Kaoru Sakamoto

[Purpose] Despite the fact that granulated sugar is a sucrose crystal and its purity is high, there are different types of granulated sugar with different heating and melting characteristics. The heating and melting properties of granulated sugar also vary depending on the milling process. We have prepared caramel sauces and candies using granulated sugar, pomace sugar, and their milled products with different heating and melting properties, and found that differences in taste and color were observed. The melting characteristics of sugar may also affect cookies and other baked goods. Therefore, we prepared cookies in which powdered sugar is often used and conducted experiments to determine how powdered sugar affects the quality of the cookies. [Methods] Powdered sugar WP (average particle size 40 μm) was prepared by ball milling using commercial granulated sugar W (particle size 0.50 ± 0.06 mm). The melting characteristics of each sugar were observed by differential scanning calorimetry (DSC, Thermo plus EVO2, Rigaku Co., Ltd.). Cookies were prepared using these sugars, and observed by polarized light microscopy, scanning electron microscopy, color difference measurement, rupture strength measurement, and sensory evaluation. [Results] The endothermic curves of DSC were different between W and WP sugars, and the heating and melting properties were different. The sensory evaluation results showed that W cookies and WP cookies differed significantly in color, appearance, bitterness, and hardness, and were perceptibly different in the color difference measurement. These differences were different from the experimental results obtained by preparing candies by baking granulated sugar alone. Microscopic observation showed that granulated sugar remained in the cookie dough before baking. After baking, the melted granulated sugar was observed to harden in such a way that it enveloped the grain structure of the flour starch. From these observations, it was inferred that in the cookies, the remaining melted sugar dissolved in a small amount of water before reaching the melting point of sugar as the temperature increased.

This study obtains data to develop methods for advertising the rock oyster (Crassostrea nippona) as a regional branded food by investigating the degree of recognition of the characteristics of the rock oyster, the Pacific oyster (C. gigas), and the common oyster by young people living in oyster-producing regions. The survey was conducted in the production regions of Japan, namely, Nagasaki, Hyogo, Miyagi, and Hiroshima prefectures. The participants were university students who would become future consumers of the rock oyster. Approximately 40% of the participants recognized the rock oyster; furthermore, less than 20% of them had consumed it. Thus, most participants did not recognize and/or had never consumed the rock oyster. Furthermore, the season of the rock oyster was identified to a lesser degree than that of the Pacific oyster. Most participants could not identify the production region of the rock oyster. The most common perceptions of nutrients and dishes associated with oysters were minerals and fried and grilled dishes, respectively. These findings are useful as a basis for developing methods to advertise the rock oyster as a regional branded food.

<p>We investigated the influence of soaking temperature on the water absorption in three cultivars of Japonica rice, Kinuhikari, Sasanishiki, and Hatsushimo, based on the modified water absorption rate calculation method for rice. The grains of each cultivar were processed under different conditions, i.e., 70% polished and polished rice. We compared the water absorption curves of grains soaked in water at 5°C, 20°C, and 40°C for 10 min to 24 h to ensure that the absorption had reached equilibrium. The absorption curves of grains soaked at 5°C and 20°C intersected those of grains soaked at 40°C in all cultivars of both 70% polished rice and polished rice. This "reverse phenomenon" was specific to the granular shape of the rice grain. The findings for these three cultivars descended from the different rice lines contradict the established theories in the field of cookery science. It is suggested that this occurs for many cultivars of Japonica rice.</p>

This work addresses how granulated sugars with different melting points from two different refineries affect the taste of cooked food. Candied sweets and caramel sauces were prepared using the two types of granulated sugars. According to sensory evaluation, the candies and caramel sauces prepared by heating the wet sugar crystals, which remained undissolved in the solution, showed different tastes. This was confirmed by the color difference analysis and HPLC analysis of these two caramel sauces. However, the caramel sauces prepared from aqueous solutions of the sugars were not significantly different from each other in flavor. These results suggest that granulated sugars with different heating characteristics may have different crystal structures. During cooking, in which the sugar crystals are heated without being completely dissolved, the heating and melting characteristics of the sugars should be taken into consideration.

We measured the water absorption of rice grains when it is soaked in warm and cold water, as well as the amount of rice contents suspended in the soaking water. Rice grains were soaked in water with temperatures ranging from 5&deg;C to 50&deg;C, for 5 to 240 minutes. The water absorption curves obtained, crossed each other. At the equilibrium state, rice soaked in cold water showed higher water absorption than rice soaked in warm water. Measurement of suspended rice contents in soaking water showed that warm water adjusted to 40&deg;C and 50&deg;C had the highest rice contents. Subsequently we measured the adjusted water absorption by including the values for rice contents that was suspended in soaking water. The adjusted water absorption curves obtained also crossed each other. Once again, it was observed that at the equilibrium state, rice grains soaked in cold water showed higher water absorption than that soaked in warm water.