This paper describes a texture sensing system for gel food. Considering the elastic deformation of human tongue, we propose a method to evaluate the food texture by using a simple artificial mastication model with an imitation tongue. After explain a basic principle of variable elasticity of the developed imitation tongue, we show that it can reproduce the elasticity of human tongue from the relaxed to contracted conditions. In addition, we show how the pressure distribution during the artificial mastication of gel differs with respect to the elasticity of imitation tongue. Based on the numerical model between the pressure distribution data and the value of sensory evaluation, we evaluate the food texture. Through the experiment of food texture estimation, we reveal that there exists the appropriate elasticity of imitation tongue, for texture terms and characteristics of gel food.