Impact of long-term frozen storage on the dynamics of water and ice in wheat bread

Frozen storage of bread has a substantial impact on the dynamics of water and ice in the crumb and crust. In this study, the impact was characterized using wheat bread stored at −18 °C for a long term of ∼4 months. The frozen bread incurred a considerable loss of the crumb water that migrated out and formed ice crystals on the bread surface. Such a moisture decrease underwent more rapidly for the bread stored without intact crust, suggesting the specific role of crust during frozen storage. Moisture also redistributed significantly within the frozen crumb, resulting in an elevated crumb heterogeneity of freezable water. This redistribution of freezable water was accompanied by a progressive recrystallization of the crumb-borne ice crystals, which were measured to grow into bulk sizes using a modified calorimetric procedure for analyzing the crumb samples at their as-frozen states.

► We studied the dynamics of water and ice crystals in wheat bread stored at −18 °C for ∼4 months.
► Frozen bread considerably lost the crumb water that migrated out and formed ice crystals on the bread surface.
► In-crumb redistribution of water resulted in an elevated crumb heterogeneity of freezable water.
► Evolution of as-frozen ice profiles was probed over frozen storage using a modified calorimetric procedure.