インスタントコーヒー中の鉄結合性物質の検索 (2)  [in Japanese] Identification of Iron-Binding Compound in Instant Coffee  [in Japanese]

Coffee inhibits nonheme iron absorption in humans. We screened compounds in instant coffee to find which compounds inhibits iron absorption. Binding of iron was checked by the formation of complexes of a compound with Fe (II), identified by high-pressure liquid chromatography with a GPC column equilibrated with 0.1 M FeS0_4 in 0.01 M acetate buffer (pH4). Iron-binding compounds were purified and isolated from instant coffee by ion-exchange chromatography, gel permeation chromatography, cellulose chromatography, and differences in solubility. 0ne such compound was identified as aspartic acid by spectral analysis (infrared absorption, nuclear magnetic resonance, and mass). The compound was an enantiomorphic mixture, which might be produced when coffee beans are roasted. Aspartic acid was about 0.4% of the instant coffee by dry weight.