SEPARATION OF THE COLORED REACTION-PRODUCTS FORMED IN BETA-CAROTENE AND OR PHENYLALANINE MODEL SYSTEMS

Model systems comprising beta-carotene or phenylalanine or beta-carotene and phenylalanine in liquid paraffin were heated at 210-degrees-C for 15 min. The absorbance of the mixture (at 420 nm) was about 15 and 20 times those obtained for the phenylalanine and beta-carotene systems, respectively. The methanol extractable components (MEC) of each system represented 17.6, 76.4 and 14.0%, respectively, of the coloured components present after heating (based on absorbance at 420 nm). HPLC of beta-carotene MEC revealed no major peaks when monitoring at 420 nm, while TLC gave only one coloured band. In contrast, HPLC chromatograms for the mixture and the phenylalanine systems were complex, and, based on HPLC diode array data, four major peaks were common to both, with two being present in significantly larger amounts in the phenylalanine system. Subsequent HPLC analysis of the TLC bands permitted the detection of further components.