EVALUATION OF FOUR SORGHUM HYBRIDS THROUGH THE ...

gluten matrix can hold some of the steam and gas, but some enlarged air bubbles form
blisters that collapse after cooling.
Quality Assessment
Flour quality is important for producing an acceptable tortilla. The protein
content, ash content, starch damage, and moisture absorption of flours are typically
analyzed (Qarooni 1993). Color and particle size distribution can also help assess the
flour (Waniska and others 2004). Waniska (1999) claims the protein content alone is not
suitable in determining flour quality since protein contents ranging from 9.5 to 12.5%
have been found successful. The protein quality must also be taken into consideration.
Tortilla dough can be subjectively assessed for dough machineability and
stickiness (Bello and others 1991). Waniska and others (2004) used softness and
toughness scales to evaluate the doughs visco-elastic properties. Also, the dough mixing
properties were assessed using a mixograph.
The quality of the baked flour tortilla can be assessed subjectively and
objectively. Subjective characteristics include: toast spots, flexibility, puffing, streaks,
mouth-feel, layering, symmetry, aroma and flavor, and opaqueness (Bello and others
1991; Qarooni 1993; Cepeda and others 2000; Adams and Waniska 2005). Objective
attributes include: weight, diameter, thickness, moisture content, color and pH (Bello and
others 1991; Qarooni 1993; Cepeda and others 2000; Adams and Waniska 2005).
A final important assessment of flour tortilla quality is shelf-life. A shelf-life
evaluation may include an objective and/or subjective test. Objectively, tortillas are
evaluated utilizing a texture analyzer with extensibility being a typical test. The
rollability method is used for subjective assessment. The tortilla is rolled around a 1-cm
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