title: Mass spectrometric evidence for a zinc-porphyrin complex as the red pigment in dry-cured Iberian and Parma ham.
abstract: Extracts containing red pigment complexes from the two types of dry-cured hams, Italian Parma and Spanish Iberian ham, were obtained using water and acetone as extraction solvents followed by a crude purification with C18 column filtration. The purified extracts were then analyzed spectroscopically by recording absorption and fluorescence spectra (λ(ex)=420nm), which both indicate the presence of chemically identical red chromophores with properties similar to a complex of transition metals and protoporphyrin IX. Electrospray ionization mass spectrometry (ESI-MS) in the positive ion mode confirms the presence of identical chemical compounds. ESI-MS in the negative ion mode detects a cluster of seven isotopologue ions (that of m/z 623.2 as the most intense) with a pattern matching that of a Zn protoporphyrin IX complex. Based on mass spectral data it is concluded that a Zn-porphyrin complex constitutes a major chromophore in dry-cured Iberian ham as well as in Parma ham.
authors: Royal Veterinary and Agricultural University, Department of Food Science, Food Chemistry, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors: Jens K S
authors: JK
authors: Møller
authors: Christina E
authors: CE
authors: Adamsen
authors: Rodrigo R
authors: RR
authors: Catharino
authors: Leif H
authors: LH
authors: Skibsted
authors: Marcos N
authors: MN
authors: Eberlin