Paprika contains high amounts of the functional flavonoid luteolin. However, the naturally occurring compounds luteolin-7-O-(2-apiosyl-6-malonyl)-glucoside (L-7-AMG) and luteolin-7-O-(2-apiosyl-glucoside) (L-7-AG) have low absorption rates in the body. We investigated whether the heat supplied during cooking would result in the conversion of L-7-AMG and L-7-AG to the more absorbable luteolin-7-O-glucoside (L-7-G). L-7-G was stable at pH 3 and 5 and was not hydrolyzed, while L-7-AG was hydrolyzed to L-7-G at pH 3 and maintained total luteolin. L-7-AMG underwent continuous hydrolysis to yield L-7-AG and L-7-G at pH 3 and above 100°C. At pH 7, the total luteolin content decreased in all glycosides. These results indicate that a temperature of 100°C or higher and acidic conditions (pH 3) are desirable for obtaining low molecular weight luteolin glycosides.

We aim to study the effects of various manufacturing process parameters on nutritional components (proximate components, fatty acid,and mineral content) and antioxidant activity (DPPH radical-scavenging activity) in retort products. This study followed an orthogonal experimental design, and analysis of variance was used for data analysis. We analyzed retort products based on five manufacturing process parameters, namely, raw materials, package conditions, seasoning solution, heating temperature, and heating time. The results revealed that raw materials, seasoning solution, and heating time of retort products have the greatest impact on the nutritional component content and antioxidant activity of the edible part of the products during the manufacturing process.

Easily understandable sensory evaluation terms for curry sauce were developed for experts. We collected 114 terms from seven retort curry products, narrowed them to 34 terms through discussions, and then developed them as "The sensory evaluation terms for curry". Using these evaluation terms, an analytical sensory evaluation was conducted on a panel of experts, confirming that the sensory evaluation terms appropriately described the characteristics of each retort curry sample. Subsequently, we conducted a sensory evaluation on a panel of non-experts using a method incorporating the CATA (Check-All-That-Apply) method. The results showed that the non-expert panel was able to describe the flavor characteristics of each sample using the evaluation terms, and the correlation coefficient (r) between the results of the non-expert and expert panels were >0.6 for 29 of the 34 terms. This suggests that "The sensory evaluation terms for curry" is useful for both experts as well as non-experts, such as general consumers.

In this study, we aimed to examine the effect of cooking temperature, cooking duration and storage duration on the texture of soft-boiled eggs (Onsen eggs). Fresh eggs and eggs stored at 25°C for one or two weeks were heated at 65°C, 68°C, and 70°C, and the yolks and whites of the eggs were analyzed. The storage durations significantly decreased the firmness of egg whites in eggs cooked at 68°C and 70°C, but did not have an effect on egg whites cooked at 65°C. The hardness of egg yolks heated at 65°C, 68°C, then 70°C decreased according to storage duration Additionally, increased cooking times affected the hardness of Onsen egg yolks. Firmness of egg whites was also affected by cooking duration in eggs cooked at 70°C. These results indicate that small differences in cooking temperature can influence the coagulation state of Onsen eggs.

This study aimed to elucidate the effects of adding water during the cooking of "Bikkuridaki" based on the cooking properties and the quality of cooked brown rice. In the Bikkuridaki method, soaking before heating did not affect rice's moisture content and hardness, indicating that extensive soaking before heating can be omitted in this cooking method. The addition of water at 0°C rapidly lowered the temperature of the cooking liquid, promoted the rupture of the pericarp and seed coat, and increased the area of exposed endosperm immediately after reboiling compared to that at 20°C and 98°C. Consequently, water absorption into the endosperm and starch gelatinization was promoted. The solid content leached into the cooking liquid increased, as did the cooked brown rice's softness, stickiness, and whiteness. It was also observed that the measurement of the area of the exposed endosperm utilized in this study could be used to determine the properties of cooked brown rice.

We evaluated the quality characteristics and palatability of sponge cake made using a microwave compared with a conventional oven. We compared three samples, each containing a proportion of wheat flour and sugar fixed at 30%, a conventional oven-baked sponge cake containing 40% egg (OS), microwave-cooked with the same ratio (MS), and microwave-cooked cake containing 20, 12.5, and 7.5% egg, water, and oil (MB), respectively. The microwave shortened the heating time to 1/15 compared with the oven. The specific volume of MS was higher than that of OS, but the structure of MS was non-uniform. MS was not preferred because of its hardness and mouth feel. Although MB had a marginally lower specific volume than OS and MS, it had a soft and brittle structure and was preferred over MS. In the case of microwave heating, the palatability was improved by using the MB ratio as opposed to the MS ratio. Furthermore, in sensory evaluation, MB was evaluated favorably in that it had a unique softness and was of different quality and palatability from OS.