New method for determination of potato slice shrinkage during drying

Shrinkage during drying plays an important role in determining the quality of the dried product. In this paper, a method based on computer vision was used to analyze the effect of drying on shrinkage of potato slices. The computer vision system consisted of a digital camera, illumination, computer hardware and software was developed to capture and process the images. Variations in area, perimeter, major and minor diameters, diameters parallel and perpendicular to airflow, Feret diameter, roundness were measured in intervals during drying. All morphological features decreased smoothly with drying time. Shrinkage of the potato slices decreased almost linearly with moisture content. Results showed that airflow direction had significant effect on parallel and perpendicular diameters in 60 and 70 °C and had no significant effect when temperature was 80 °C. Drying time decreased with increasing air temperature.