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Effects of dwell time and pressure during hot-pressing on wheat flour tortilla properties. J. L. ADAMS
and R. D. Waniska. Texas A&M University, Cereal Quality Lab, 2474 TAMUS, College Station, TX
77843-2474 USA.
Processing parameters of the hot-press were varied in the production of
wheat flour tortillas. Combinations of 750, 1100, and 1450 psi and 1.15, 1.35, and 1.55 s were used. Dough
and tortillas were prepared using laboratory-scale, commercial equipment and tortillas were evaluated
during storage at 22°C. Weight, moisture, and pH were not affected. Diameter and thickness of tortillas
were directly related to hot-press conditions. Larger diameter and thinner tortillas were produced using
higher pressure and/or longer press times. Thicker tortillas were produced at 750 psi (all press times) and at
1100 psi (1.15 s). Volume of tortillas was similar except when the extreme low pressure and dwell time
were utilized where a low diameter and volume were observed. Opacity of tortillas was similar except when
extreme low or high pressure and dwell time combinations were utilized. Shelf stability of tortillas was
improved in all high-pressure treatments. Thicker tortillas corresponded to shorter shelf stability. Force to
extend tortillas increased during storage for all treatments. Tortillas pressed for the longest time (1.55 s) at
intermediate and high pressure had the greater extensibility force and modulus values on the 12th day of
storage. Changes in the dwell time and pressure of the hot-press yielded tortillas with substantially different
attributes. Optimal thick tortillas were yielded by a low pressure for a long dwell time, while optimum thin,
large diameter tortillas were yielded by high pressure for an intermediate dwell time.
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