A cost-effective, faster and efficient way of screening wheat samples suitable for
tortilla production is needed. Hence, we developed prediction models for tortilla quality
(diameter, specific volume, color and texture parameters) using grain, flour and dough
properties of 16 wheat flours. The prediction models were developed using stepwise
multiple regression.
Dough rheological tests had higher correlations with tortilla quality than grain
and flour chemical tests. Dough resistance to extension was correlated best with tortilla
quality, particularly tortilla diameter (r= -0.87, P<0.01). Gluten index was significantly
correlated with tortilla diameter (r = -0.67, P less than 0.01) and specific volume (r = -0.73,
P less than 0.01).
Tortilla diameter was the parameter best predicted. An r2 of 0.87 was obtained
when mix-time and dough resistance to extension were entered into the model. This
model was validated using another sample set, and an r^2 of 0.91 was obtained.
Refined and whole wheat flours, dough and tortillas were compared using five
wheat samples. Refined flour doughs were more extensible and softer than whole wheat
flour doughs. Whole wheat flour tortillas were larger, thinner and less opaque than refined flour tortillas. Refined wheat flour had much smaller particle size and less fiber
than whole wheat flour. These are the major factors that contributed to the observed
differences. In general, refined wheat tortillas were more shelf-stable than whole wheat
tortillas. However, whole wheat tortillas from strong flours had excellent shelf-stability
which must be considered when whole wheat tortillas are processed. .
Different objective rheological techniques were used to characterize the texture
of refined and whole flour tortillas during storage. Differences in texture between 0, 1
and 4 day-old tortillas were detected by rupture distance from one and two-dimension
extensibility techniques. In general, the deformation modulus was not a good parameter
to differentiate tortilla texture at the beginning of storage. It detected textural changes of
8 and 14 day-old tortillas. The subjective rollability method detected textural changes
after 4 days storage.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-05-755 |
| Date | 2009 May 1900 |
| Creators | Ribeiro De Barros, Frederico |
| Contributors | Rooney, Lloyd W. |
| Source Sets | Texas A and M University |
| Language | English |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | application/pdf |
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