Grading of flour based on colour information

The quality of flour is mainly determined on the basis of its color and protein content. Flour color grading is performed off-line from the milling process, in a laboratory. Thus there is a need for an instrument to measure flour color on-line and give an alarm if the result is outside the specified acceptable range. Based on the analysis of the color properties of flour and optical measurement methods used in experiments, two measurement approaches are proposed, the 'all spectrum method' and the 'abridged spectrum method.' Taking into account the costs of the sensor to be used under real quality testing conditions, the method based on the abridged spectrum is regarded as more appropriate. This paper describes a design for a four-channel color measuring system with an optical fiber sensor head. The sensor has been employed for the practical implementation of the method under laboratory conditions, giving satisfactory results.