ABSTRACT
A high-amylose, non-floury corn, a floury corn, and a 1:1 blend were made into masa and then tortillas. The masa flour made with the high-amylose corn had a greater amount of resistant starch (RS 28.8%) and a greater amount of total dietary fiber (TDF 42.1%) than that with the floury corn (RS 2.9%, TDF 9.6%), producing a high-fiber tortilla. The masa was evaluated for pasting properties using a Rapid ViscoAnalyser (RVA). The high-amylose masa slurry gelatinized little at 95°C. The floury masa had the greatest peak viscosity, whereas the 1:1 blend was intermediate in value. Sensory evaluations of the tortillas for the textural attributes showed the floury tortillas to be chewier, more rollable, and grittier than the high-amylose tortillas, whereas the blend tortillas were intermediate for most attributes. The cutting force of the high-amylose tortillas, measured on a texture analyzer, was very low; the blend and floury tortillas required more force. Chewiness was correlated to rollability (r = 0.99, P = 0.05). The %RS and %TDF were correlated to rollability (r = –0.99), and cutting force (r = 0.99). The floury and blend tortillas had firm textures expected of desirable tortillas, whereas the high-amylose tortillas broke under little force, and would not roll. The high-amylose tortillas had high amounts of RS and TDF but poor texture. The blend tortillas retained most floury tortilla textural properties, making them suitable products for consumer use.
