The objective of this study was to determine the effect of fat-based spreadable materials on the properties of a food bolus that subsequently forms in the oral cavity. Different amounts of butter, margarine, and fat spreads were mixed with artificial saliva and crushed bread crumbs to prepare a simulated food bolus and determine its texture. In addition, emulsions were prepared by mixing canola oil and water at different ratios and were evaluated in the same method. Results showed that the addition of a fat-based spreadable material reduced the hardness and adhesiveness of the simulated food bolus. This effect of spreadable materials on simulated bolus was enhanced with increasing amounts of the additive. The fat spread with a low fat content was more effective than butter and margarine in reducing hardness and adhesiveness. Regarding the results of the evaluation of the canola oil and water mixture, the addition of oil reduced the hardness, cohesiveness, and adhesiveness of the simulated food bolus compared to only water.

This study aims to clarify the characteristics and factors associated with regions where potatoes were established as part of hare shoku (special foods for festive occasions) in modern Japanese food. Examining trends from the end of the Taisho period through to the early Showa period, specifically around the 1930s, using "The Complete Collection of Daily Japanese Food" as a reference material, revealed that potatoes were mainly used in hare shoku as an ingredient for stews and soups in the cold and high-altitude regions of East Japan.

Detailed surveys were then conducted in the mountainous regions of Yamanashi and Gifu Prefectures, where hare shoku was prevalent, using reference materials such as diaries, travelogues, municipal magazines, and folklore research reports. In both regions, potatoes were had been introduced in the Edo period, cultivated continuously and actively, and incorporated into various hare occasions. In the process of being used for a long time, potatoes became established as part of the local food culture, were passed on as an important food and began being used for hare shoku.