Influence of Baking Conditions on Bread Characteristics and Acrylamide Concentration

Author(s): Tzvetelin Dessev, Valérie Lalanne, Javad Keramat, Vanessa Jury, Carole Prost, Alain Le-Bail

The effect of baking temperature (vault and hearth) and steam injection on bread characteristics and acrylamide content was investigated using a central composite design. Breads were baked in a stone oven (1 m² internal baking surface). Response variables measured were specific volume, crumb porosity, crust to crumb ratio, crumb hardness, median gas cell size, crust coloration and acrylamide concentration. The specific volume, crumb porosity, crumb hardness and median gas cell diameter were mainly affected by the stone temperature and steam injection level. Highest specific volume (5 mL.g-1) and crumb porosity (86%) were obtained at highest stone temperature (230°C) and steam level (300 mL). At the same baking conditions and highest vault temperature (230°C), a minimal crumb hardness and median gas cell diameter were attained, as well. A negative linear correlation between the specific volume (crumb porosity) of the bread and its textural properties (crumb hardness and median gas cell diameter) was found. Vault temperature mainly influenced crust characteristics. Thus, increased vault temperature increased the crust coloration and crust crumb ratio. Vault temperature and steaming were found to have greatest effect on acrylamide concentration. As they were increased the acrylamide concentration increased, too. Additionally, a strong correlation between crust color and acrylamide concentration was observed. As the crust total color difference increased up to 20-25, acrylamide concentration increased linearly. However, for a higher level of crust coloration the acrylamide concentration was found to leveling out or even to decrease slowly.