We combined a food emulsifier (oil setting agent) with a liquid oil to prepare solid fat and examined how the addition of solid fat to mashed potatoes affected their physical properties and stability. Addition of ≥ 4% of the oil setting agent to liquid oil yielded a stable solid fat, and this solid fat had weak properties for large shear. However, gelation was promoted with the standing time. When the resulting fat was added to mashed potatoes, there was little oil separation. Moreover, allowing the mashed potatoes to stand enabled fat stabilization. The thickness, ease of cohesion, and ease of swallowing with mashed potatoes supplemented with the fat made from the oil setting agent did not significantly differ from those of the highly regarded mashed potatoes supplemented with oil. The above results indicate that adding solid fat prepared with an oil setting agent to mashed potatoes is an effective way of making them stable and easy to eat.

In this study, the use of tapioca starch in the production of custard cream was tested. We used two starch types: distarch phosphate (P) and acetylated distarch phosphate (AP). We also used starches performed an enzyme (E) treatment on them (P+E, AP+E) resulting in 4 starch types in total. The kuchidoke (‘melt in the mouth' texture), which is important in the favourability of custard cream, was quantified and examined. P+E custard cream showed good kuchidoke, shape retention, and favourability when used as a substitute of 10 % of wheat flour. Moreover, custard cream containing P+E had a high yield stress, excelled at shape retention, and its thixotropic parameters and consistency index values were low. Continuous compression measurements showed that P+E had high kuchidoke, as it showed similar results to wheat flour custard cream, which was already considered to have high kuchidoke. Thixotropic parameters and consistency index values obtained through a viscometer showed a high correlation with smoothness, lightness, and kuchidoke results obtained from the sensory evaluations. These results indicate that these methods are an effective way of measuring the physical properties and quantifying levels of kuchidoke.

The purpose of this study was to investigate and compare the chemical components of the unused shellfish, ibokisago (Umbonium moniliferum) with other shellfish and to examine its potential as a food resource. The water content of the raw soft tissue was 77.5% less than other shellfish and contained about twice as much crude protein as oyster and short-neck clam. Extractive components of raw meat were rich in taurine, arginine, and AMP, although levels of glutamic acid and glycine were poor compared with other shellfish.

The levels of the extractive compounds were retained in the packaged meat cooked in boiling water. Upon sensory evaluation, the fishy odor was determined to be weak, and sweetness was found to be stronger in the ibokisago soup cooked for 10 minutes than the one cooked for 60 minutes. In addition, it was revealed that the umami and sweetness of the ibokisago soup mixed with dried bonito or boiled-dried sardine were stronger than that of the soup prepared from individual ingredients.

Upon examining the degree of protein degradation in minced meat fermented with amazake at low temperature(5°C), the protein decomposition was found to be gentle. In order to clarify the effect of meat fermentation using amazake such as softening the meat faster, the preservation condition (refrigeration, freezing) of rice-koji and the salinity concentration of amazake was examined. The protease activity of rice-koji tended to increase with the preservation period for both refrigerated and frozen samples, and the frozen preserved rice-koji did not show significant deterioration. Upon adding sodium chloride to amazake, its protease activity increased at the enzyme reaction temperature of 55°C. Since it is considered that fermenting with amazake containing salt has higher versatility in cooking, it is necessary to clarify the effectiveness of adding salt at 5°C, which is currently the actual condition for meat fermentation.

Surveys were conducted to investigate the culinary habits and practices among college and vocational school students, who started school between 2007 and 2012 and graduated between 2009 and 2016. A total of 1,361 students were surveyed once during their first month at school, then a second time one to two months before graduation. The survey results showed an increase in both interest and opportunities to cook, as well as an increase in the number of the students having a specialty dish over the course of their enrollment (between freshman year and graduation).

The respondents were categorized by gender, living arrangement, cooking frequency and cooking attitude and interest. The results showed that those with increased opportunities to cook while in school had a higher number of dishes they could cook; and in fact, a higher number of students had a specialty dish. Moreover, it was found that it was essential for students to take an interest in cooking in order to have their specialty dish.

Therefore, it is important for students to get more opportunities to cook, to increase the cooking frequency, and to have interest in cooking in order for them to prepare their meal as adults that go out into the world.

This study was conducted for analysing the effects of temperature and holding time (at the same temperature) on the coagulation of eggs while preparing soft-boiled eggs having preferable tastes.

The obtained results are outlined below:

— Upon setting whole eggs in thermostat water at 65°C, 68°C, and 70°C, the corresponding time periods required for the temperature of eggs' centres to reach the water temperature are found to be 27 min, 28 min, and 30 min, respectively. Furthermore, the egg whites retain their fluidity at other temperatures, whereas the heights of egg yolks vary according to the associated water temperature.

— At 65°C, the egg white is found to be in liquid state, and its fluidity is retained even after 210 min, though decreased as the holding time. However, the egg white at 68°C has reduced fluidity owing to the longer holding time. At 70°C and after 30 min, fluidity of the egg white is not observed.

— The heights of egg yolks at 65°C and 68°C tend to increase upon increasing the holding time. However, no significant difference is observed at 70°C.

Hence, it can be concluded that the coagulation states of the egg white and egg yolk are affected by the associated temperature and holding time, respectively. Based on these results, indicators can be developed for preparing preferable soft-boiled eggs.