Stilbenes, in particular trans-resveratrol and its glucoside, are widely reported to be beneficial to health, having been shown to possess antioxidative, anticarcinogenic, and antitumor properties. Major dietary sources include grapes, wine, peanuts, and soy; however, they can also be introduced into the diet through Itadori tea, which has long been used in Japan and China as a traditional herbal remedy for heart disease and strokes. Analysis of grapes, peanuts, and Itadori tea shows that they contain mainly trans-resveratrol glucoside. In contrast, red wines are primarily a source of the aglycones cis- and trans-resveratrol. While peanuts and grapes contain low levels of the stilbenes, Itadori tea and red wine both supply relatively high concentrations of resveratrol. For people who do not consume alcohol, Itadori tea may be a suitable substitute for red wine. However, further study on the potential biological effects of other endogenous compounds in Itadori tea is required and there is also a need for more information on the absorption and in vivo biomedical actions of free and conjugated resveratrol.

This review provides details on the phytochemicals in green coffee beans and the changes that occur during roasting. Key compounds in the coffee beverage, produced from the ground, roasted beans, are volatile constituents responsible for the unique aroma, the alkaloids caffeine and trigonelline, chlorogenic acids, the diterpenes cafestol and kahweol, and melanoidins, which are Maillard reaction products. The fate of these compounds in the body following consumption of coffee is discussed along with evidence of the mechanisms by which they may impact on health. Finally, epidemiological findings linking coffee consumption to potential health benefits including prevention of several chronic and degenerative diseases, such as cancer, cardiovascular disorders, diabetes, and Parkinson's disease, are evaluated.

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A large amount of gamma-aminobutyric acid (GABA) was found to accumulate in tomato (Solanum lycopersicum) fruits before the breaker stage. Shortly thereafter, GABA was rapidly catabolized after the breaker stage. We screened the GABA-rich tomato cultivar 'DG03-9' which did not show rapid GABA catabolism after the breaker stage. Although GABA hyperaccumulation and rapid catabolism in fruits is well known, the mechanisms are not clearly understood. In order to clarify these mechanisms, we performed comparative studies of 'Micro-Tom' and 'DG03-9' fruits for the analysis of gene expression levels, protein levels and enzymatic activity levels of GABA biosynthesis- and catabolism-related enzymes. During GABA accumulation, we found positive correlations among GABA contents and expression levels of SlGAD2 and SlGAD3. Both of these genes encode glutamate decarboxylase (GAD) which is a key enzyme of GABA biosynthesis. During GABA catabolism, we found a strong correlation between GABA contents and enzyme activity of alpha-ketoglutarate-dependent GABA transaminase (GABA-TK). The contents of glutamate and aspartate, which are synthesized from GABA and glutamate, respectively, increased with elevation of GABA-TK enzymatic activity. GABA-TK is the major GABA transaminase form in animals and appears to be a minor form in plants. In 'DG03-9' fruits, GAD enzymatic activity was prolonged until the ripening stage, and GABA-TK activity was significantly low. Taken together, our results suggest that GAD and GABA-TK play crucial roles in GABA accumulation and catabolism, respectively, in tomato fruits.

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Theanine (γ-glutamyl-L-ethylamide) is the most abundant non-protein amino acid in tea leaves. In addition to Camellia sinensis, theanine occurs in several plants belonging to the Ericales. Biosynthesis of theanine from glutamic acid and ethylamine by theanine synthetase is present in all organs of tea seedlings, but roots are the major site of theanine biosynthesis in adult tea trees. Theanine is transported from roots to young leaves via the xylem sap. Theanine is hydrolysed to glutamic acid and ethylamine in leaves. Ethylamine produced from theanine is predominantly used for catechin biosynthesis. Concentration of ammonia and light intensity influence the biosynthesis and degradation of theanine, respectively. Biosynthesis, translocation and degradation of theanine and related enzymes and genes are reviewed.