Characteristic Coloring Curve for White Bread during Baking

Abstract

The effect of heating conditions on the crust color formation was investigated during the baking of white bread. The surface temperatures were monitored with thermocouples attached to the inside surface of the loaf pan cover. The trace of the surface color in the L^*a^*b^* color coordinate system is defined as the characteristic coloring curve. The overall baking process was classified into the following four stages based on the characteristic coloring curve: i) pre-heating (surface temperature < 110 °C), ii) Maillard reaction (110–150 °C), iii) caramelization (150–200 °C), and iv) over-baking (surface temperature>200 °C). A linear relationship was observed between the L^* decrease and the increase in weight loss of a sample at each oven air temperature. The L^* value appeared to be suitable as an indicator to control the surface color by baking conditions.