title: Content and characteristics of vitamin B12 in some seaweeds.
abstract: The vitamin B12 (B12) content in seven species of seaweed that are consumed frequently in Hokkaido, Japan, was microbiologically measured using Escherichia coli 215. Asakusanori (Porphyra tenera), maruba-amanori (Porphyra suborbiculata) and akaba-gin-nansou (rhodo-glossum pulcherum) showed higher B12 content than the other species, although the content varied greatly among samples in the same species. A bioautography on a thin-layer plate holding a mixture of silica gel and cellulose, differentiation of B12 and its analogues using a binding specificity of intrinsic factor and haptocorrin, and comparison of the B12 concentration determined by the radioisotope dilution assay method using the intrinsic factor as the B12-binding protein with that by the bioassay method, predominantly showed B12 in maruba-amanori and B12 analogues in wakame (Undaria pinnatifida) and akaba-gin-nansou. The B12 uptake of akaba-gin-nansou from artificial seawater was similar to that of asakusanori that contained only B12.
authors.affiliation: Department of Home Economics, Faculty of Education, Hokkaido University of Education, Sapporo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Shibata
authors.forename: M
authors.initials: M
authors.lastname: Takayama
authors.forename: Y
authors.initials: Y
authors.lastname: Narita
authors.forename: K
authors.initials: K
authors.lastname: Sugawara
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
mesh_terms: D002855:Chromatography, Thin Layer; D012624:Seaweed / Q000737:chemistry*; D013045:Species Specificity; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D014805:Vitamin B 12