The functionality and content of functional components in foods need to be measured precisely. We have improved methods to evaluate the antioxidant capacity of foods based on oxygen radical absorbance capacity, and the content of quercetin in onions and isoflavones in soybeans. The precision of these methods was validated by inter-laboratory tests in accordance with internationally standardized protocols. These methods enable precise evaluation of antioxidant capacity and content, and the values are comparable. In this review article, the validated methods are introduced and the possible applications of the methods are discussed.

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.

Chrysanthemum flower extract has anti-inflammatory and neuroprotective effects on microglia, which play a central role in immune regulation in the brain. However, the exact immune regulatory activity of this extract on microglia requires clarification. The aim of this study was to investigate the different modes of regulating microglial TNF-α production by extracts of two cultivars of edible Chrysanthemum, Aboukyu and Enmeiraku, in relation to differences in the composition ratio of triterpenoids. GCMS analysis showed that the majority of compounds in hexane-soluble extracts were common between cultivars; however, the composition ratios of the triterpenoids faradiol and heliantriol C fatty acid esters in Aboukyu appeared to be lower than in Enmeiraku. Inhibition and promotion of microglial TNF-α production by hexane-soluble extracts of two Chrysanthemum cultivars were investigated at concentrations below 100µg/mL, which showed no apparent cytotoxicity. The Enmeiraku extract suppressed TNF-α production stimulated by LPS in a concentration-dependent manner, but did not alter ATP-stimulated TNF-α production. Conversely, the Aboukyu extract did not suppress LPS-stimulated TNF-α production, but increased ATP-stimulated TNF-α production. Because the Enmeiraku extract potently suppressed LPS-stimulated activation of IκB phosphorylation, it may attenuate TNF-α production mediated through NF-κB signaling blockage. This study suggests that the different effects Aboukyu and Enmeiraku extracts have on microglial TNF-α production are attributable to differences in the composition ratio of triterpenoids.

Fermented brown rice and rice bran with Aspergillus oryzae (FBRA) is a processed food prepared from brown rice and rice bran. Although FBRA α-amylase activity is monitored as an indicator of fermentation, the evaluation of FBRA quality remains insufficient. We non-targetedly compared metabolite profiles in accepted FBRA, defective FBRA, and unfermented materials using ¹H-NMR coupled with principal component analysis (PCA). Accepted FBRA was clearly separated from defective FBRA and unfermented materials. We also compared twenty-five accepted FBRA samples, where PCA showed that plotting of accepted FBRA results in dispersion that is unbiased toward different production dates and different fermentation apparatuses. These results indicated that accepted FBRA is manufactured with a consistent quality.