Cuisson de pain sous vide partiel à basse température

Abstract

International audienceAn experimental approach of partial baking of dough rolls at low temperature and under partial vacuum was developed. In contrast to previously applied vacuum to bread dough e.g. Bell et al. (1981) or Gandikota et al. (2004), vacuum was applied simultaneously to heating to set the dough structure. In conventional baking, dough inflation is driven by the increase in temperature which favours the release of gases into gas cells of dough and the adiabatic expansion of gas. As deformable to a large extent, the dough expands without a high increase in pressure within gas cells (2 kPa at most). Under partial vacuum baking, the decrease in external pressure and temperature are combined. In the present study, Magnetic Resonance Imaging (MRI) scanning of dough baking under vacuum conditions made it possible to separate the contribution of the temperature increase and partial vacuum to the overall inflation during baking. With moderate vacuum, rolls were found to be 20% more expanded than those baked using a conventional convection oven. Examination of MRI scans acquired just after vacuum application also concluded to uniform repartition of gas fraction through the dough section. As early crust setting interferes with the crumb setting e.g. Wagner et al. (2008), heat flux should be limited at the beginning of baking in order to delay the drying process as well as the setting of the periphery; ideally crust setting should occur after bubble inflation at the dough core had occurred. Provided that low drying rates were managed, partial vacuum baking could possibly favor bubble inflation throughout the crumb well before the setting of the peripheral layers. This was illustrated in the present study by varying the oven temperatures