title: Yolk of the Century Egg (Pidan) Contains a Readily Digestible Form of Free Vitamin B12.
abstract: In this study, we determined the vitamin B12content of commercially available century eggs (pidan) and characterized their vitamin B12compositions in detail. The egg yolk and white of century eggs (each 100 g wet weight) contained 1.9±0.6 and 0.8±0.3 μg of vitamin B12, respectively. The vitamin B12compounds purified from the egg yolk and white were identified as vitamin B12using liquid chromatography-electrospray ionization/tandem mass spectrometry. The vitamin B12present in the yolk or white of century eggs was recovered completely in macromolecular fractions, but not in free vitamin B12fractions by Sephadex G-50 gel filtration. However, with respect to the vitamin B12bound to protein in the century egg yolk, approximately 52% of the free vitamin B12was formed during in vitro gastric digestion and no free vitamin B12was detected in the egg white.
authors.affiliation: Division of Applied Bioresources Chemistry, The United Graduate School of Agricultural Sciences, Tottori University.
authors.forename: Fei
authors.initials: F
authors.lastname: Teng
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Bito
authors.forename: Shigeo
authors.initials: S
authors.lastname: Takenaka
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Yabuta
authors.forename: Fumio
authors.initials: F
authors.lastname: Watanabe
mesh_terms: D002853:Chromatography, Liquid; D004063:Digestion; D004529:Egg White / Q000737:chemistry*; D004530:Egg Yolk / Q000737:chemistry*; D005504:Food Analysis; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D053719:Tandem Mass Spectrometry; D014805:Vitamin B 12 / Q000032:analysis*
chemical_list: D014805:Vitamin B 12