To determine quality characteristics, the physical characteristics of the flower stalks of 28 varieties and lines of choy sum and related species grown in greenhouses under low-to-moderate temperature conditions in Japan were investigated. Early varieties and lines sown on November 6 exhibited less flower stalk toughness, whereas those sown on February 6 showed greater flower stalk toughness caused by the low temperatures immediately after sowing, which suppressed flower stalk enlargement. Sensory traits of the early choy sum variety with moderate physical properties were also compared with those of other vegetables (Japanese mustard spinach and asparagus). The flower stalks of choy sum showed less bitterness and leafy smell than those of other vegetables, and the leaves were thin and flabby in texture compared to those of the other vegetables. Choy sum flower stalks and leaves eaten together were rated as slightly less sweet but more tender than those of the other vegetables.

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 This study aimed to clarify the effect of steam-heating temperature on the free sugar content in different chestnut varieties. The early chestnut cultivars tested were “Porotan,” “Tanzawa,” and “Sugihikari;” the medium varieties included “Ginyose,” “Rihei,” and “Tsukuba;” and the late variety “Mikuri.” Changes in the Brix and free sugar contents (sucrose, glucose, fructose, and maltose) of chestnuts were investigated at various steam-heating temperatures (raw, 50°C, 60°C, 70°C, 80°C, and 90°C). Results indicated that at higher heating temperatures, the content of sucrose, glucose, and fructose content decreased. Conversely, maltose content increased at lower heating temperatures. The reducing sugar contents of “Rihei” increased with heating. This study confirmed that chestnut varieties and heating temperatures significantly affect the sweetness of chestnuts.

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 In the summer of 2023, Japan recorded its highest ever average temperature on record including all comparable data. Aomori Prefecture recorded its highest temperature in August, which is the grain-filling period for rice. The daily mean temperature during the rice growing season in 2023 was higher than those in 2021 and 2022, especially in August. The percentages of whole grain for ‘Masshigura’ and ‘Tsugaruroman’ were significantly lower in 2023 than in 2021 and 2022, while the percentages of chalky grain in 2023 were significantly higher, at 38.2 and 36.8%. Abnormally high temperatures, such as those in the summer of 2023, were shown to negatively impact rice ripening, even in Aomori Prefecture. As global warming continues, even in Aomori Prefecture, known for its cool climate, it is necessary to develop mitigation techniques for ripening rice damage caused by high temperatures.

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 The effects of the plunger diameter and shape on the measured values were investigated to evaluate the firmness of strawberry fruit by penetration or compression tests. The measured values were greater for plungers with larger diameters than for those with smaller diameters, and for disk- or cylinder-shaped plungers than for spherical plungers. In addition, varietal differences in the firmness of fruit from eight strawberry varieties were detectable in six different plungers, although the varietal rankings tended to be inconsistent between the spherical and disc-shaped plungers. Furthermore, variations in the measured physical properties of strawberry fruits during storage were more detectable in plungers with larger diameters.

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 The purpose of this study was to investigate the volatile compounds in different types of katsuobushi and to clarify their relationship with the sensory characteristics, including the fresh aroma of katsuobushi. Five types of katsuobushi were collected, namely, Kame-bushi, Hon-bushi (three types), and Hadaka-bushi, and the aroma characteristics of their shavings were evaluated.
 To organize the sensory characteristics, the relationship between freshly shaved aroma, smoky aroma, meaty aroma, and oxidized odor was examined using Hon-bushi shavings stored under different humidity conditions. When stored at 32% humidity, the score for freshly shaved aroma decreased, showing a high correlation with smoky and meaty aromas and a negative correlation with oxidized odor. Conversely, at 83% humidity, the correlation between freshly shaved aroma and oxidized odor decreased, indicating that sensory characteristics changed with storage humidity.
 A comparison of the volatile compounds and sensory characteristics of the five types of katsuobushi revealed that Kame-bushi had a higher aldehyde and alcohol content, resulting in a stronger oxidized odor. In contrast, Hadaka-bushi had a significantly lower volatile compound content and a higher meaty aroma score but the lowest freshly shaved aroma score (4.21). This low score may be primarily be attributed to the weak smokiness derived from phenolic compounds.
 Volatile compounds vary depending on the type of katsuobushi, and phenols are believed to contribute to the perception of the freshly shaved aroma. Additionally, sensory characteristics are thought to vary based on the type of shavings and storage conditions, influenced by a decrease in smoky and meaty aromas and an increase in oxidized odor.

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 This study describes the design and evaluation of a workshop aimed to enhance consumer understanding and awareness of the occurrence of food by-products and the potential for upcycling in the food manufacturing industry. The results indicated that, prior to attending the workshop, few students prioritized factors, such as raw materials, production and processing methods, or environmental considerations when purchasing food. This finding implies that students generally displayed low levels of interest in the origins of the food they consume or in the maintenance of a sustainable diet. Through this workshop, many students gained an in-depth understanding of by-products and exhibited changes in awareness when making food choices. Additionally, the program was found beneficial for their learning, and the study observed indications of increased awareness of Sustainable Development Goals. To help consumers evaluate the value and taste of food from a broad perspective, we aim to further develop workshops that effectively support knowledge acquisition of and experience in the current state of food by-products and food waste, thereby promoting education for sustainable consumer practices.

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 This study tested the production of koji using lentils (Lens culinaris Medic.) as a raw material. The α-amylase activity of the lentil koji was higher, while protease activity was lower when skinless lentils were used compared to skinned lentils. The free amino acid content of the lentils increased by 2.48–5.30 times, and the total umami components, glutamic and aspartic acids by 1.17–4.78 times during the koji-making process. Amazake made with lentil koji had a yellowish tone compared to rice koji. The evaluation results of the texture, overall composition, and aroma were lower, but the taste was higher with skinless lentils. This study showed the possibility of producing unique koji with lentils as a raw material. Additionally, it also showed that the enzyme activity, umami components, and the characteristics of amazake produced with lentil koji could be changed by utilizing skinned and skinless lentils. These findings suggest that lentil koji can be used in various fermented foods.

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 The relationship between electrical properties and tissue structure of cut apples whose tissue state was changed by vacuum impregnation treatment was investigated. X-ray micro-CT observation showed that the porosity of the sample decreased as the pressure was set lower during the same time vacuum impregnation treatment using distilled water. In electrical impedance spectroscopy, the extracellular resistance was smaller, and the cell membrane capacitance (C_m) was larger at lower pressures. These changes correlated with the porosity change. In the vacuum impregnation treatment using sucrose solution, C_m decreased with increasing sucrose concentration. Therefore, it is suggested that the swelling pressure of the cell membrane changes with the osmotic pressure change of the impregnation solution, which affects the electrical properties.

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