EFFECT OF LIME CONTENT ON THE PROCESSING CONDITIONS OF COOKED MAIZE TORTILLAS - CHANGES OF THERMAL, STRUCTURAL, AND RHEOLOGICAL PROPERTIES

Basic data on thermal, dielectric, and IR spectral properties of cooke d tortillas were investigated with the major aim to understand the rol e of lime, Ca(OH)(2), incorporated during the alkaline cooking process . The data are further supplemented by x-ray diffraction and texture m easurements. The changes in the thermal diffusivities, measured by the photoacoustic technique, as well as the changes in texture, x-ray pat terns, dielectric, and IR spectral properties are presented as a funct ion of the lime concentration. The results show strong evidence that t here is a marked concentration of lime (around 0.2%) above and below w hich different behavior patterns of the measured properties of tortill a were observed. in particular, the results for the dielectric constan t and thermal diffusivity provide strong evidences for enhanced starch crosslinking taking place for lime content close to 0.2%. (C) 1997 So ciety of Photo-Optical Instrumentation Engineers.