412 Chapter 23
benefi cial effect on color; and (3) processing
factors, such as boning time (hot versus cold),
rigor state (pre - versus postrigor), particle
size reduction, blade tenderization, tempera-
ture, pressure, and packaging (Hunt and
Kropf 1987 ). Color problems in restructured
meats are related to the method of restructur-
ing and the type of binder used. The color
and overall appearance of raw slices of beef
rolls restructured using Activa TM binding
system were preferred over those restructured
using the alginate binding system (Farouk et
al. 2005b ). Color and appearance problems
may not be as important in hot - set restruc-
tured products, since they are likely to be sold
in cooked or frozen form compared with
cold - set restructured products that could be
sold uncooked and/or chilled. For instance,
consumers in a previous study found the
color of cooked hot - set restructured roast
beef prepared from nonuniform colored raw
material (including prerigor, postrigor, grass -
, and grain - fi nished beef) equally acceptable
(Farouk and Swan 1997 ). The use of nonuni-
form - colored meats, as in the study by Farouk
and Swan (1997) , or mixing high - and nor-
mal - pH meats or muscles with predominantly
white fi bers and those with red fi bers, or
restructuring meats with fi bers aligned at dif-
ferent directions to the cut surface of steaks,
can all result in the reduced acceptability of
cold - set raw restructured meat products. The
appearance of the steaks shown in Figure
23.5 is a good example of an aesthetic - related
problem. The cooked beefsteak does not look
natural because of the cross striations on the
steak caused by the alignment of muscle
fi bers parallel instead of perpendicular to the
surface of the steak during restructuring. The
offal steak had a mottled appearance and
looked like a jigsaw puzzle, due to the use of
raw materials of nonuniform texture and
color during restructuring.
The effect of fi ber alignment on the
appearance of restructured steaks was dem-
onstrated by Farouk et al. (2005c) in a study
in which raw restructured beef steaks withcomprised of a lean meat core and a fatty
outer layer through the following steps: (1)
slicing whole - muscle meat into small, thin
slices (the slices should be held just below
0 ° C); (2) the thin slices are then agitated and
mixed with a hot - set binder (meat - based
adhesive liquid) for about two minutes; (3)
the binder - coated slices are then loaded into
a coextrusion machine and pumped through
to the extrusion head; fat - forming fl uid
(emulsifi ed mixture of fat and meat) is also
loaded into the extruder and pumped to
another region of the extrusion head; (4) the
coated slices and the fat - forming fl uid are
coextruded in the desired shape onto a
moving conveyor; (5) the coextrudate is then
conveyed through an elongate freezer to be
crust frozen into a partially frozen log that is
cut into pieces of desired thickness; (6) the
sliced pieces are then fi nally frozen.
Quality Problems of Restructured
Whole - Tissue Meats
The common objective of restructuring is to
achieve a product that not only imitates but
also possesses the attributes of a whole - tissue
product, including: aesthetic - related attri-
butes (color, appearance, and overall visual
appeal); oral - related attributes (texture and
tenderness); and other sensory related attri-
butes (fl avor and aroma/odor).
Aesthetic - Related Quality Problems
Color and appearance are important factors
in consumers ’ point - of - purchase decisions.
An undesirable color reduces the acceptabil-
ity of restructured meats and is a major
problem for manufacturers (Hunt and Kropf
1987 ). The factors that affect the color of
restructured meats include: (1) raw material
condition, such as the oxidative - reductive
state of the meat used in restructuring, meat
pH, and microbiological condition; (2) ingre-
dients, such as the level of salt and its nega-
tive effect on color, and phosphates and their