We investigated the effects of temperature on the physical properties and swallowing characteristics of mashed potato samples with added oil and fats. The firmness of all samples was evaluated soft as the temperature increased, and a similar tendency was observed for the hardness of textural properties. The thickness was evaluated significantly little as the temperature increased in the mashed potato sample with added oil (PO), but no significant difference was observed in the samples with added solid fats (PF and PS) at any temperature. In the PO sample, the thickness was related viscosity of the oil, whereas in the samples with added fats, the presence of a solid fat portion was suggested. Easy of swallowing was found to significantly easy as the temperature increased in the PO sample. The PF sample presented significantly easy at 50°C relative to 20°C, but significant differences were not observed at any temperature in the PS sample. In PO sample, easy of swallowing was influenced by the viscosity of the oil, and in the PF and PS samples, easy of swallowing was likely related to the temperature-dependent melting behavior of solid fats, which at body temperature exhibit the apparent dynamic viscosity η′app.
