Effects of different concentrations of guar, xanthan and locust bean gums on physicochemical quality and rheological properties of corn flour tarhana
Özet
Purpose Celiac disease patients cannot consume gluten-containing diets; thus, gluten-free products should be offered to meet the nutritional needs of these patients. The purpose of this study was to produce gluten-free tarhana for celiac disease patients using corn flour instead of wheat flour and investigate some physicochemical properties of tarhana. Hydrocolloids were used to compensate for technological deficiencies caused by the absence of gluten. Design/methodology/approach Hydrocolloids including guar gum, xanthan gum and locust bean gum were added at concentrations of 0.5% and 1.0% to the corn flour. The substituted corn flour samples were used to produce tarhana powder. Findings The pH and acidity measurements were carried out in 0th, 24th and 48th h of fermentation, and for all samples, the pH gradually decreased during fermentation, whereas the acidity increased. According to the color measurements (L, a and b values), it was observed that there was no significant difference (p = 0.588) between the gums in terms of L values in tarhana dough samples. Water retention capacity values of control, guar gum 1%, xanthan gum 1% and locust bean gum 1% were found to be 1.1, 1.1, 0.7 and 1.2 mL/g, respectively. The viscosity measurements were carried out at three different temperatures (30 degrees C, 45 degrees C and 60 degrees C), and the viscosity values were found to decrease significantly (p = 0.000) with the increase in temperature for all the samples studied. The highest viscosity values were obtained by 1.0% xanthan gum (4,333 mPa s) and 0.5% locust bean gum (3,575 mPa s) added tarhana samples for 3 rpm at 30 degrees C. Xanthan gum addition showed the lowest foam capacity values (0.04 mL/mL) among the samples. The samples with guar gum, xanthan gum and locust bean gum are recommended with regard to consistency and foam stability in the production of tarhana. Originality/value This study confirms that the use of gums in tarhana, a gluten-free system, is beneficial for the technological aspect. The unfavorable properties that can be seen because of the absence of gluten in corn flour tarhana can be compensated with the use of hydrocolloids, and tarhana can be recommended to celiac disease patients.
