Confirmation of Monascus Pigment Colored on the Skin of Fresh Fishes

Abstract

A method for the confirmation of monascus pigment colored on the skin of fresh fishes was developed. A fish sample was extracted once with methanol at room temperature (30min), and the extract or its condensate was checked for monascus pigment by visible absorption spectrometry, green fluorescence after reaction with ammonia and acetone, and thin layer chromatography. The extract which seemed to contain monascus pigment was further examined by liquid chromatography and gas chromatography-mass spectrometry (GC-MS). On the liquid chromatogram using two eluants successively, monascus pigment showed a characteristic peak to both visible and fluorescent detection, which, was a clear indication of monascus pigment. Complex peaks appeared on the GC-MS total ion chromatogram, but the constituents of monascus pigment were identified by the mass spectra of these peaks, which could be used to confirm monascus pigment. © 1988, The Pharmaceutical Society of Japan. All rights reserved.