This article deals with a functional approach based on the projection upon a beta-spline basis in order to analyze Time Intensity curves. The modelization is followed, on the one hand, by the assessment of the repeatability and the discrimination ability of the panelists, and on the other hand, by the determination of a good compromise over repetitions. Finally, a multidimensional analysis enables the comparison of the shapes of the curves associated with the assessors (assessors' signature) and the characterization of the products. The properties of this functional approach are illustrated with TI curves describing sweetness variations of drinks.