show that the execution of this process is indifferent for the animal
Bleeding:The Right Way
Stick sharpest of knives only:
• About 15cm plain knife
• Single stroke
• Incise the arteries
• No rough edges on the arteries
• Smooth free ends of vesicles
• No premature coagulation
• Blood flows steadily
• Thorax should be avoided from incising or chest will fill with blood
• The most hygienic system of bleeding and dressing:
• Shackle the animal immediately after stunning and
then hoist it on to a moving rail
• The animal is stuck while being hoisted to minimize
the delay after stunning Bleeding continues until the
blood flow is negligible
• carcass dressing should begin without further delay
• Gullet of the knife collects Blood for human use to
avoid contamination from the wound
• The knife may be connected to a hose to reduce the
risk of contamination. The hose may even be
connected to a pump to speed the blood flow
• Between 40 and 60 percent of the total blood
volume will be removed though this will be reduced if
sticking is delayed.
• To prevent coagulation, citric acid solution made up
with one part citric acid to two parts water is added
at a rate up to 0.2 percent of the blood volume.
• If esophagus is pierced semi-digested food may be
regurgitated contaminating the blood and neck
wound.
Bleeding on a rail
• Horizontal bleeding is claimed to give faster
bleeding rates and a greater recovery of blood
• This may be due to certain organs and blood vessels
being put under pressure when animals are hoisted
thus trapping blood and restricting the flow
• Bleeding on the floor is very unhygienic
• The operation should take place on a specially
designed, easily cleaned stainless-steel table which
should be cleaned frequently
• If blood is to be saved it must not come in contact
with the table before reaching the collecting vessel.
Horizontal bleeding
Ritualistic bleeding
Dabeehah and Sechitha• Closely related to each other
• Require no stunning but need great skill
• Produce Hilal And Kosher Meat
• Only Muslim or Jew allowed to carry out procedure
• Centered around welfare and minimal
pain while achieving maximum purity
by removing maximum blood
• Properly done; the meat from both processes
is perfectly healthy for human consumption
Delayed Bleeding
• Dressing percentage, chilled carcass weight and the pH are not
affected by delayed bleeding
• The volume of blood drained decreases as the period between
stunning and bleeding increases
• The drip loss and cooking loss increases as the time between stunning
and bleeding increase while the Water Holding Capacity (WHC)
decreases
• The effect of delayed bleeding on shear force, WHC, drip loss and
cooking loss became more pronounced with ageing
• Apart from the color and juiciness rating that significantly decreases,
the other eating qualities are not affected by delayed bleeding.
Improper Bleeding
• The neurological, cardiological and muscular effects of stunning can
impede Blood loss though there is no significant difference
• Exudation occurs more in case of meat that is improperly bled
• Exudation occurs more in case of meat of animal that was stunned
before sticking
• Even more so in case of electrically stunned animals
• Cooking loss of >22% is seen in improperly bled animals while kosher and
halal meat show <18% cooking loss
• About 20% trachea fills with blood when animals are stunned while
<10% in case of kosher and Hilal
• Alveolar capillary network ruptures when lungs cannot drain
immediately
• Carcasses of male animals decompose faster if improperly bled than
those of female carcasses; also in the case of stunned vs. Hilal and
Kosher
• Male carcasses are generally redder than female ones
• Even less amounts of retained blood imparts more color as the
blood is denser in all aspects
• Improperly bled carcasses cause slower pH drop as the blood acts as
buffer though glycolysis occurs at similar rate
Carcass QualityResidual Blood
&
The results of excessive bleeding caused by different stunning techniques and
by imperfect slaughter increase the hemoglobin concentration in the muscle
and decrease the organoleptic quality. The increase in red and yellow color
causes the pink coloration which is due to the imperfectly bleeding and which
may lead to a downgrading of the carcasses. Samples from imperfectly bled
carcasses also show a high value of Lightness(54.09) which produce a pale
color. Residual blood is among the key factors affecting the quality of the meat
color. Bruises, hemorrhages, and poor exsanguination efficiency can
negatively affect color of the meat and skin; these are major quality defects
and are associated with undesirable discoloration and reduced shelf life
Colorimetric Analysis
Carcass QualityResidual Blood
&
variability of pH standards for meat chickens are be-tween 5.7 to 6.20. Normal
values of ultimate pH ranged from 5.7 as minimum normal value and 6.25 as
maximum normal value, outside this range, and lower values to 5.7 meats
have defects and are called
• PSE (pale, soft, exudative)
For higher values to 6.25 meats have defects and are called
• DFD (dark, firm and dry) .
At 7°C storage temperature, the average pH of perfectly bled meat is (6.07)
which was significantly lower than the average pH of imperfectly bled one
(6.27).
A rise in the storage temperature increases the pH but the pH of the perfectly
bled meat is still minimal. There is a strong relationship between carcass
residual blood and the growth of the degree of pH, but also indicates the
season effect. The lowest level of pH is recorded during the winter. After this
period the values increase to reach the highest rate in the summer, especially
at 7°C storage.
pH
Dabeehah and Sechitha seem
to be the best methods of
slaughter. Good and skillful
practices in hygienic conditions
without stunning and with
proper Exsanguination ensure
no residual blood in meat and
optimal meat properties for
human consumption.
Evidently
Improperly BledpH of 6.9-7.2
Color Dark red
Taste Metallic or other (fungi, bacterial
or drugs)
Pungent, sour smell depends on type of
growth.
Degraded even in proper storage.
Shelf life decreased Properly BledpH of 6.0-6.9
Color pale red
Taste Meaty
No smell
No growths
Able to survive a few weeks in proper
storage.
Shelf life increased
Overview