Modelling of cooking of wheat to produce bulgur Original Research Article

Three gelatinization measuring methods i.e. centre cutting, light scattering and amylose/iodine, were used to control the cooking of wheat (Triticum durum) for bulgur processing. Nonlinear models (Sigmoid, Logistic, Gompertz, Hill and Chapman models) were also derived to describe the cooking operation using centre cutting, light scattering and amylose/iodine values, and deformation degree of the intact wheat kernel. The best fitting models obtained were the Sigmoid (r2 = 0.989, RSS = 11.758, P < 0.05), Chapman (r2 = 0.998, RSS = 4.536, P < 0.05) and Gompertz (0.999, RSS = 3.905, P < 0.05) for centre cutting and light scattering, amylose/iodine and deformation degree, respectively. The optimum cooking time for wheat was determined as 40 min at 100% gelatinization without any deformation on the wheat kernel. The obtained cooking degree from amylose/iodine method was higher than the centre cutting and light scattering methods up to 40 min due to differences in measuring procedures of each method. After this time, the three methods gave same the cooking degree value.