We investigated the effects of the physical properties of food boluses on tongue activity just before swallowing during food mastication in humans. Electromyographic (EMG) activity was recorded from the skin over the mylohyoid muscle (MH) of eight adult subjects during mastication of three kinds of food (gumi candy: G, peanuts: P, rice cake: RC). The texture of food boluses collected from the oral cavity just before swallowing was measured using a creep meter according to a texture profile analysis. The amplitude of the MH-EMG just before swallowing was significantly (p<0.001) Larger during mastication of RC than of G and P. Adhesiveness was significantly (p<0.001) higher in the RC boluses than in the G and P boluses. These results suggest that highly adhesive triturated food requires forceful movements of the tongue to form a bolus just before swallowing.