Meat emulsions - batters
– Frankfurters are the best example
-produced with unique technology that is highly protein
dependent
-failures, i.e. “broken” emulsions are a dramatic mess
(fat caps where separated fat rises to upper ends of the
frankfurters as they hang on smoketrucks during
cooking, then solidifies into solid fat when chilled)
-successful, i.e. stable emulsion/batter is the result of 3
factors:
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
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”
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
protein
fat
water
fat
Proteins rearrange
somewhat and
consequently lose some
water binding ability
(know this)
Therefore there are three necessary
components for every emulsion/batter
– internal phase
i.e. fat
– external phase
i.e. water
– emulsifier
i.e. protein
“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
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
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
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
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
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
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)
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)
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
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
6. Vacuum processing
– Chopping/mixing under vacuum can increase
capacity and stability
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
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)
7. Stuffing
– Pressure flow of product, proper casing diameter
– minimize smear/separation of fat and breaking
emulsion membranes prior to heating
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
Remember:
– “Bind” values listed for calculating formulations
with different meat ingredients reflect water
and fat binding ability
Ex.
Bull meat
Pork picnics
50 pork trim
Liver
Beef hearts
17.0
16.0
4.1
1.25
0.3