The use of digital imaging for evaluating color changes of rutab during drying in a cabinet drier

In this research using a digital camera, a PC and a graphical software; a simple and low cost method for the evaluation of colour of food materials is introduced. Analysis of digital pictures of the surface of samples can give L, a, b Hunter colour parameters and colour distribution. Drying of Kabkaab rutab in a range of temperatures (56, 66 76, 86 and 96 ˚C) and times using a cabinet drier was investigated. colour changes of the dried samples and the control were evaluated by analysing the digital pictures of the samples and showed that increase of temperature and time caused a systematic reduction of L, a, and b values. Taken into account colour changes of the samples and their drying rates at different temperatures, the drying temperature of 76 ˚C seemed to be the best condition for drying of Kabkaab rutab.