Study of the possible formation of calcium cross-links in lime treated ("nixtamalized") corn

The possible formation of calcium cross-links in lime-cooked ("nixtamalized ") corn was investigated. A 2(3) factorial design was utilized, with the fo llowing independent variables: lime (calcium hydroxide) dose, 1 and 3%, bas ed on dry corn weight; cooking time, 1 and 2 h; and postcooking holding tim e, 0 and 18 h. All samples were rinsed, air-dried, and ground in a hammer m ill with a 40-mesh screen, and the corresponding viscoamylograms obtained. An untreated and milled (40 mesh) raw corn sample was used as control. Depe ndent variables were viscosities corresponding to attainment of maximum and minimum temperatures (95 and 50C) and end of holding periods at the same t emperatures. Viscosities increased with increasing lime dose, decreased wit h increasing cooking time and were unaffected by holding time. These observ ations suggested that calcium cross-links were probably formed, and that de gree of cross-linking increased with increasing lime dose (1 to 3%), and al so with increasing cooking time (1 to 2 h).