Study of staling phenomenon ingluten-free bread prepared from Iranian rice flour cultivars

Staling of the bread prepared from the flour of various kinds of newly developed rice cultivars (Tarom, Shiroodi, Neda, Fajr, Ghaem and Binam) was investigated. To prepare free gluten bread, rice flour with 2% hydroxylpropylmethylcellulose (HPMC) as gluten substitute were used. Moisture content, enthalpy changes (ΔH) and firmness of bread were monitored and found to be significantly affected during storage at room temperature. Crumb moisture content was found to decrease steadily during staling and crust moisture content increase during storage time. Enthalpy changes (ΔH) as measured by differential scanning calorimeter (DSC) increased over the time in Binam, Fajr, Tarom, Shiroodi and Neda cultivars. Ghaem, Binam and Tarom cultivars had lower amylose content than the others and showed lower values of ΔH. Staling of gluten-free rice bread results in increasing firmness of crumb and decrease firmness of crust, therefore, the crumb texture of this bread became progressively harder with storage. The lowest value of crumb firmness was reported for Binam cultivars in four days of storage.