evaluation of additional carboxy methyl cellulose and k-carrageenan gums on the qualitative properties of gluten- free toast breads

in this research, after carrying out chemical tests measuring the moisture, protein and ash contents on rice flour according to standard methods, gluten- free breads were prepared from rice flour combined with 0.5% carboxy methyl cellulose (cmc) and 1% -κcarrageenan gum. a sample lacking gum was also produced as control. rice breads (with gum and without gum) were then produced by semi-industrial method. dough and bread yield assays as well as voltmeter were carried on the obtained breads. the results showed that the addition of two gums led to the improvements of dough and bread yield properties as well as specific volume as compared to the control sample with 1% cmc that resulted in a more specific volume and 1% k-carrageen that gave a better dough and bread yields. chemical tests measuring the moisture, ash and protein contents were performed on all bread samples followed by the determination of staling rate through instrumental method (instron machine) according to the standard methods. the results of chemical tests carried on wheat flour and rice flour showed that consumed flour was suitable for toast bread making. the results of chemical tests carried on produced bread sample showed that k2 treatment had the highest moisture content; kc treatment had the most ash content; control treatment 1(w) showed the highest protein followed by kc treatment and rice control treatment (c) had the lowest amount of moisture, ash protein. the results obtained from staling rate test instrumentally at time intervals of 24, 48 and 72 hours after baking showed that at three time intervals c treatment had the highest staling rate, and w, k2 and c2 treatments had the lowest staling rate respectively. the obtained rice breads were presented to a group of panelists to assess the sensory properties including porosity and granular appearance of the bread crumb, aroma, color of crumb, chewiness and texture as well as staling property. the results obtained from the sensory analysis indicated that the addition of two gums led to improvement of sensory properties of gum containing samples as compared to the control- of among gum- containing samples, bread with 1% cmc had the best sensory properties.