The aim of this study was to investigate the composition and contents of anthocyanins and proanthocyanidins, and the antioxidant capacity of black and red cowpeas grown in Japan, with comparison to grain legumes (black kidney beans, black soybeans, and azuki beans) commonly consumed in Japan. This study revealed that black cowpeas contained seven anthocyanins, the 3-O-galactosides and 3-O-glucosides of cyanidin and delphinidin, and the 3-O-glucosides of malvidin, peonidin, and petunidin, at higher levels than other grain legumes. In addition, black and red cowpeas were rich in proanthocyanidin oligomers (monomers to hexamers) when compared with other grain legumes. Among these, black and red cowpeas showed potent hydrophilic oxygen radical absorbance capacity (H-ORAC), reaching 540.6 and 367.5 μmol-Trolox equivalents/g-dry matter, respectively. The contributions of anthocyanins and proanthocyanidin oligomers to H-ORAC values were 45.8 % and 17.5 % in black and red cowpeas, respectively.

The effect of the intake of apple vinegar containing yuzu juice on psychological stress was investigated in healthy young women. The subjects used in this study were １ ６ healthy female university students(２ ２ ± １ years old) , who ingested １ ０ ０! of the apple vinegar drink twice a day (before breakfast and before supper)for ３ weeks. Next, the changes in the mental stress indices of the group that consumed the drink were compared to those of the control group. In the test, the subjects ingested １ ０ ０! of the test beverage. ３ ０ minutes after the ingestion, they were subjected to a stressor, which was a simple mental task. After this, they were given a ６ ０-min rest. Blood flow and heart rate variability measurements, electroencephalography, and a visual analog scale (VAS) were used to determine the mental stress indices. The blood flow, parasympathetic nerve activity index, and alpha/beta ratio in the group that consumed the drink were significantly higher than those in the control group. There was a correlation between blood flow and alpha waves. From these results, the apple vinegar drink was shown to have a psychological stress-reducing effect.

In order to investigate the properties of frozen concentrated orange juice from 5 countries imported into Japan, we evaluated colorimetric value, glucose, fructose, sucrose, citric acid, L-malic acid, D-isocitric acid, L-ascorbic acid, flavonoids, and headspace volatile flavor components by principal component analysis. The products from Brazil contained a large amount of glucose and fructose, while the products from Belize had much more sucrose content. In addition, products from Israel contained high amounts of organic acids. The content of flavonoids depended on the country of origin and were not detected in products from Israel. The flavor component contained the largest amount of d-limonene in all the samples. Principal component analysis using 59 data items showed that the flavor components strongly contribute to the first principal component, and that sugars and flavonoids contribute to the second principal component. In a scatter plot using the principal component scores, products from Brazil and America were divided into two groups, but generally products were gathered and distributed by country of origin. The data analyzed in this study demonstrated that concentrated orange juice products from the same country contained similar components, suggesting that each country of origin has unique differences in components.