As a result of the Fukushima Daiichi nuclear power plant (NPP) accident, various radionuclides were released into the environment. In this study, we surveyed strontium-90 (90Sr) concentrations in several foodstuffs. Strontium-90 is thought to be the third most important residual radionuclide in food collected after the Fukushima Daiichi, NPP accident after following cesium-137 (137Cs) and cesium-134 (134Cs). Results of 90Sr analyses indicated that 90Sr was detect in 25 of the 40 radioactive cesium (r-Cs) positive samples collected in areas around the Fukushima Daiichi NPP, ranging in distance from 50 to 250 km. R-Cs positive samples were defined as containing both 134Cs and 137Cs which are considered to be indicators of the after-effects of the Fukushima Daiichi NPP accident. We also detected 90Sr in 8 of 13 r-Cs negative samples, in which 134Cs was not detected. Strontium-90 concentrations in the r-Cs positive samples did not significantly exceed the 90Sr concentrations in r-Cs negative samples or the 90Sr concentration ranges in comparable food groups found in previous surveys before the Fukushima Daiichi NPP accident. Thus, 90Sr concentrations in r-Cs positive samples were indistinguishable from the background 90Sr concentrations arising from global fallout prior to the Fukushima accident, suggesting that no marked increase of 90Sr concentrations has occurred in r-Cs positive samples as a result of the Fukushima Daiichi NPP accident.
Antioxidant activities of aqueous extracts prepared from powdered leaves and stems of Salacia reticulata, a Salacia plant that grows in Sri Lanka, were investigated. Lipid peroxide levels and some hepatic injury markers in plasma, liver and/or kidney of mice treated with ferric nitrilotriacetate (Fe-NTA) were increased as compared to those of control mice. Oral preadministration of extracts of Salacia leaves and stems at doses of 100, 200 and 400 mg/kg body weight prevented the elevations of lipid peroxides and injury markers in a dose-dependent manner. Decrease of antioxidant activity in plasma of mice treated with Fe-NTA was also prevented by administration of these extracts. In in vitro study, well-known polyphenol components exhibited antioxidant activities, but other effective components were also present in these extracts. The results of this investigation indicate that the extracts of leaves and stems of S. reticulata could be beneficial as health foods for the prevention of oxidative stress-related disorders.
The number of students with food allergy is currently increasing. Moreover, the unintentional mixing or accidental ingestion of allergy-causing food materials in school lunches has attracted great attention. The aim of this study was to verify the current status of elementary school lunch provision for students with food allergy. We investigated the elementary school lunch services in seven cities in Osaka prefecture. The egg elimination diet was provided in five of the seven cities. In four of these five cities, we did not detect the presence of egg residue either on the surface of various cookware used to prepare the egg elimination diet or in the food itself. In this investigation, the egg elimination diet was provided properly, but we observed differences among the cities in the manual preparation of foods for food allergy diets. To step up these efforts, our results suggest the necessity of preparing a manual to consider individual conditions of school lunch services.
The interaction of warfarin and vitamin K is a clinically significant issue. This study investigated the acceptable intake level of vitamin K among warfarin users by means of a systematic review. We searched two databases (PubMed and “Igaku chuo zasshi”)for articles about adverse events arising from interaction of warfarin and vitamin K, published until October 2014. Of 1,310 citations retrieved, 16 studies met the selection criteria for examination of the upper limit, and 6 studies dealt with amounts below the limit. The intake of vitamin K in warfarin patients was acceptable in the range of 25–325 μg/day, with a maximum daily variation of 292 μg, and a value of 150 μg/day seemed optimum. When these results were applied to usual foods, except for dietary supplements or health foods, the only prohibited foods were fermented soybean (natto) and foods containing it, while green leafy vegetables could be acceptable if their intake is limited.
A headspace-GC analysis method for the determination of residual volatile substances (styrene, toluene, ethylbenzene, isopropylbenzene and propylbenzene) in food contact polystyrene (PS) was evaluated. Ten PS products were analyzed by this headspace-GC method and the Japanese official method, and the values obtained were almost equal. The performance of the method was evaluated, and the trueness, repeatability and reproducibility were 100.4–102.8%, 3.7–6.3% and 6.0–11.1%, respectively. The values of the performance parameters of the headspace-GC method fulfilled the requirements, and this method was confirmed to be extremely precise. Moreover, contamination of the GC equipment was minimized. The residual volatile substances in 58 PS products were surveyed with this method. All products met the specifications defined in the Japanese Food Sanitation Law, and no relationship was found between volatile substances and the sampling year or country of origin.
A determination method of nosiheptide in formula feeds by HPLC-FL was developed and validated, including an inter-laboratory study. Formula feeds were extracted with acetone after adding acetic acid. Liquid chromatographic separation was performed using a ZORBAX Eclipse XDB-C18 column, with acetonitrile and water containing acetic acid as the mobile phase. Detection of NH was carried out with a fluorescence detector. Recovery tests and an inter-laboratory study were conducted using chicken and swine formula feeds fortified with nosiheptide at 0.5–27 mg-potency/kg. Mean recoveries in recovery tests ranged from 91.4 to 103%, and the repeatability in terms of relative standard deviation was within 7.8%. Mean recoveries of the inter-laboratory study ranged from 98.4 to 108%, the repeatability and reproducibility in terms of the relative standard deviations were within 8.1% and 13% respectively, and the HorRat values ranged from 0.21 to 0.75.
Quantitative methods using the matrix-matched standard solutions approach are widely used for multi-residue pesticide determination by GC-MS/MS to deal with the issue of matrix effects. However, preparing matrix-matched standard solutions in analyses of many kinds of samples is very time-consuming. In order to solve this problem, a method that employs general matrix standard solutions has been developed using polyethylene glycol (PEG), extract of vegetables-fruit juice (VFJm) and triphenyl phosphate (named the PEG-VFJm method). Here, a validation study for 168 pesticides was performed on three kinds of samples [potato, spinach and apple] at concentrations of 0.010 and 0.050 μg/g. In these three commodities, 144 to 158 pesticides satisfied the required criteria using the matrix-matched method and 129 to 149 pesticides satisfied the same criteria using the PEG-VFJm method. Our results suggest that application of general matrix standard solutions would enable rapid and effective analyses of pesticides.