The concentration of flavonoids and the composition of volatile components in the juice of 16 shiikuwasha (Citrus depressa Hayata strains) and five other citrus fruits were investigated using high-performance liquid chromatography and headspace gas chromatography-mass spectrometry, respectively. The concentration of 13 flavonoids in these juices was determined. Nobiletin was detected in shiikuwasha juice (1.4-18.1 mg/100 mL). The main volatile components in shiikuwasha juice were limonene, γ-terpinene, p-cymene and linalool. Principal component analysis was performed with the concentration of flavonoids and the composition of volatile components. Scores for the 1st and 2nd principal components were plotted as a scatter diagram. Three groups were formed with shiikuwasha alone, but Ogimi kugani and Katsuyama kugani were located far apart. The citrus fruits of Okinawa prefecture were characterized by their volatile components and flavonoid constituents.

Using hydrocolloids as gelling agents, 15 kinds of hydrogels and 8 kinds of emulsion gels with different textures were prepared. To assess changes in pressure distribution, the gels were placed on a film-type multipoint pressure sensor and then crushed with the aluminum plunger. The gels were subjected to sensory evaluation of 4 kinds of texture attributes, “smoothness”, “elasticity”, “stickiness” and “granularity”, by 8 subjects. Then, the relationship between the values obtained by sensory evaluation and the pressure distribution data was numerically modeled by applying image texture analysis, and a suitable texture estimation modeling formula was derived. Using this modeling formula, 5 kinds of jellies and 3 kinds of puddings commercially available and of unknown texture were estimated. The modeling formula using the 15 hydrogels could estimate the texture of the 5 jellies with high accuracy (r > 0.8), whereas all 23 gels, including the 8 emulsion gels, were needed to estimate the texture of the 3 kinds of pudding with equivalent high accuracy.

Whey powder (WP) production efficiency is influenced by the deposition rate on the wall surface of the chamber during spray drying. However, the accuracy of computer simulation methods for this process is inadequate. In this study, in order to improve the accuracy when simulating WP deposition, we examine the effect of implementing a computational fluid dynamics (CFD) model to vary the drying rate depending on the drop water content and the deposition rate according to the glass transition temperature. Deposition and drying rate models were constructed using the experimental results of a single-drop drying test and differential scanning calorimetry. As water droplets evaporated more slowly during the drying process, the water content of the powder was increased. The simulation prediction that WP was deposited on the top and conical areas of the chamber was consistent with actual measurements. The accumulation of WP was higher than that of skim milk powder (SMP) because of the low glass transition temperature of WP particles. The simulation results for evaporation efficiency, evaporation capacity, evaporation mass flow rate, thermal efficiency, and exhaust temperature obtained using the improved CFD model were highly accurate and consistent with the measurement results. Such high-accuracy CFD simulations can be used to improve the optimization of processing conditions used in the milk powder industry.

Lutein is a carotenoid that is selectively taken up into the macula of the eye. Green leafy vegetables, such as spinach and kale, are known to be excellent sources of carotenoids. Although komatsuna (Brassica rapa var. perviridis) is a green leafy vegetable that is commonly consumed in Japan, little is known about its lutein content. Therefore, we investigated the lutein content of six komatsuna cultivars and the influence of hot air drying. The lutein content of the six komatsuna cultivars ranged from 3.7 to 5.4 mg/100 g FW, and it correlated with the SPAD values, which indicate chlorophyll content. Blanching of the komatsuna before hot air drying prevented the lutein content from decreasing. The lutein content of komatsuna powder that was produced in our laboratory ranged from 0.66 to 0.92 mg/g DW. When the komatsuna powder was stored at －30 °C, the lutein content remained stable for 6 months.

In this study, we determined how unfermented and fermented rooibos tea (RT and GRT) amounts, tea leaf weight, extraction time, and temperature influence 1, 1-Diphenyl-2-Picrylhydrazyl (DPPH) radical-scavenging activity, and total polyphenol and aspalathin contents. When RT and GRT were obtained through steeping 1.5, 2.5, 5, or 10 g of tea leaves in 500 mL of boiling water for 10 min, the total polyphenol and aspalathin contents and the DPPH radical scavenging activity increased with the increase in the amount of tea leaves used. When 10 g of tea leaves were extracted using 500 mL of boiling water for 10 min, the total polyphenol and aspalathin contents and the DPPH scavenging activity of GRT (about 940 µg/mL, and 5.9 mM ascorbic acid equivalent, respectively) were higher than those of RT (about 760 µg/mL, and 3.6 mM ascorbic acid equivalent, respectively). When 5 g of tea leaves were extracted using 500 mL of boiling water for 15-20 min, the total polyphenol and aspalathin contents and the DPPH scavenging activity of RT and GRT were higher than those extracted in 5-10 min. Notably, we observed almost no difference in the total polyphenol and aspalathin contents of RT and GRT when extracted at 80 °C compared to decocted for 10 min.