Threshold of toxicological concern(TTC) concept has been applied by JECFA which was established by the cooperation of FAO and WHO and it is the method to evaluate the toxicity of environmental chemicals and to determine human exposure threshold value by the chemical structures and the reliable exposure estimates which does not affect the human health. The characteristics of flavoring substances are often the components of usual food, known chemical structures, very low dose exposure, and the lacking toxicological data of many of them. TTC concept has been utilized for the risk assessment of flavoring substances in U.S. and Europe and the decision trees for the assessment process are different between Japan and U.S. or Europe. Now-a-days, great attentions have been paid by consumers to the safety of food containing flavoring substances and therefore, it is important issue to supply the exact knowledge for the safety of flavoring substances per se to the consumers. In this paper, it is discussed that the test systems of flavoring substances for risk assessment by collecting useful information internationally. It is considered that the risk assessment of flavoring substance might be performed in the different way from that of other environmental and intended to be proposed decision tree using TTC concept for flavoring substances.

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Proanthocyanidins and artificial tannin-like compounds, with high molecular weights and many hydroxy groups, are present as phytochemicals in foods and beverages as well as biter taste compounds and colour pigments. Our knowledge of their content, composition, chemical and physical properties, and physiological functions are increasing with the development of analytical methods. Recently, many studies have also focused on their functionalities in fields such as anti-oxidative activity; however, the information on their bioavailability and the mechanism of their functions remains limited. In this review, the chemical and structural properties of proanthocyanidins and artificial tannin-like compounds were described. The functions and bioavailability of procyanidins, and the relationships between the structures of procyanidins, in particular the degree of polymerization, and their functions also were described.

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In Europe, semicarbazide (SEM) was detected from bottled baby foods. SEM is a thermal degradation product of azodicarbonamide which is a foaming agent for plastic gaskets on metal lids. In this paper, a determination method of SEM by the incremental standard addition technique was established. And SEM in 64 of bottled foods marketed in Japan were surveyed. In the bottled baby food, SEM was detected 5.7-46.7 μg/g in 9 samples, and not detected in 2 samples. This contamination level is almost the same as that of the investigation in EU. In the general bottled food, SEM was detected 0.6-45.2 μg/g in 23 samples, and not detected in 30 samples. This level was slightly higher compared with that of EU. In all the bottled foods containing SEM, SEM or hydrazodicarbonamide was detected also from their sealing gasket. These results indicate that SEM detected from bottled food is degradation product of ADC added to the sealing gasket.

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In recent years, various products of non-controlled psychotropic plants have become popular in place of chemical psychotropic substances, which are now subject to stricter controls, and they are causing concern in Japan. To survey current trends in the abuse of psychotropic plants, 127 kinds of plant products (which were distributed from April 2004 to May 2007 in Japan) were analyzed using LC-ESI-MS. As a results of the analyses, 6 typical psychotropic plant components, N,N-dimethyltryptamine (DMT) (1.2% contents in the sample), mescaline (0.1-1.7%), salvinorin A (0.1-4.5%), lysergamide (LSA) (0.005-0.4%), harmine (0.04-3.1%), and harmaline (0.008-4.5%) were determined in the 51 products. Although one-third of the products were mixtures of several plant materials or they did not list their ingredients, the raw materials of some products could be estimated by the determination of the typical plant's components. On the other hand, the compounds in some products were not consistent with the ingredients listed on the products. The products which contained raw materials exclusively used as pharmaceuticals were also found to be distributed. Moreover, the contents of the active compounds in some products were sufficient to produce hallucinogenic effects in humans and there is concern about the damage to the health of their users. The proposed analytical method could be useful in the investigation of these plant products in the market.

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Amino acids are authorized food additives commonly used as seasonings, dietary supplements and quality-retaining agents. We have developed a chromatographic method of analyzing racemic acids using HPLC with UV detection. The HPLC conditions were as follows : column 1, SUMICHIRAL OA-5000 (particle type, 5 μm, 4.6 mm i.d. × 150 mm) : column 2, SUMICHIRAL OA-5000 (monolithic type, 4.6 mm i.d. × 100 mm) : mobile phase A, 0.5 mM〜2 mM CuSO₄・5H₂O solution : mobile phase B, 2 mM CuSO₄・5H₂O in water and isopropyl alcohol solution : flow rate, 0.8 mL/min or 1.0 mL/min : detection, UV 254 nm. We separated each racemate of Asn, Cystine and Ser by using the combination of particle type column and monolithic type column. The other racemates were separated by using particle type column alone. The detection ratio of D/L of each amino acid, the limited lower concentration of D-enantiomer for 100 μg/mL of L-enantiomer in simultaneous analysis, were analyzed. The ratios of Glu, Asn, Cys, Thr and Trp were 0.1, and that of the other amino acids were under 0.01. The quantitative limit of D/L-Cys were 10 μg/mL, and the limits of the other amino acids were under 1 μg/mL.

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Green tea (Camellia sinensis) aqueous extracts were autoclaved and then fermented with three strains of fungi (Penicillium sp., Fusarium solani or Rosellinia necatrix) respectively. Gallate type catechins (epigallocatechin gallate, gallocatechin gallate, epicatechin gallate, catechin gallate) rapidly decreased at the first 7days of the fermentation. Non-gallate type catechins (gallocatechin, epigallocatechin, epicatechin and catechin) slightly increased during the first 7 days of the period, but they also gradually decreased in all the fermented extracts. Esterase activities originated from these fungi seemed to be strong during fermentation and they caused the rapid degradation of ester linkage of the gallic acid moiety of gallate type catechins. During the fermentation period of 35 days, the concentration of caffeine stayed at a high level (0.55 - 0.75 mg/ml) in all of the extracts. Only in the extract treated with F. solani, rutin concentration increased up to 0.32 mg / ml on the 28th day of the fermentation period. From the tea extract treated with F. solani, blumenol B which has not been detected in various tea products was also isolated together with rutin.

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