The textural properties of food taking different forms, classified on the basis of the eating functions of the elderly, were measured at the Nursing Home S in Kanagawa Prefecture for the elderly. The results demonstrated that the forms of food that require little mastication efforts, and have a texture most easily lumped together within the oral cavity, were food that were soft and high in cohesiveness. These results indicate the importance of measuring the textural parameters of the food served at hospitals and nursing homes for the elderly, for identifying whether or not an individual with deteriorated eating function will be able to take in food in a safe way.   In the case of beverages such as water that are smooth-flowing, the front-end speed of the bolus at the pharynx is high, which means that people with impaired swallowing functions have a high risk of aspiration. To safeguard people with swallowing difficulties, efforts are being made on improving the textural aspects of food, such as adding thickness to liquid food when they are served. Accordingly, the physical properties of semi-liquid foods thickened with the commercial thickening agents, containing xanthan gum, guar gum and processed starch as main ingredients, as well as their relations with muscle activities during swallowing were investigated. The outcome of the study revealed that, in samples ranging from yoghurt-like hardness to tomato ketchup-like hardness, differences exist in the relation between the physical properties of samples and muscle activities, between xanthan gum or starch samples, whose solid-like structures results in long relaxation time, and guar-gum type samples, whose liquid-like structures in short relaxation time. The outcome of this study suggests that safer swallowing can be secured through good understanding of the thickening ingredient contained in the commercial thickening agents.