Emulsifi cation 147less binding properties. Different kinds of
meat — beef, pork, veal, poultry — can be used
in fi nely comminuted products. Beef has the
highest binding properties compared with
pork or poultry, but pork is often used (Heinz
2007 ).Infl uence of Processing Treatment
High pH or the addition of NaCl or polyphos-
phates prerigor decrease the actine - myosine
interaction and thus increase the swelling
capacity. Prerigor meat is known to have
higher water - holding capacity (WHC) and
better fat emulsifying properties than
postrigor meat; it is thus better suited to make
comminuted meat products such as sausages
(Hamm 1982 ; Calderon 1984 ; Bentley et al.
1988 ; Claus and Sorheim 2006 ). This is due
to higher pH and ATP level (Pisula and
Tyburcy 1996 ).
The high level of ATP in prerigor muscle
inhibits the interactions between actin and
myosin and creates a loose network able to
absorb water. During rigor, the ATP degrada-
tion releases divalent ions (Ca++ and Mg++),
which favor bridges between proteins,
leading to a tight network. During the later
maturation, bridges between actin and myosin
can be broken and WHC can increase
(Calderon 1984 ).
At high pH, above the isoelectric point,
the WHC is maximum. After 24 hours post-
mortem, pH decreases due to lactic acid for-
mation ’ s tendency toward the isoelectric
point. Due to the decrease of electrostatic
repulsion, the protein network tightens, and
WHC drastically decreases. Moreover, it was
found that emulsion stability increases at
high pH, particularly for myosin (Denoyer
1978 ). HLB (Hydrophile Lipophile Balance)
meat protein values increase with muscle pH:
HLB equals 14.5 for proteins in the prerigor
state, whereas HLB equals 13 to 13.5 for
proteins in the postrigor state (Girard 1990 ).
An alternative method to keep a high
water - holding capacity is to use freezing orinsoluble even in solutions of high salt con-
centration constitute the stromal fraction.
The main ones are elastine and collagen con-
tained in the connective tissue. Proteins that
are soluble in water or dilute salt solutions
constitute the sarcoplasmatic fraction. There
are around fi fty sarcoplasmatic proteins,
which represent 30% to 35% of the total
muscle proteins. They have very weak
binding properties, but they participate to sta-
bilize the emulsion by lowering the interfa-
cial tension between aqueous phase and lipid
(Calderon 1984 ). Among them, myoglobin is
the most abundant. Proteins that are soluble
in more concentrated salt solutions constitute
the myofi brillar fraction. They play the most
critical role during meat processing, as this
fraction is responsible for the structure build -
up and the resulting texture of meat products
(Culioli et al. 1993 ; Xiong 1997 ; Zayas
1997 ). They represent more than 50% of the
muscle proteins (Cheftel 1985 ). Their func-
tionality is based on their ability to form
three - dimensional viscoelastic gels, bind
water, and form cohesive membranes at the
oil/water interface of emulsions or fl exible
fi lms around air bubbles. Actin, myosin, and
actomyosin are responsible for most of
the functional properties of meat; they con-
tribute to approximately 95% of total water -
holding capacity of the meat tissue and
75% – 90% of the emulsifying capacity (Li -
Chan et al. 1985 ). Among them, myosin
is the most important for fat emulsifi cation
and water - holding capacity (Galluzzo and
Regenstein 1978 ; Xiong 2000 ). The superior
emulsifying properties of myosin are believed
to be the result of the concentration of hydro-
phobic residues in the head region, the hydro-
philic groups in the tail region, and the high
length - to - diameter ratio promoting protein -
protein interaction and molecular fl exibility
at the interface (Xiong 1997 ). Meat func-
tional properties depend on the type of meat
muscle, species, and pH. Binding properties
decrease with the decreasing skeletal muscle
content of the meat used. Low pH meats have