Impact of selected process parameters on crust flaking of frozen partly baked bread

Partially baked bread or partly baked bread can be frozen to extend its shelf life. Freezing can also be responsible for damage such as crust flaking. This paper presents a study aimed at identifying the process parameters that can interact with crust flaking.The study used a French baguette as a model system. The effect of proving condition (50% and 90% air humidity at 27°C), chilling condition after partial baking (50-55% and 90-95% air humidity at 20°C) and freezing condition (blast air freezer with the centre bread temperature at the entrance in the freezer of 35°C, 45°C or 55°C) on part baked bread was studied. The chilling condition after partial baking appears to be the most influent parameter on crust flaking followed by proving condition that also had a significant but not so strong impact on crust flaking. Generally, higher air humidity during the process tends to minimize crust flaking. The size of the piece of crust flakes seems to increase with increasing crust flaking. A higher temperature of the partially baked bread at the entrance of the freezer (55°C vs. 35°C in our conditions) seems to enhance the crust flaking phenomenon; nevertheless, this trend was not always significant in all our tests. These results have been used to define to process conditions that can provoke or minimize crust flaking of French baguette.