@article{oai:repo.qst.go.jp:00045298,
 author = {Ogiyama, Shinichi and Tagami, Keiko and Uchida, Shigeo and 荻山 慎一 and 田上 恵子 and 内田 滋夫},
 issue = {16},
 journal = {Nuclear Instruments & Methods in Physics Research Section B},
 month = {Aug},
 note = {The concentration and distribution of essential elements in brown rice grains (Oryza sativa L. var. japonica) associated with the polishing rate was determined. Rice samples were collected in Japan and polished to 5, 10, 15, and 20 % loss of the total weight of brown rice. Concentrations of 8 essential elements (P, K, Ca, Mg, Cu, Fe, Mn, and Zn) were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES), and distributions of the elements in a single grain were visualized as elemental distribution maps of a cross section by micro particle induced X-ray emission (Micro-PIXE) analysis. Results of ICP-AES analysis indicated that in rice which polished from 0 to 10 % loss of weight, there were 3 patterns in the P/B ratio, which is the mean concentration of an element in polished rice divided by that of the element in the brown rice: no change (Cu and Zn), a gradual decrease (P, Mg, Mn, and Fe), and a decrease after a constant phase (Ca and K). There was no remarkable change of the P/B ratio in rice grains which polished from 10 to 20 % loss of weight. Micro-PIXE analysis images showed that P, K, Ca, Mg, Fe, and Mn were present in large amounts in the surface layer (approx. <200um thickness) of brown rice. Two sub-layers were mainly recognized in the grain surface layer in the elemental distribution maps of a cross section. The first sub-layer was approximately 130-170 um thick. The second sub-layer was approximately 20-50 um thick, and the primary part of the grain (endosperm cells and starch granules) was under it. The images showed Cu and Zn were uniformity distributed in brown rice, and their concentrations of polished rice were not affected by the polishing rate. Although ICP-AES measurements could not provide the detail structure of the surface layer of the rice grains, the trend of concentration of the elements generally agreed with the elemental distribution maps obtained Micro-PIXE analysis.},
 pages = {3625--3632},
 title = {The Concentration and Distribution of Essential Elements in Brown Rice Associated with the Polishing Rate: Use of ICP-AES and Micro-PIXE},
 volume = {266},
 year = {2008}
}