Qualité des pommes de terre : nouvelles méthodes d'évaluation calibrées sur l'analyse sensorielle

Quality of potatoes : new assessment methods calibrated by means of sensory analysis [frying index]. For the potato sector, raw material quality became an important criterium because it determines the type of use and the transformation ability of the tubers. It is now primordial to be able to identify the quality level of a share by reliable and objective methods. The qualitative criteria of potatoes are for the most estimated via sensory tests. During this survey, we measured several texture descriptors (desintegration, flouriness, granulation), the flesh colour, the after-cooking blackening susceptibility, the taste intensity and the after-frying coloration of the samples. In order to get rid of the human subjectivity, we studied the potentialities of near infrared spectrometry (NIRS) and of image analysis to predict or to measure these sensory behaviours. We observed high correlation between real values and values predicted by NIRS models, mainly for texture descriptors and flesh colour. Frying index prediction by NIRS is acceptable, but less precise than its measurement by image analysis.