Effect of baking conditions and storage with crust on the moisture profile, local textural properties and staling kinetics of pan bread

- Baking conditions and presence of crust lead to changes in crumb texture during staling.
- The rigidity of bread crumb increases as the moisture level decreases, especially in the part undergoing a higher heating rate.
- Storage with crust leads to an increasing in firmness during storage.
- A first order kinetic model confirms that baking at high heating rate results in a faster staling.

To investigate the impact of baking conditions on staling kinetics and mechanical properties, pan breads were baked at 180 °C/34 min and 220 °C/28.6 min using a ventilated oven and metallic moulds. After baking, bread slices were stored with and without crust at 15 °C in hermetic boxes for 9 days. This investigation provides a textural and physical analysis by examining the Young's modulus, crumb density and crust/crumb ratio during storage. In order to understand the relationship between firmness and moisture content, a moisture profile and a Young's modulus profile were determined during the storage of bread. To fit the staling, a first order model was used. It was found that the kinetics were faster for samples baked with a fast heating rate than for those baked with a slow heating rate. Moreover, the staling rate of bread stored with crust was faster than for bread without crust and the outer crust area staled more rapidly than the centre of the bread slice. These results suggest that the firming of the crumb is related to moisture distribution between the crumb and crust and to the impact of local baking conditions on local firmness.