Resumo

MORENO-CASTRO, L.E. et al. Nixtamalization assisted with ultrasound: effect on mass transfer and physicochemical properties of nixtamal, masa and tortilla. Rev. Mex. Ing. Quím [online]. 2015, vol.14, n.2, pp.265-279. ISSN 1665-2738.

The effects of ultrasound during maize nixtamalization at different temperatures on the properties of nixtamal, masa and tortilla were evaluated. White maize; was nixtamalized at 85 and 95 °C, with and without ultrasound (843 W-m^-2). Pericarp removal, the water and calcium absorption kinetics, and the apparent diffusion coefficients (D_A) from Fick's second law, the thermal and structural properties of the nixtamalized flours and thee texture of the masa and tortillas were; determined. The ultrasound and temperature affected significantly the water and calcium absorptions kinetics, showing linear and asymptotic tendencies during cooking and steeping , respectively. These were described adequately by Fick's model, and the ultrasound significantly increased the D_A of water (2.54-3.93x 10^-10m².s^-1). Over 80% of the pericarp was removed during cooking. The gelatinization enthalpy showed a decreaseat 95 °C. Microscopy images showed spherical and polygonal granules at 85 °C, and a shape loss with increasing diameter by ultrasound effect (95 °C). Nixtamalization assisted by ultrasound reduced the processing time compared with traditional or industrial process.

Palavras-chave : nixtamalization; ultrasound; calcium; texture; tortilla.

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