[Simultaneous analysis of residual pesticides in fruit, vegetables, brown rice, and oolong tea by LC-MS/MS].

According to "The validity evaluation guideline of the testing methodology on the residual pesticides in food" of the Ministry of Health, Labour and Welfare of Japan, we carried out validity evaluation of a simultaneous analysis method for residual pesticides in various products with the QuEChERS method using a C18 mini column and/or an EnviCarb/PSA mini column for purification. Multi-ingredient simultaneous analysis with high sensitivity in a short time was achieved with LC-MS/MS. Validation was achieved for 269 pesticides among 302 pesticides in eight kinds of fruit, vegetables, and brown rice and 204 pesticides among 233 pesticides in oolong tea. Finally, 151 pesticides in oolong tea and from 234 to 259 pesticides in fruit, vegetables, and brown rice met the values specified in the guideline.

Monitoring of radioactive substances in foods distributed in Kyoto, Japan (1991-2011). - Comparison of detection rates and concentrations before and after the Fukushima Daiichi Nuclear Power Plant accident - .

Since the Chernobyl Nuclear Power Plant accident, radioactive substances have been continually monitored in foods collected in the city of Kyoto, Japan. The importance of the monitoring was increased by the Fukushima Daiichi Nuclear Power Plant accident in March 2011. Here, the detection rates and concentrations of radioactive substances were compared among food samples collected before and after the accident in Fukushima prefecture. Before the accident, (137)Cs was the only radioactive substance detected in foods. The detection rate was 70% for fish and shellfish samples and the highest concentration was 1.7 Bq/kg. It was also 83% for fresh mushroom samples and the highest concentration was 7.5 Bq/kg. In contrast, the detection rate was low for vegetables and the concentrations were also lower than those of the above samples. On the other hand, after the accident, (131)I was detected in food produced in the Tohoku and Kanto areas. Actually, (131)I (3,400 Bq/kg), (134)Cs (280 Bq/kg), and (137)Cs (280 Bq/kg) were detected in mizuna, a leaf vegetable, on March 23, 2011. These radioactive substances were detected in all leaf vegetable samples examined in March and April 2011, but they were not detected in samples examined in November 2011. (131)I was not detected in any food sample examined after May 2011. However, (137)Cs (average=7.9 Bq/kg) was consistently detected in fish and shellfish samples until November, although the concentrations were less than the regulatory limits. It appears unlikely that foods containing radioactive substances over the regulatory limits are currently being distributed in Kyoto.

Anti-obesity effects of the methanolic extract and chakasaponins from the flower buds of Camellia sinensis in mice.

The methanolic extract from the flower buds of Camellia sinensis cultivated in Fujian Province showed inhibitory effects on body weight gain and the weight of visceral fats in high-fat diet-fed mice and/or Tsumura Suzuki Obese Diabetic (TSOD) mice. A suppressive effect of the extract on food intake was suggested to contribute to the anti-obesity effect. The n-butanol (BuOH)-soluble fraction also reduced food intake in normal diet-fed mice. A principal constituent, chakasaponin II, inhibited gastric emptying (GE) as well as food intake. These inhibitory effects were partly reduced by pretreatment with a high dose of capsaicin. The n-BuOH-soluble fraction and chakasaponin II suppressed mRNA levels of neuropeptide Y (NPY), an important regulator of body weight through its effects on food intake and energy expenditure, in the hypothalamus. Furthermore, chakasaponin II enhanced the release of serotonin (5-HT) from the isolated ilea of mice in vitro. These findings suggested that the active saponins suppressed the appetite signals in the hypothalamus through stimulation of the capsaicin-sensitive sensory nerves, probably vagal afferent nerves, or enhancement of 5-HT release from the ilea, leading to reduced food intake and body weight gain.