The purpose of this study was to elucidate the gastrointestinal pharmacokinetics of betalains, violet betacyanins (betanin and its isomer) from red beetroot (Beta vulgaris L.var. rubra) and yellow betaxanthin (indicaxanthin) from cactus pear fruit (Opuntia ficus-indica L.) juice. The absorption dynamics and sites of both pigments were investigated by LC-MS or DAD-HPLC using portal blood collected at five to ten minute intervals over a 30-min period after intubation in ligated gastric or small intestinal loops in rats. The antioxidant capacities of both pigments were measured using the ORAC assay. Indicaxanthin and betacyanin showed a maximum serum concentration at 5 or 10 minutes, respectively, after injection into the small intestine in rats. Moreover, betanin and its isomer were absorbed from both the stomach and small intestine. On the other hand, indicaxanthin was absorbed from the small intestine, but not from the stomach. However, the antioxidant capacity of indicaxanthin in vitro was higher than that of betacyanin (13.6 and 4.2 mmol TE/g, respectively). These results indicate that both pigments may be absorbed from the gastrointestinal tract via different pathways.

Texture and unsaccharified residual starch contents in steamed storage roots of 6 sweet potato cultivars with different levels (high, moderate and extremely low) of beta-amylase activity were investigated. In the cultivars with high activity (“Beniharuka” and “Himeayaka”), the residual starch content in steamed roots was about 47% of that in their fresh roots. Comparatively, these values were 62% in the cultivars with moderate activity (“Tamayutaka” and “Kokei 14”) and 93% in the cultivars with extremely low beta-amylase activity (“Okikogane” and “Satsumahikari”). The decrease in starch content during steam-cooking was nearly equal to the amount of starch degradation estimated from the maltose concentration of steamed roots, and the rate of starch degradation was highly correlated with the beta-amylase activity of fresh roots (r=0.77***, n=34). The texture of steamed sweet potato roots showed a higher correlation with the concentration of unsaccharified residual starch after degradation by beta-amylase than with the starch concentration in their fresh roots. In the cultivars with extremely low beta-amylase activity, the starch concentration of storage roots hardly changed after steaming because of the extremely low starch digestion by beta-amylase, resulting in a mealy texture of the steamed roots.

In order to promote the circulation of fresh scallops, cold-stored fresh scallops were subjected to sensory evaluation and volatile-compound analysis. Experiments were performed with six individual parts (skeletal adductor muscle, smooth adductor muscle, gonad, gill, midget gland and mantle) of fresh scallops stored at 5°C for 2 days. The effects of cold storage on odor and degradation levels, as indicated by the levels of volatile compounds, were analyzed. The odor level of each part increased with each day of storage. However, the degree of degradation varied across the six parts studied. Gas chromatograph mass spectrometer (GC-MS) analysis showed that the levels of volatile compounds increased in proportion to the level of odor. The main volatile compounds detected by GC-MS included dimethyl sulfide, (5Z)-octa-1,5-dien-3-ol, 1-penten-3-ol and hexanal. The quantities of these volatile compounds differed across the different parts. It is likely that these volatile compounds were responsible for the odor of the fresh parts. The level of unpleasant smell and volatile basic nitrogen concentration (VB-N) showed a positive correlation (p<0.01). Therefore, VB-N may be useful as an index for freshness level of scallop odor.

An interlaboratory study on the evaluation methods of astringent and umami taste intensities of Japanese leaf-type green tea using a taste sensor system was performed. Repeatability and reproducibility were calculated based on data from eight laboratories. When the sensor output difference between two standard substance solutions whose concentrations were 1.44-fold different was set as one unit in the evaluation scale for taste intensity, maximum reproducibility tolerances did not exceed one unit on this scale.

In this study, vinegar extract was produced from the waste peels of Shiikuwasha, which contains characteristic ingredients such as polymethoxyflavones (PMFs) and is applicable for commercialization as a seasoning product. The results of this study are:

(1) After the seeds and segment membranes were removed from the residual substances from juice production, the peels were extracted using spirit vinegar without drying, resulting in a vinegar extract contained PMFs. Also, the vinegar extract was characterized by minimal amounts of limonin and low bitterness.

(2) A ratio of 20% (w/w) waste peels to 80% (w/w) spirit vinegar was employed, and the resultant vinegar extract contained 7.5mg/100mL nobiletin. The optimal extraction process was performed 4-5 times in ten seconds.

(3) During storage at ambient temperature, the PMFs content was stable, but monoterpenes decreased sharply and monoterpene alcohols decreased gradually.

This study aimed to investigate the effect of heated gluten on the bread-making qualities of Yudane dough. Yudane is a type of bread dough made by mixing boiling water with flour. Various bread-making tests were performed using non-heated wheat starch and heated freeze-dried gluten, which was used to imitate Yudane dough. The imitation Yudane dough was prepared by mixing heated gluten (prepared by heating a mixture of freeze-dried gluten and water from 55 to 80°C in increments of 5°C) with non-heated wheat starch. The imitation Yudane dough was then added to flour dough at 20% (w/w, flour base). Compared with the control dough (without heated gluten), the dough mixed with imitation Yudane dough (with heated gluten) had longer dough development time, and higher gas retention and specific loaf volume. These improvements in bread-making quality were mainly related to the partially denatured gluten present in the imitation Yudane dough. In addition, the bread made with imitation Yudane dough (including denatured gluten) showed a slow staling rate, attributable to the increased molecular weight of the heated gluten compared to the native gluten.

Japanese sake was concentrated to a high quality using progressive freeze concentration (PFC). A market sake (seishu) was concentrated using a cylindrical PFC test apparatus, and the alcohol content increased from 12.5 to 24.0 vol-%. A market sake malt (genshu) was concentrated using a tubular ice system for the scale-up of PFC, and the alcohol content increased from 17.0 to 27.1 vol-%. The distribution of organic acids and flavors was measured, and no substantial changes were observed in the component profiles before and after the concentration by PFC. The findings show that PFC can be used to produce new-types of concentrated alcoholic drinks, including Japanese sake, as an alternative to conventional evaporation, in which the component profiles differ drastically before and after concentration.

Japan has become a “super-aged society” in which over 21% of the population is aged≥65 years. Many Japanese people are seeking functional foods that can prevent age-related diseases. Thus, we developed and applied a method of evaluating anti-aging foods based on age-related hearing loss (AHL) in mice. We found that the intake of a diet containing whole egg (8% or 20% of the diet) or 13.6% egg yolks for 6 months delayed the development of AHL, whereas a diet containing 6.4% egg whites had no effect. This indicates that egg yolk has the potential to prevent age-related diseases.

Eggs of the Nagoya breed of chickens are characterized by a bright cherry blossom-colored eggshell and a thick, full-flavored yolk. The eggshell is covered by white spots of calcium carbonate, while the yolk has a deep color and a higher ratio of yolk weight compared to that of White Leghorn chickens. As for nutritional characteristics, the lipid content of the yolk is significantly higher in Nagoya compared to that in White Leghorn. As for physical characteristics, the yolk viscosity of eggs is higher in Nagoya than that in White Leghorn. Recent findings using an artificial taste sensor revealed the high umami taste intensity of Nagoya egg yolk compared to that of White Leghorn. As for processing properties, the emulsifying ability of the yolk of Nagoya is superior to that of White Leghorn. The hardness and elastic modulus are high in the boiled eggs of Nagoya compared to those of White Leghorn. From these findings, Nagoya eggs are characterized by the yolk. Thus, it is proposed that this characteristic is one of factors responsible for the palatability of eggs of Nagoya chickens.