title: Composition of chemical species of selenium contained in selenium-enriched shiitake mushroom and vegetables determined by high performance liquid chromatography with inductively coupled plasma mass spectrometry.
abstract: Selenium (Se) species in Se-enriched shiitake mushroom (Lentinula edodes) were identified and quantified by high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICPMS). Two types of Se-enriched shiitake obtained from selenite- or selenate-fertilized mushroom beds were used. More than 80% of Se in both shiitake samples could not be extracted with 0.2 M HCl. Protease digestion released a large amount of selenomethionine from the shiitake enriched with selenite. However, most of the Se in the shiitake enriched with selenate was not released by protease but was released by a cell wall digestive enzyme and most of the Se released was identified as selenate. These results indicate that the main Se species in the shiitake enriched with selenite or selenate is selenomethionine bound to protein or selenate bound to polysaccharides in the cell wall, respectively. Several Se-enriched vegetables grown on a soil fertilized with selenate were also analyzed by HPLC-ICPMS. Four Se species, selenate, Se-methylselenocysteine, selenomethionine, gamma-glutamyl-Se-methylselenocysteine, and an unknown Se compound were detected in the vegetables. The composition of Se species varied with the kinds or parts of vegetables. The main Se species in bulbs, leaves or flowers of the Se-enriched garlic, onions, cabbage and ashitaba were selenate, Se-methylselenocysteine or gamma-glutamyl-Se-methylselenocysteine, while those in fruit bodies of the peppers and pumpkin were selenomethionine bound to protein. Bioavailabilities of Se in the shiitake mushroom enriched with selenite and the vegetables enriched with selenate are expected to be high, but that in shiitake enriched with selenate may be low.
authors.affiliation: Laboratory of Food and Nutritional Sciences, Department of Biotechnology, Faculty of Engineering, Kansai University, Yamate 3-3-3 5, Suita, Osaka 564-8680, Japan. hanmyou4@ipcku.kansai-u.ac.jp
authors.forename: Munehiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Satoru
authors.initials: S
authors.lastname: Sugihara
authors.forename: Yuki
authors.initials: Y
authors.lastname: Inoue
authors.forename: Yûko
authors.initials: Y
authors.lastname: Chihara
authors.forename: Mariko
authors.initials: M
authors.lastname: Kondô
authors.forename: Saori
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Benjama
authors.initials: B
authors.lastname: Sukcharoen
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005308:Fertilizers; D005527:Food, Fortified / Q000032:analysis*; D005737:Garlic / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D019697:Onions / Q000737:chemistry; D010447:Peptide Hydrolases / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry; D064586:Selenic Acid; D012643:Selenium / Q000032:analysis*; D018036:Selenium Compounds / Q000032:analysis*; D012645:Selenomethionine / Q000032:analysis; D020942:Shiitake Mushrooms / Q000737:chemistry* / Q000254:growth & development; D018038:Sodium Selenite / Q000032:analysis; D014675:Vegetables / Q000737:chemistry* / Q000254:growth & development
chemical_list: D005308:Fertilizers; D018036:Selenium Compounds; D012645:Selenomethionine; D010447:Peptide Hydrolases; D012643:Selenium; D018038:Sodium Selenite; D064586:Selenic Acid