Color measurement methods for optimization of oven operation (baking of sliced bread with superheated steam and hot air)

Abstract

An in-situ color measurement method during heating in an oven is required for optimizing the ovencooking operation. However, conventional colorimetric apparatus is not applicable because such processesusually involve high temperatures and wet surfaces. In this study, we equip an oven chamber with opticalfibers connected to a halogen light and spectrometer to perform the in-situ (real time) color measurement.To demonstrate the usability of this method, we observed the color change in white bread heated by hotair and superheated steam at 200C as a trial experiment, and compared results from two other types ofcolorimetric measurements of the samples after heating: a color image recording system using a digitalcamera, and a commercial spectrophotometer. We found that the value of L* decreased more quickly, andb* had a lower value for baking by superheated steam in comparison with baking by hot air at the sametemperature.