Meat emulsions - batters

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Meat emulsions - batters

• frankfurters are the best example
• produced with unique technology
• highly protein - dependent
• failures i.e. broken emulsions are a
  dramatic mess
• successful i.e. stable emulsion/batter is
  the result of 3 factors

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Emulsion/batter stability is determined by

• 1. Meat quality
• meaning - myofibrillar protein content and
  functionality
• quality problems like PSE pork can result in
  emulsion/batter problems
• WHC and fat binding
• 2. Handling knowledge and technology
• meaning - appropriate use of salt, temperature,
  added water and chopping to properly manage
  soluble protein and dispersed fat
• 3. Additional binders to help stabilize
  emulsion/batters and control physical properties

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Before we cover specifics --- some definitions

• emulsion - stable dispersion of one immiscible
  liquid in another
• i.e. water-in-oil (mayonnaise, butter)
• oil-in-water - frankfurters
• 30 fat is well-hidden
• true emulsion
• dispersed particle size is 0.1µ or less
• meat emulsion - particle size is typically 1.0 µ
  or more therefore often called a batter

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What is fat binding?

• 1. Fat cell walls
• intact cells retain fat
• dried cells i.e. salted can be very stable
  due to collagen/cell wall rigidity and
  impermeability
• 2. Emulsification membranes
• myofibrillar proteins
• hydrophobic portion ? fat
• hydrophilic portion ? water

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protein
fat
water
Proteins rearrange somewhat and consequently lose
some water binding ability
fat
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Therefore there are three necessary components
for every emulsion/batter

• internal phase
• i.e. fat
• external phase
• i.e. water
• emulsifier
• i.e. protein

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Membranes are critical to raw emulsion/batters
-- but cooking then results in

• 3. Heat-set gelation - crosslinking proteins to
  form a 3 dimensional matrix
• semi-rigid trap for fat and water
• critical to cooked stability, texture, slicing,
  appearance

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More definitions

• Emulsion/batter capacity
• maximum amount of fat or oil stabilized by a
  given amount of protein
• measured by oil-in-water dispersion with clear
  blender jar, colored oil, protein solution
• model system comparisons
• emulsion/batter stability
• amount of fat or oil retained (or separated)
  after stressing, usually with heat, a formed
  emulsion/batter
• practical comparisons
• affected by process technology and non-meat
  ingredients

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Factors affecting stability can be found in
Stokes Law
V D2(de-di) k vis

• D diameter of fat globules
• de density of external phase
• di density of internal phase
• k constant
• vis viscosity

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Practically V D2
vis

• smaller fat globules are more stable (also
  require more protein)
• greater viscosity (protein solubility, protein
  quality, temperature, non-meat ingredients, salt
  concentration) is more stable

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Processing parameters

• 1. Start with lean meat plus salt
• best at 4-5 (brine strength)
• plus ice/cold water
• temperature control
• increased protein solubility and swelling
• can chop or mix (extract) longer
• low temperature increases viscosity

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2. Chopping/mixing

• two effects
• a. dissolves (1-5) and swells (remainder) of
  myofibrillar protein
• b. breaks fat cells and subdivides fat into small
  globules
• chopping needs to be extensive enough to achieve
  small fat globules with solubilized protein
  membrane coatings
• over chopping will destroy the protein membranes
  and break the emulsion/batter
• usually chop lean, salt, water to about 40oF

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Critical considerations

• chopper speed
• sharp knives
• bowl/knife clearance
• temperature control and monitoring
• add fat meat at 40oF and chop to 55oF (pork fat),
  65oF (beef fat)

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3. pH is critical

• Protein functionality is closely related to the
  pH - WHC curve / relationship
• therefore increasing pH increases emulsion
  stability
• pre-rigor meat is 50 - 100 more effective than
  post-rigor
• phosphates are important
• pre-blends (lean meat salt 1/2 nitrite) are
  very effective (and advantageous for cured color
  as well)

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4. Collagen

• High collagen meat sources are a potential
  problem
• high capacity, low stability
• forms membranes but converts to gelatin when
  heated
• however, ground/powdered collagen appears to be
  effective probably depending on adequate
  dispersion followed by gelatin formation

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5. Other emulsifier proteins

• myofibrillar proteins might be best saved for
  WHC and gelation
• pre-emulsions --- use another protein to coat
  fat globules --- then add pre-emulsion as fat
  to meat mixture
• soy and caseinate
• skin / collagen is sometimes used

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6. Vacuum processing

• Chopping/mixing under vacuum can increase
  capacity and stability

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6. Vacuum processing

• microscopic observations show air bubbles
  probably surrounded by protein thus consuming
  some protein functionality
• air competes with fat for the emulsifier making
  the emulsion/batter less stable
• more critical for round globular sarcoplasmic
  proteins than for filamentous, long myofibrillar
  proteins

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6. Vacuum processing

• product density and diameter will differ with
  vacuum
• can contribute plumpness
• major effects on cured color development
• with about 50 ppm in going nitrite vacuum will
  give good cooked color while non-vacuum will give
  gray cooked color
• absence of air also will decrease likelihood of
  rancidity development
• not as much an issue in cured meats as for fresh
  products (i.e. pork sausage)

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7. Stuffing

• Pressure flow of product, proper casing diameter
• minimize smear/separation of fat and breaking
  emulsion membranes prior to heating

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8. Heating / cooking

• humidity
• important to yields, thus is kept high --- only
  risk is high collagen content
• heating rate
• critical to proper protein gelation
• protein unfolding ? crosslinking ? gel formation

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Remember

• Bind values listed for calculating formulations
  with different meat ingredients reflect water
  and fat binding ability
• Ex. Bull meat 17.0 Pork picnics 16.0 50
  pork trim 4.1 Liver 1.25 Beef hearts
  0.3

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