To develop a dry green soybean product that can be stored and distributed at room temperature and easily eaten, we investigated a method for puffing and drying green soybeans using a food dehydrator and a microwave oven. Frozen green soybeans were thawed in running water, immersed in a 3 % (w/w) saline solution, and pre-dried using a food dehydrator. Green soybeans with a moisture content of 20 % at the end of pre-drying were heated and puffed using three microwave conditions: 10 W/g for 40 seconds, 50 W/g for 25-40 seconds, and 10 W/g for 90 seconds. The samples were subsequently finished drying in a food dehydrator. This microwave method produced a palatable dry product; therefore, it was applied to five green soybean varieties differing in grain size, color, and varietal characteristics. The swelling ratios ranged from 136 % to 189 %. All varieties had moisture content and water activity that allowed them to be stored and distributed at room temperature, and produced puffed dry products that retained the characteristics of each variety.

The advent of next-generation synchrotron radiation facilities, such as NanoTerasu, has enabled the visualization of food microstructures at unprecedented spatial resolution. For frozen food products, preserving the delicate three-dimensional network of ice crystals and the surrounding matrix during scanning is critical. However, most high-resolution beamlines are primarily designed for room-temperature operation, lacking the specialized infrastructure required for cryogenic imaging. Without modifying the existing room-temperature sample stages, we developed a portable, cost-effective cooling jig based on a "top-down" natural convection mechanism. By positioning a dry-ice reservoir above the sample within a sealed capsule, we induced a downward flow of cold, dense air that surrounds the entire specimen. This approach ensures a uniform cryogenic environment and eliminates the thermal gradient inherent in conduction-based cooling. This study describes the design of the device and its effectiveness in enabling high-resolution in situ X-ray CT imaging of frozen samples at a standard room-temperature beamline.

We evaluated the effects of different cooking methods on the levels of γ-glutamyl-S-allylcysteine (GSAC), S-allylcysteine (SAC), alliin, and γ-aminobutyric acid (GABA) in intact garlic cloves using HPLC. GSAC decreased under all cooking methods tested (baking in foil, boiling, steaming, microwaving, and frying), with the greatest reduction observed during baking. SAC remained unchanged during baking but decreased under the other cooking methods. Alliin remained unchanged during steaming and microwaving but decreased under the other methods. Conversely, GABA increased significantly after baking, and also during boiling and steaming. These results suggest that cooking methods differentially affect the retention of functional components in garlic, although the role of temperature profiles remains to be clarified.

The contents of three off-flavor aldehydes (2-methyl butanal, 3-methyl butanal, and 3-(methylthio)propanal) were investigated as key aroma compounds associated with raw soy sauce deterioration. Results using gas chromatography (GC) and GC-mass spectrometry (GC-MS) showed that the contents of the three aldehydes, which were low in fresh raw soy sauce, increased with aging at 30 ℃, adversely affecting the soy sauce aroma. Furthermore, their generation involved the Strecker reaction, with amino acids as precursors. The concentrations of isoleucine, leucine, and methionine in the raw soy sauce positively affected the generation of each aldehyde. In particular, the generation of 3-(methylthio)propanal, produced from methionine as a precursor, was a particularly potent compound during aging. On the other hand, it was found that raw soy sauce made from Kyushu No. 174 (rich in β-conglycinin, one of the major seed storage proteins of soybean with low methionine content) showed a low methionine concentration and suppressed the generation of 3-(methylthio)propanal during deterioration compared to those made from other soybeans.

The household refrigerator serves as a common storage environment for foods and is an indispensable household appliance, with almost 100 % of ordinary households having one. Various gaseous chemical substances are known to be emitted from foods through several mechanisms, including time-dependent chemical changes in food components, microbial metabolism, and the direct release of volatile constituents. Therefore, a wide variety of food-derived gaseous chemical substances are considered to be present in household refrigerators. However, only a limited number of studies have qualitatively or quantitatively measured specific gaseous chemical substances inside household refrigerators. These substances may affect food quality by, for example, causing odor transfer and influencing fruit and vegetable ripening. In addition, leakage of such substances into the surrounding space may contribute to indoor odors and potentially affect human health. This review summarizes the current status of studies on the measurement and monitoring of gaseous chemical substances in household refrigerators and discusses their possible effects on stored foods, the surrounding living environment, and human health.

We have compared the content of major taste-active components (ATP-related compounds and free amino acid content in leg meat), previously identified in snow crab (Chionoecetes opilio), in red snow crab (Chionoecetes japonicus) before and after ice-cold storage. The samples used for this study were red snow crab landed at Shinminato Fishing Port, Toyama Prefecture, in spring (May). We also examined the effect of freshness on the aforementioned taste-active components after boiling of the crabs. The results showed that the crabs with reduced freshness had significantly lower levels of components contributing to sweetness and umami than fresh crabs. Furthermore, when the crabs with reduced freshness were boiled, they contained significantly lower levels of taste-active components, such as glycine and arginine, than fresh crabs. Therefore, a reduction in red snow crab freshness could negatively affect its flavor after boiling.

This study analyzed fruits from five greenhouse-grown paprika cultivars harvested at different times in 2014 and 2015. The results showed that the γ-aminobutyric acid (GABA) and luteolin contents, as well as the antioxidant capacity varied as a function of both cultivar and harvest time. Across all cultivars analyzed, the luteolin content tended to be higher in fruits harvested between October and December.

We investigated the appearance of and change in luminescent components during the moromi production process by measuring excitation-emission matrices (EEM) at a sake brewery in Miyagi Prefecture. Six fluorescent components (A to F) were measured in EEM, and the EEM spectra were analyzed using principal component analysis (PCA) and multidimensional scaling (MDS). It was confirmed that the principal components could be separated based on the number of days elapsed during the moromi fermentation process. Multiple regression analysis was performed on the physical properties of sake in the MDS-derived two-dimensional space, and it was found that the acidity and gravity of sake correlated with the XI axis.

This study investigated the emulsifying abilities of green tea (GT) and black tea (BT) infusions to elucidate why they are often used as “palate cleansers” to reduce oral fat sensation. Tea samples were prepared by immersing tea bags in hot water. Both GT and BT samples showed lower interfacial tension against soybean oil than water. Related to the low interfacial tension, they emulsified higher amounts of oil compared with water after mixing with oil in the absence of lecithin. However, in the presence of lecithin, GT, but not BT, significantly enhanced the lecithin-induced emulsification. Stereomicroscopic observations showed that a large number of fine oil droplets were dispersed in GT, whereas coarsened oil droplets and brown aggregates were observed in BT. Enzymatically de-galloylated GT (GTt) maintained the ability of GT to enhance the lecithin-induced emulsification. This ability was found to be independent of pectin, caffeine, catechins, and gallic acid. However, it was lost by removal of polyphenols using polyvinylpolypyrrolidone. These results suggest that not only the emulsifying abilities of GT and BT themselves but also unknown non-galloyl polyphenols in GT capable of enhancing lecithin-induced emulsification in foods contribute to the reduction of oral fat sensation.

Contamination of milk with minute amounts of hexanal results in oxidized flavor. We have developed a trace-level procedure for aliphatic aldehydes, including hexanal, using 1,3-cyclohexandione as a fluorescent labeling agent in HPLC. However, measurement of trace amounts of hexanal with the reported method of acetic acid, 1,3-cyclohexanedione and ammonium acetate resulted in a higher quantitative value than expected. Upon investigation, we found an inseparable byproduct having the same retention time as fluorescently labelled hexanal. To solve this issue, the amount of byproduct was reduced significantly by replacing the acetic acid with formic, citric, or sulfuric acid. To confirm the precision of the modified analytical procedure, we validated the labelling method using sulfuric acid for milk, yogurt, and milk coffee. We accurately quantified several aldehydes, including hexanal, generated from milk irradiated with 2000 lux LED light with the improved analytical procedure.

In barley used to produce roasted barley tea, higher protein content is considered desirable. The aim of this study was to examine how variations in the protein content of raw barley grains affect the volatile flavor compounds in roasted barley tea. The six-rowed barley cultivars “Kashima-mugi” and “Kashima Goal” were cultivated under four different fertilization conditions in three replicates over two crop years, to obtain barley grains with a range of protein contents. These grains were roasted and extracted with boiling water, and the volatile compounds in the resulting barley tea were analyzed by gas chromatography mass spectrometry to estimate the concentrations of 21 volatile compounds. In the barley tea, the concentrations of pyrazines, thiazoles, and furfuryl pyrrole showed significant positive correlations with the protein content, while the concentration of furfural showed a significant negative correlation with protein content. Conversely, the concentrations of 2-methylbutanal, 3-methylbutanal, hexanal, 4-ethyl-2-methoxyphenol, and 2-methoxy-4-vinylphenol were not affected by the protein content of the raw grains. These results suggest that the protein content of raw barley grains influences the quantity and composition of volatile compounds formed by the Maillard reaction and subsequent reactions in the barley tea, and that higher protein content leads to a stronger roasted flavor from pyrazines and weaker sweet flavor from furfural.