26 巻 (2015) 1 号 p. 23-26
To evaluate a validity of values for manganese (Mn) and molybdenum (Mo) contents of rice described in the Standard Tables of Food Composition in Japan 2010, 15 samples of Japanese brown rice, 53 samples of Japanese polished rice and 10 samples of Chinese polished rice were collected and their Mn and Mo contents were measured. Mean values of Mn in the Japanese brown rice and polished rice were 1.90 and 0.81 mg/100 g, respectively, which were close to values described in the Standard Tables. Mean value of Mn in the Chinese polished rice was 0.77 mg/100 g, which was also close to the values in the Standard Tables. Among the 53 samples of Japanese polished rice, 45 samples (84.9%) showed the Mn contents ranged from 0.6 to 1.0 mg/100 g. These results indicate that the Mn values of rice described in the Standard Tables are highly reliable. On the other hand, mean values of Mo in the Japanese brown rice and polished rice were 63 and 59 µg/100 g, respectively, which were also close to the Standard Tables. However, 42 samples (79.2%) of the Japanese polished rice showed the Mo content of less than 65 µg/ 100 g and a little sample showed more than 2 times of the values of the Standard Tables. Molybdenum contents in the Chinese rice showed higher values and variation than the Japanese rice. These results indicate that a large part of the Japanese rice showed a little lower Mo value than one described in the Standard Tables.