The characteristics of flavonoids and coumarins in ten types of lemon (Lemon, Pink-lemonade, Meyer lemon, Ogasawarashima lemon, Hachijyo fruit lemon, Alen-eureka lemon, Lisbon, Vilafranca, Sweet lemon, Ponderosa) were examined. Twelve flavonoids and seven coumarins from the peel and juice of the different lemon types were analyzed using HPLC, and the quantitative values were subjected to a multivariate statistics principal component analysis. The ten lemon types were separated into four (I ～ IV) categories, corresponding to genus-species in plant classification (Citrus limon, Citrus meyeri, Citrus limetta, Citrus pyriformis), based on the scatter diagram of the score plot from the principal component analysis. Lemon, Pink-lemonade, Alen-eureka lemon, Lisbon, and Vilafranca were in category I: C. limon. Meyer lemon, Ogasawara-shima lemon, and Hachijyo fruit lemon were in category II: C. meyeri. Sweet lemon (C. limetta) was in category III, and Ponderosa (C. pyriformis) was in category IV. The characteristic flavonoids in the lemon types of category I were eriocitrin, diosmin, 6,8-C-diglucosylapigenin, and 6,8-C-diglucosyldiosmetin. Those of category III were narirutin, nobiletin, and tangeretin, and those of category IV were neoeriocitrin, neohesperidin, and naringin. Coumarins were not found in the juices but were found in the peels. The characteristic coumarins in the category I lemon types were 8-geranyloxypsolaren, 5-geranyloxypsolaren (bergamottin), and 5-geranyloxy-7- methoxycoumarin. That of the category II lemon types was 7-methoxy-5-prenyloxycoumarin, and that of the category IV types was 7-geranyloxycoumarin (auraptene). The antioxidative activity for the peel extract of the category I lemon types was the highest activity of all categories (p < 0.05) suggesting a relationship to the eriocitrin and neoeriocitrin content.

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Although enteral nutrition has become more widely used in nutritional therapy, there are complications associated with nutritional support through tube feeding, including diarrhea, gastroesophageal ref lux, and vomiting. To prevent these complications, some dietary fibers have been added to enteral nutrition formulas. In this study, we verified the fundamental physiochemical properties of the dietary fibers used in enteral nutrition formulas. We found that sodium alginate (SA) had the highest viscosity and the longest drying time, while had more water holding capacity than other dietary fibers, including resistant maltodextrin, partially hydrolyzed guar gum, soy dietary fiber, and low methyl ester pectin (LMP). LMP and SA was solidified by artificial gastric juice. These results suggest that SA in enteral nutrition formulas is solidified in the stomach. Therefore, its use may reduce the risk of gastroesophageal reflux and vomiting. SA was less fermented, indicating that it has a high molecular weight in the colon, thereby maintaining its viscosity and water-holding capacity, and thus contributing to maintaining fecal volume.

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The effect of sodium carboxymethyl cellulose (CMC), a food additive used as a thickener and emulsion stabilizer, on detection of genetically modified (GM) foods was evaluated. The addition of CMC to processed rice foods at 2% (w/w) concentration inhibited the yield of DNA in the DNA purification step by up to 40% and 70% using ion-exchange resin-type DNA purification kit and silica membrane-type DNA purification kit, respectively. The DNA yield from the rice vermicelli commodities containing CMC was significantly lower than that from the CMC-free rice vermicelli commodities. When 2% (w/w) CMC was contained in the rice flour with < 5,000 copies of transgenic genes for GM rice, the false negative rate in the real-time polymerase chain reaction detection targeting the genes was more than 10%. The CMC attenuates the DNA purification efficiency from the rice food samples, and may interfere with the GM rice testing using DNA samples prepared from processed rice foods containing CMC.

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An analytical method for the determination of histamine in fish meal by LC-MS/MS was developed. Histamine was extracted with 5% trichloroacetic acid. The extract was neutralized and cleaned up with a weak cation ion exchange cartridge (WCX) column. The cartridge was washed with water and methanol, and histamine was eluted with methanol-water (1:1) solution containing 2 % formic acid. Histamine in the eluate was measured by LC-MS / MS. The LC separation was carried out on a Triart Diol-HILIC plus column with a linear gradient of 0.1% formic acid and acetonitrile. MS was carried out in the positive ion electrospray ionization mode. Recovery tests of histamine from seven kinds of fish meal and four kinds of assorted feed were 79.6 to 116%, and the relative standard deviation were 1.9 to 10.3%. The limits of quantitation of the developed method was 5 mg/kg.

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A method for analysis of okadaic acid (OA), dinophysistoxin-1 (DTX1) and dinophysistoxin-2 (DTX2) using deproteination cartridge filter was developed. This is a simple method because it does not require complicated operations such as conditioning and washing of the column. The shellfish poisons in oyster were extracted with methanol and methanol/water (9:1), and were hydrolyzed with 2.5 mol/L sodium hydroxide solution. The crude extracts were defatted by liquid- liquid partition using n-hexane, and were passed through a deproteination cartridge filter. Measurement was performed by liquid chromatography tandem mass spectrometry. As a result of the validation study using the matrix calibration curve method, the trueness, repeatability and withinlaboratory reproducibility were 92-98, 1.0-3.0 and 2.0-4.0%, respectively, and met the target values of notification of Ministry of Health, Labour and Welfare of Japan.

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Pyrrolizidine alkaloids are products of secondary metabolism in plants. They have been detected in honey, as well as in herbal and green tea. However, these molecules are toxic and carcinogenic, and hence, their presence in commercial products should be regulated. In this study, a quantitative analytical method for the detection of 19 pyrrolizidine alkaloid compounds in bottled tea and tea leaves was developed. The samples were prepared via the QuEChERS method and the analysis was performed with a tandem of high performance liquid chromatography and mass spectrometry. Monitoring tests were conducted on commercially available bottled tea and tea leaves. The results showed that in Japanese commercial bottled tea, all pyrrolizidine alkaloids were below the detection limit. Tea leaves experiments, in contrast, revealed that some types of tea (rooibos and chamomile) contain pyrrolizidine alkaloids.

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Rosemary extract is one of the natural food additives on the List of Existing Food Additives used in Japan. There are two types of rosemary extract products on the Japanese market: water-soluble type and water-insoluble type. Since the two types are thought to have different chemical compositions, investigation of their compositions is essential in order to ensure the safety and efficacy of the products. In this study, LC/MS and GC/MS analyses were performed on products distributed as rosemary extract on the Japanese market. The results showed that carnosol and carnosic acid, which are thought to be main components of rosemary extract, were only present in the water-insoluble-type products. Many kinds of volatile compounds were also detected in the waterinsoluble- type products, and the ratios of these compounds varied even among the products having similar amounts of carnosol and its relatives. In the water-soluble-type products, rosmarinic acid and flavonoids were observed instead of carnosol, carnosic acid and volatile compounds.

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