Abstract
The effects of mixtures of 0.5% calcium carbonate (CaCO3) and 0-1.0% magnesium salts (MgCl2 or MgSO4) on the thermal and rheological properties of 47.6% non-glutinous rice flour dough were investigated by measuring the DSC characteristics, X-ray diffraction patterns, storage moduli and loss moduli of dough samples, and by observing SEM images. Unheated dough containing a mixture of 0.5% CaCO3 and 1.0% of either magnesium salt showed greater linking of starch particles than that containing 0.5% CaCO3 alone based on the SEM observation. The water absorbed by heated dough was less after adding a mixture of 0.5% CaCO3 and 0.5% or 1.0% MgCl2 than dough containing 0.5% CaCO3 alone (p<0.05). Adding either MgCl2 or MgSO4 decreased the values of the rupture properties of unheated dough containing 0.5% CaCO3. The rupture stress and rupture energy of heated dough containing CaCO3 and the figures for dough containing CaCO3 soaked in ionized water were both increased by adding either MgCl2 or MgSO4.
