Résumé
Granules from different starch sources vary in composition, size and shape. The size distribution of starch grains and their shape contribute to some functional properties (e.g. viscosity, water retention capacity, starch gelatinization) but also certain mechanical properties. Conventional physicochemical measurements of starch properties are often costly and difficult to access. The work presented here aims to contribute to the evaluation of the quality of yam tubers through the development of an automated method for measuring the size and shape of starch grains in RTB products. This protocol is based on the detection of starch grains by iodine staining of starch from RTB flour. Once stained, a drop of the solution is observed under the microscope and an image is taken. A morphological segmentation based on the watershed algorithm is then applied to images in order to detect every starch grain. Finally, the grain starch size and shape are calculated based on appropriate scale and indicators.