Abstract
The effects of the properties of oil and fats on the ease of swallowing mashed potato were examined to compare samples with added oil or fat with those with water (control) added in the same proportions. The comparison was made by measuring the physical properties and conducting a sensory evaluation. The samples of the mashed potato were prepared by adding water as the control, and liquid oil O, solid fat F (fat-like gel) and solid fat S (shortening) to give three different physical properties of fats and oil. The hardness and yield stress of the mashed potato were greatly influenced by the physical properties of the solid fats. The average resistance force obtained by measuring the resistance in the horizontal direction gave an indication of the ease of sliding and smoothness of the sample to show the validity of this method.
Microscopic observation of the mashed potato showed that the dispersion was different among water, oil and fats, and influenced the physical properties. A sensory evaluation showed the sample with added water to be significantly harder than the samples with added oil and fats, and tended to be less smooth. The samples with added water and oil were evaluated to be significantly lower in their thickness and sense of remaining in the mouth, and higher in their ease of swallowing than the samples with added solid fat F.
