Barley for Food and Health: Science, Technology, and Products

OBJECTIVE EVALUATION 139
Muffin quality factors are even grain, absence of tunnels, shape, and symmetry.
Muffins from different formulations can be tested for volume comparison
using the rapeseed displacement method cited earlier. Photocopies or photographs
can be used to visually evaluate cell structure and the presence of tunnels, and
also to compare shape, such as peaks or knobs on the top. Quick loaf breads
are evaluated similarly to yeast breads but with more emphasis on texture and
compressibility. In the United States, biscuits are rich, flaky, chemically leavened
small breads, whereas the term biscuits in the United Kingdom refers to
products known as cookies in the United States. Evaluation of American biscuits
involves volume, tenderness, and texture, according to methods cited previously
for breads (Penfield and Campbell 1990).
Cake quality is assessed by volume, texture, and compressibility. The consistency
of cake batter can be measured as a prediction of quality in the final
product, using line spread measurements or the use of devices such as a viscometer
to measure viscosity or consistency. Volume measurement, the determination
of volume index, is an important quality factor for cakes. Approved Method 10-91
(AACC 2000) provides templates for measuring cakes and evaluating symmetry.
Appearance of the grain in cake is often used, similar to that used in evaluating
the grain in yeast bread. Compression testing for crumb firmness or softness,
described previously, is appropriate for cake. Approved Method 10-50D (AACC
2000) for cookie dough quality measures spread ratios, giving an indication of
final size and thickness uniformity. The Bailey Shortometer (Computer Controlled
Machines, Northfield, Minnesota) measures the force required to break
a cookie placed across horizontal bars. Universal Testing Machine instruments
may also be used to measure texture in cookies (Penfield and Campbell 1990).
Evaluation of Pasta
Durum wheat is the raw material preferred for the production of pasta. In commercial
practice, a durum mill produces semolina flour. By definition, semolina is
the fraction of milled durum remaining on a U.S. No. 100 sieve in a standard test.
Flour evaluation for making pasta is generally based on kernel quality, milling
performance, and end-product quality (Dick and Youngs 1988). The cooking
quality of pasta is related to the quality and quantity of protein in the endosperm,
and 12% protein is generally required. Any pasta product containing a partial substitution
of an alternative grain such as barley is still dependent on the quality of
the original wheat, particularly the gluten strength. The gluten strength of durum
is measured by techniques similar to those used for bread dough: namely, use
of a mixograph or farinograph. In addition, a microsedimentation test is utilized,
which measures how much a ground meal swells in a sodium dodecyl sulfate
and lactate solution (Dick and Youngs 1988).
In the United States, pasta products are evaluated by color, cooked weight,
residue in the cooking water, firmness, and sample scoring. Color analysis usually
employs the Hunter Lab color meter as well as other models that allow detection
of red or brownish tones, considered undesirable. The cooked weight procedure