The thermal properties of wet nixtamalized masa are important during the cooking phase of the tortilla production process. These properties are unique for each material and are affected by the chemical composition and additives supplemented. In this study, effects of pericarp and non-polar lipids extracted from maize grain, and xanthan gum added to traditional wet nixtamalized masa, were examined for thermal diffusivity, conductivity and effusivity, heat capacity, gelatinization temperatures and enthalpy. Components and additives added separately to wet masa were: 1.5%, 3%, 4.5% and 6% (w/w, db) of maize pericarp; 0.5%, 1% and 2% (w/w, db) of non-polar lipids; and 0%. 0.1%. 0.2% and 0.3% (w/w, db) of xanthan gum. The results were compared with those of wet masa and tortillas without additives. Based on results, the best thermal properties were obtained from tortillas of nixtamalized maize masa supplemented with 4.5% (w/w, db) pericarp, or with 0.5% (w/w, db) non-polar lipids, or with 0.1% (w/w, db) xanthan gum. (c) 2006 Elsevier Ltd. All rights reserved.