抄録
The nondialyzable melanoidin prepared from glucose-ammonia system (kept in pH 5.3_??_6.0 during the reaction) was hydrolyzed. The hydrolyzate was fractionated by DEAE-cellulose column and Dowex 50 W column. Deoxyfructosazine and its 6-isomer were respectively isolated from main two fractions, and identified. Even on boiling the melanoidin in aqueous solution, these pyrazines as well as imidazoles1) and β-hydroxy pyridines1) in the melanoidin were liberated.
Furthermore, amounts of these heterocyclic compounds liberated from the nondialyzable melanoidin and the fractionated melanoidins (fractionated into five fractions on DEAE-cellulose column according to the method described previously2)) were examined.
The results obtained seem to suggest that these heterocyclic compounds are not present probably as a molecular skelton or an inclusion compound in the melanoidin, but as a small moiety of the melanoidin molecule with loose chemical bond.
