title: Characterization of vitamin B12 compounds from Korean purple laver (Porphyra sp.) products.
abstract: Vitamin B(12) contents of various Korean purple laver products were determined with the microbiological vitamin B(12) assay method. Although a substantial amount (133.8 microg/100 g) of vitamin B(12) was found in dried purple laver, seasoned and toasted laver products contained lesser vitamin B(12) contents (about 51.7 microg/100 g). The decreased vitamin B(12) contents in the seasoned and toasted laver products, however, were not due to loss or destruction of vitamin B(12) during the toasting process. Silica gel 60 thin layer chromatography-bioautogram analysis indicated that all Korean laver products tested contain true vitamin B(12), but not inactive corrinoid compounds. In vitro gastrointestinal digestion experiments indicated that digestion rate of vitamin B(12) from the dried Korean purple laver was estimated to be 50% under pH 2.0 conditions (as a model of normal gastric function). These results suggest that Korean purple laver products would be excellent vitamin B(12) sources for humans, especially vegetarians.
authors.affiliation: Department of Health and Nutrition, Nagasaki International University, Sasebo 859-3298, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Miyamoto
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Yabuta
authors.forename: Chung Shil
authors.initials: CS
authors.lastname: Kwak
authors.forename: Toshiki
authors.initials: T
authors.lastname: Enomoto
authors.forename: Fumio
authors.initials: F
authors.lastname: Watanabe
mesh_terms: D001682:Biological Availability; D002855:Chromatography, Thin Layer; D003890:Desiccation; D004063:Digestion; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D066298:In Vitro Techniques; D007723:Korea; D010434:Pepsin A / Q000378:metabolism; D044664:Porphyra / Q000737:chemistry*; D014805:Vitamin B 12 / Q000032:analysis* / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D010434:Pepsin A; D014805:Vitamin B 12