Development of Iranian rice-bran sourdough breads: physicochemical, microbiological and sensorial characterisation during the storage period

Rice bran (RB) as a functional by-product was used to develop healthy-nutrition breads. Moreover, the sourdoughs fermented by three lactic acid bacteria (LAB) including Lactobacillus plantarum, Lactobacillus delbrueckii and Leuconostoc mesenteroides were applied to reduce negative effects of RB on the quality characteristics of leavened bread. Physicochemical, microbiological and sensorial features of the breads by adding the different RB-sourdoughs (10%) were compared to control bread during storage time. Results showed that L. plantarum and L. delbrueckii had a similar behaviour in reducing the pH and titratable acidity in the breads and sourdoughs. A firmer crumb was observed due to low moisture content in the control compared with the breads prepared from three LAB at the end of storage time (P<0.05). The loaf volume of breads obtained from sourdoughs fermented by L. mesenteroides was significantly higher than the control bread. Microbiological assays revealed that growth rate of Aspergillus niger and Penicillium italicum can be significantly retarded by the application of each of three type of RB-sourdoughs. Although overall acceptability of the control bread was comparable to the sourdough breads until fifth day of storage, it was significantly lower than other breads on the seventh day.