Lecture 6 & 7
Blood Utilization
Utilization of Animal By-Products
Dr. Fa-Jui Tan
2009 Class handout
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Blood in animals
• 5-7% of the body wt of mammals
– 2.4-8% of the animal’s live wt
– dried blood makes up to 0.7% of live wt.)
• Remove of blood
– Approximately 50% of blood is collected during bleeding
in the slaughter operation.
• 50% retained in the capillary sys throughout the body
• May cause environmental pollution hazard
– Effective remove of blood during slaughter
• Moslem and Jewish
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Characteristics of blood
• Usually sterile in a healthy animal
– Human uses: must be inspected vs. non-human uses
• Composition
– Blood “liquid meat”
• Protein: 18~19%
– used as protein supplement
– A potential source of large quantities of dietary protein
– Well balanced in amino acid composition
• Moisture: 78~79%
• Ash: 0.8~1.2%
• pH 7.4
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Blood composition
• Plasma
– Fluid part of blood
– Various cellular components suspended
• Blood cells: 40% of total blood volume
– Red cell (erythrocyte):
• carrying oxygen
• Hemoglobin pigment
– White cell (leukocytes)
– Platelets: blood clotting
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Blood Plasma
• Blood = plasma + blood cell
• Blood plasma
– contains globulins, albumins, and fibrinogen
– Color
• Beef plasma: yellow or orange
• pig plasma: gray-white to pink
• The darker color of the plasma
– is due to hemoglobin
• either because of incomplete separation
• or because of hemolysis of the erythrocytes
• Haemolysis (lysis)
– can be prevented by careful mechanical handling of the blood in pipes, joints,
and valves
– and by minimizing dilution of blood with water from the cleaning operation.
– Additional water in the blood will decrease the osmotic pressure in the plasma,
2009 Class handout which may result in the bursting of the erythrocytes.
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General Properties of Blood Fractions
• Blood
– is composed of cellular and liquid components.
– Blood = blood plasma + blood cells
• Blood plasma
– If anticoagulants are added and erythrocytes are removed by
centrifugation from liquid blood, then the remaining liquid is called
“plasma” and contains fibrinogen (protein).
• Blood serum
– is obtained when blood coagulates, because the serum does not contain
fibrinogen.
– Serum = blood plasma – fibrin
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3
Composition of blood
Blood
Blood
plasma
RBC
Concentrate
Dried
Plasma
Dried
Globin
Dry solid (%)
18-20
8-9
28-37
96-97.5
96.5
Protein (%)
13-15
6-8
28-38
70-96
91-95.4
Albumin (% of
protein)
50
Globulins (% of
protein)
23-27
Fibrinogen (% of
protein)
17-23
Fat (%)
<1
0.1-1
1
0-1.5
0
CHO (%)
<1
<1
<1
-
-
Water (%)
80-82
90-91
61-63
2.5-7.0
3.5
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Whole blood (100%) + anticoagulant
↓
centrifuging
↓
Plasma (65%) + red cells (35%)
↓
↓
Evaporation
concentration
↓
↓
spray drying
spray drying
↓
↓
plasma powder (6%) red cell powder (12.5%)
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4
Structure of myoglobin & hemoglobin
• Complex protein
– typical protein attached to a non-protein
type structure
• Globin
– Protein portion
– Most (approx. 95%) of the MW and size
• Heme
– Fe atom and a large ring (porphyrin)
– Responsible for meat color and post of
the O2 carrying properties
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Hemoglobin
Myoglobin
Molecular weight
4*(16,000-17,000) 16,000-17,000
Heme groups
Iron per molecule
Oxygen binding
equivalent/weight
4
4
Same
1
1
Same
Oxygen affinity due to
binding of heme
Lower
Higher
Amino acid units in
protein
574
Approx. 150
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Blood utilization
•
Edible blood (food)
•
Feed (blood meal)
•
Fertilizer
•
Laboratory uses
– Emulsifier, stabilizer, clarifier, colour, additive, nutritional component.
– Lysine supplement, vitamin stabilizer, milk substitute, nutritional component
– Seed coating , soil pH stabilizer, mineral components.
– Tissue –culture media, tannin analysis , active carbon, haemin, blood agar,
peptone, glycerophosphstes, albumins, globulins, sphingomyelins, catalase.
•
Medicine
– Agglutination tests, immunoglobulins, fractionation techeniques, blood clotting
factors, sutures, fibrinogen, fibrinolysin, fibrin products, serotonin, kalikrenis,
plasminogen, plasma extenders.
•
•
Industrial uses
Transfusion
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Blood utilization: Edible blood (Food)
• Uses
–
–
–
–
–
Used in blood sausage, soup,… as protein supplement
Emulsifier
color additives
nutritional component
Blood albumin: as a substitute for egg albumin in food
• If adding too much
– Change end-product color (darker) and often unpalatable
– Use of only plasma
• Frozen plasma mixed with emulsion meat products
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Blood utilization: Feed
• blood meal for livestock feed
– Nutrimental component, protein supplement
– As a stabilizer for fat in bone meal
– Good source of most of the trace minerals
• Production of blood meal
– Cooking blood → expressing the excess water →drying blood →
granular product
• Characteristics of blood meal
– Rich source of lysine
• 10-12% with spray drying
– Deficiency in tryptophan, isoleucine
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Blood utilization: Fertilizer
• Purposes
– Mineral components: nitrogen
– Useful in regulation soil pH
– Improve the soil structure
• Disadvantage
– Attracting rats and vermin when spreading on the
soil
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Blood utilization: Laboratory & medicine
• Uses
– Nutrients for tissue culture media and as a
necessary in some agar for bacteriological use
– Many isolated blood components
• Used in chemical analysis or as nutritive supplements
• Blood plasma: as a diluent for boar and bull semen
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Blood utilization: Industry
• Uses
– Adhesive, resin extender, finishes for leather and
textiles, insecticide spray adjuvants, egg albumin
substitute, foam fire extinguisher, porous concrete,
ceramic and plastic manufacture, plastic and
cosmetic base formulations.
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Edible blood collection: Procedures
• Sticking knife → Blood collection →
inspection → + anticoagulant → cooler &
insulated storage tank as whole blood (or)
→centrifuging → separating into plasma (5070%) + erythrocytes (30-48%) fractions →
cooling from 35C to 2C → pumping into
storage tanks (or) freezing (or) drying →
shipment
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Edible blood collection: Quantity
•
Bleeding time
– Normal bleeding time used in industry
• cattle: 6 min, sheep: 4-5 min, calves: 3-4 min, pigs: 6 min
•
Quantity of blood collected
– Approximately 50% of the blood is collected during bleeding in the slaughter
operation. The remaining blood (approximately 50%) is retained in the
capillary system throughout the body.
•
Blood collection amount
– Hogs: approximately 2.5 L
– Sheep: 1.5 L
– young chickens: approximately 10% of the body weight.
•
A closed bleeding system
– To incorporate reduced pressure to speed up the collection process and to
accomplish a more complete removal of blood from the animal.
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Edible blood collection: Quality
• Sources
– Animal has been inspected and passed for use in meat food (only from
healthy animals)
• Blood taken from healthy animals is essentially sterile.
• After collection, blood needs to pass inspection. Then the blood can be
used for human utilization.
– Environment
• Blood which comes is contact with the surface of an animal or is otherwise
contaminated should not be collected for food purpose.
– Facility and equipment
• a specially designed hollow knife to which a hose is attached, which allows
the blood to flow into a container.
– knife is sterilized between each sticking operation.
• A collection tank has two arrangements for the removal of blood: one for
approved blood and the other for condemned blood.
– The number of cattle from which blood is collected into one tank is
determined by the likelihood of condemnation of a carcass, which in turn
would contaminate the whole tank of blood, and by the time lapse between
2009 Class handout slaughter and meat inspection carcass approval.
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Blood collection - anticoagulation
•
Anticoagulants
– usually added in the hollow knife
– After bleeding, blood clots in 3-10 min. This clotting is caused by thrombin,
which converts soluble fibrinogen in the blood into insoluble fibrin.
– Fibrinogen + thrombin →Fibrin
•
Common use anticoagulant
– 0.2% trisodium citrate (sodium citrate) or citric acid in the amount of
• Sodium citrate (3 g/l, 3000 ppm), and it converts the calcium into a nonionized form,
preventing coagulation.
– A mixture of phosphates has also been used as an anticoagulant
• mixture of 22% of Na2HPO4, 22% Na4P2O7, 16% Na2H2P2O7 and 40% NaCl.
• sodium hexameta phosphate or sodium acid pyrophosphate (135ml of 8% solution
per liter blood collected )
– Also, heparin or oxalates have sometimes been used.
– 1.2~1.5% Salt (Taiwan)
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Blood collection - anticoagulation
•
Heparin
– natural blood component that helps prevent coagulation in the live animal
during blood circulation
– Commercially, it is available in the sodium, lithium, or calcium salt, and it
inhibits the formation of thrombin from prothrombin.
– often used at the rate of 200 mg/l of blood when the blood is to be used in the
food or pharmacological areas.
•
Ethylene diamine tetraacetic acid disodium salt (EDTA)
– 2 g/l (2,000 ppm)
– acts by chelating the calcium ion needed for coagulation
•
Oxalate
– Precipitate calcium needed for coagulation
– Poisonous, not used for blood which used for food or pharmaceutical uses
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Blood collection - anticoagulation
• Rapid chilling of blood to 1-2°C
– will prevent coagulation without an anticoagulant
– but the blood will coagulate when the temp increases
• Vigorous stirring of blood
– will cause the fibrin to adhere to the stirring rod and prevent
coagulation
– Continuous agitation will also prevent coagulation by causing the
fibrinogen to precipitate out as fibrin
– but this process damages the red blood cells
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Blood collection - cooling
• Refrigeration
– To minimize microbial growth
– Chilled as rapidly as possible after collection to
2~3C (35~40F)
• Caution
– Over-chilling can cause hemolysis of red celldifficult to separate from plasma and will result in
an off-color plasma.
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Blood collection - Separation
• Whole blood-plasma and red cell
• Separated as soon as after collection (within 20
min)
• accomplished by centrifugation
– 14000 rpm (continuous)
– 58000 rpm (non-continuous) of 10 min
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The Quality of Separation
•
•
•
•
With minimal red cell damage
Prevention oxidative rancidity
Keep clean
No fishy flavor-oxidation of hemoglobin and high fat
content in plasma
• Poor color in plasma
• One hundred pounds of whole blood
• 60~67lb off white plasma (8% CP)
• 33~40lb deep red cell (32% CP)
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Sanitation
• Equipment must be designed to facilitate
cleaning.
• Sticking knives and receiving containers must
be rinsed and sterilized after each use.
• Cleaning in place (CIP) system may work
• Due to the gelling nature of blood, must be
rinsed and washed with cold water before
being given a 82℃ water for sanitizing.
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Good Hygiene during blood collection
• Maintaining good hygiene of the blood collection system is essential
• If good hygiene is maintained, the bacterial quality of the blood
should be less than 2,000 total plate count organisms per mL of
blood and remain constant for a few days if stored at a temp of 2°C.
• After being hygienically collected, in most cases, whole blood can
be stored for 4 days at 2°C before the bacterial count starts to
increase dramatically.
• Blood is often stored between 0 and 2°C, and a storage life of 4-6
days is possible.
• If strict hygiene standards are not followed, blood may have as
many as 2.5 × 105 organisms/ml of blood at collection and rapidly
increase during storage.
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Drying of blood
• In most plants, concentration is accomplished by
evaporation (some using membrane filtration)
• Steps
– 1. evaporating → concentrated plasma
– 2. spray drying of the concentrated plasma
• plasma is atomized into minute particles and is immediately contacted with
a flow of hot air.
• Dried particles are 75 µm in size when drying is completed
– 3. Lowering salt conc
• When plasma is dried, it normally has a high-salt conc (due to the added
anticoagulant)?
• The salt content can be lowered by ultrafiltration of the concentrated
plasma.
•Blood should not be dried above 80C to maintain its functional qualities.
• Results
– When ultrafiltration and spray drying are used, a dried blood plasma
can be produced with 96.4% protein and 2.5% moisture.?
– The
erythrocyte fraction has appro 35% dry matter and can be dried
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without concentration.
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14
General Properties of Blood Fractions
• Blood
– is composed of cellular and liquid components.
– Blood = blood plasma + blood cells
• Blood plasma
– If anticoagulants are added and erythrocytes are removed by
centrifugation from liquid blood, then the remaining liquid is called
“plasma” and contains fibrinogen (protein).
• blood serum
– is obtained when blood coagulates, because the serum does not contain
fibrinogen.
– Blood serum = blood plasma – fibrin
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blood plasma
•
Blood plasma + heating (boiled for 15-20 min) → solidify (forms a gel,
similarly to an egg white).
•
As solidification occurs, the gel will entrap fat, and water is released from
the protein matrix. The volume expands, and the strength of the gel
increases with temp between 75 and 95°C .
•
The gel structure develops slowly, and it requires appro 1 hr of heating to
get a maxi gel strength at 90°C. Gel formation is linked with the
denaturation of the protein molecule, which occurs at a temp between 67
and 73°C.
•
As denaturation occurs and the peptide chain unfolds, new reactive areas
are exposed. Reactions between hydrophobic areas, the formation of -S-Sbonds and electrostatic interactions of charged groups occur on the surface.
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Utilization of blood plasma
• Blood plasma proteins, such as albumin and
globulins, are also good emulsifiers.
• Emulsification of fat in a sausage product by plasma
and its capability to retain the fat during heating of
the sausage
• casein is a better emulsifying agent than blood
plasma, but blood plasma is better than soy and meat
proteins.
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Uses of blood plasma
• Directly adding to a meat mixture
– When used in meat sausages, it will decrease shrinkage
and increase yield (appro. 4-5%), and the texture of the
finished product will become more rigid because of the
gelling properties of the plasma.
– If higher conc are used (usually no more than 2% plasma
protein is used), the effect on sausages may be a slightly
rubbery meat product.
– can also be incorporated into a brine used for pumping a
curing mixture into solid meat items.
• Up to 50% of the water in the curing mixture can be replaced with a
brine containing 4% blood plasma protein
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Uses of blood plasma
•
In bakery products
– has good foaming (equivalent to egg albumin) and leavening properties and
spray-dried plasma has been successfully used as an egg substitute.
– 2-6% substituted for bread flour in bread baking, and this addition gave a
significantly higher loaf volume.
– Increased levels of plasma darkened the crust and made the texture more open
and coarse, but 2% plasma seemed acceptable for odor and taste.
•
The addition of plasma also increases the protein quality.
– With 2% plasma protein powder added, the bread would contain 15% more
protein and approximately 75% more lysine.
– Angel food cakes can also be supplemented with various quantities of blood
plasma, and the ratio of 30% plasma, and 70% egg white has given an
acceptable flavor.
•
Also in meat analogue
– This textured plasma protein is produced by adding NaOH to the plasma,
adjusting the viscosity, and extruding the spinning dope into a coagulating bath
of acid and/or salt.
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Utilization of Hemoglobin
• When blood plasma is separated from the erythrocytes, the
major portion (60-70%) of the protein content remains in the
hemoglobin of the erythrocyte fraction.
• Hemoglobin
– undesirable dark red color when added to most foods > 1%.
– a good catalyst for oxidation of unsaturated fatty acids
• The main use of hemoglobin
– because of color
• such as black sausage, black pudding
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Utilization of Hemoglobin
• To reduce the dark color (lighten colors)
– bleaching with a solution of hydrogen peroxide (H2O2)
• starts with hemolysis of the erythrocytes by the addition of 7 volumes of
water to the erythrocyte fraction and by heating this solution to 70°C.
• A 3% H2O2 solution is then added, which oxidizes the hemoglobin to
almost colorless verdomethemoglobin. After the reaction is completed,
the temp is reduced to 30°C, and the surplus H2O2 is removed with a
catalase enzyme
• the decolored protein coagulates into small spheres of approximately 1-2
mm in diameter, which can be collected by filtering.
– Results
• The resulting material is bland in taste and insoluble in water
• When added to a meat sausage item, it behaves as an inert ingredient,
causes the sausage to become softer, and changes the sausage from a pink
to a reddish-brown or yellowish-brown color if added in conc of 10%.
• If added at levels of 1-1.5%, the flavor and taste of the sausage is only
slightly affected.
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Blood serum for lab use
• Blood serum
– Fibrin-free blood plasma that is obtained after blood coagulation
– Usually obtained in the sterile form for lab use (be careful to avoid
contamination)
• Processing
– After collation, blood is chilled and clotted → cut into cubes → serum
separated (first 2-3 hr rejected, why?) → centrifuged (200-250g for
30 min) → deactivated by heating for 30 min at 55C → sterilized by
filtering →stored under refrigerated, frozen, or freeze-dried
• Uses
– As a medium in virus propagation
– In production of virus vaccine
– In bacteriological media
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Blood albumin
• “dried blood serum”
• Qualities
– Straw colored, soluble in warm water and coagulates at
70C
– Containing 80% protein, 5% moisture, and 15% salts
• Uses
– A substitute for dried egg albumin in food
– Providing a gloss to leather finishes
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Spray-dried blood
• “Dark blood albumin” or blood powder
• Characteristics
– A water-soluble dark reddish brown powder
containing 5-8% moisture, 10-15% ash
• Uses
– Adhesive
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Blood meal
• Characteristics
– a dark-brown, dry (5-8% moisture) granular product
produced by drying whole blood or the heavy component
removed during recovery of blood plasma or serum.
• Uses
– Blood meal is used in calf starter rations, swine, and
poultry feeds.
– It is less digestible than meat meal.
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• Manufacturing
– The yield of blood meal from whole blood is appro 20%.
– blood run through a decanter to separate the coagulated
blood into pre-dewatered blood meal and blood water,
which is released during coagulation. The blood meal is
then cooked in a double boiler (or jacket) or by direct steam
injection with stirring to avoid clumping. It can also be
cooked in a vat over an open flame with constant stirring.
Lime (70% calcium oxide, CaO) is sometimes added at the
0.5-1.5% level to increase storage life and to decrease the
odor released during drying. Blood mixed with lime has a
rubbery consistency and can be stored at 20°C (68°F) for
24 hours without spoilage. It contains 15-20% solids and is
80-85% moisture. The dark-brown cooked product
(crumbly consistency) is pressed to remove moisture and
sun-dried or baked (with or without forced air circulation)
at 60°C to the desired moisture level. The dry rendering
process can also be used to dry the product. The dried
product is then ground and used as feed (80% protein) or
fertilizer (12% nitrogen, 0.22% phosphorus, and trace
elements). It is usually mixed with super phosphates to
make a compounded fertilizer. If calcium is used in the
production, this will also help to control the pH of acidic
soils. Spray-dried blood can also be used as an adhesive, in
asphalt emulsions, in insecticides, in ceramics, and as a
substitute for egg albumin when color is not important. The
dried product is often heated to 100°C (212°F) for 30
minutes, cooled, and stored in airtight containers to
increase storage life.
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