Optimization of fermentation conditions in Barbari bread based on mixed whole flour (barley and sprouted wheat) and sourdough

Abstract

The purpose of this study was to use a mixture of whole wheat–barley flour mixture in the preparation of traditional Iranian bread (Barbari) in the optimum condition of fermentation to benefit from all available nutrients. In this study, bread parameters such as specific volume, porosity, textural characteristics, zinc, iron, phytic acid and organoleptic properties were investigated. In this research, different percentages of sourdough (15–30%) and fermentation time (30 – 120 min) were applied. Results showed that the phytic acid content significantly decreased ( p < 0.05) (0.23 – 0.14) by increasing sourdough and fermentation time, which result in increasing in zinc (17.49 – 22.89%) and iron (36.44 – 45.32%) content. Both the sourdough content and fermentation time parameters had a significant effect ( p < 0.05) on the better porosity (9.05 – 13.50%) and overall acceptability of bread (2.15 – 3.85). The hardness, gumminess, chewiness, porosity, phytic acid and overall acceptance parameters were used to optimize the fermentation conditions of Barbari bread by response surface methodology using a central composite design. Optimal conditions for the production of Barbari bread were 29.53% sourdough and 120 min fermentation time. Under optimal conditions, the overall acceptance, hardness, porosity, chewability, gumminess and phytic acid were 3.84, 60.81 N, 14.09%, 302.01 N/mm, 41.37 N and 0.15%, respectively.