Flat bread baking: Single to double layer transition

Abstract

Double-layered flat bread features an impressive oven rise and delamination during baking, leading to the formation of an internal pocket capable of holding various solid foods – a key quality criterion for consumers. These breads are unique in their baking method, which requires specialized ovens and high temperatures between 350 and 550 °C. Use of high baking temperatures to achieve the double layering development (called delamination) during baking has raised concerns over excessive energy consumption. In this study, whether or not the application of fermentation (affecting the accumulation of dissolved CO2) and baking temperature (which affects gas generation) were varied and the impacts on delamination were evaluated. To complement this evaluation, dough water content and temperature were monitored during baking. In a novel manner, this study characterized water distribution in flat bread, explaining the surprising decrease of water loss with increasing baking temperature. Our study has clearly shown water vapor to be the prime cause of delamination. The role of water pressure in dough inflation and in causing the edges to detach from the deck and the heterogeneity of flat bread water content were highlighted and a concept map proposed.