title: The adsorption of volatile aroma constituents by foods. VIII. Adsorption of volatile carbonyl compounds by amino acids.
abstract: The adsorption of some volatile aldehydes and ketones by 22 dry amino-acids was studied. The adsorbed amounts decreased approximately in the order: propanal, biacetyl, hexenal, hexanal, acetone, pentan-3-one, nonan-3-one, undecanal and nonan-5-one, but there were great differences in the adsorption capacity of the amino acids. Lys adsorbed best and often irreversible, arg, his, phe, trp, pro, and val (leu, ile) very good. With cys, thiazolidinecarboxylic acids were formed. In most cases of adsorption exceeding 100 mmol/mol, except for the monoketones, strong discoloration, probably of the maillard type, was observed. Propanal and hexanal were to a great extend converted to aldol addition and condensation products. Tyr and hyp adsorbed less than the corresponding amino-acids without hydroxyl groups. This is attributed to stronger crystal-lattice forces.
mesh_terms: D000327:Adsorption; D000447:Aldehydes; D000596:Amino Acids; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005421:Flavoring Agents; D005502:Food; D007659:Ketones; D014835:Volatilization
chemical_list: D000447:Aldehydes; D000596:Amino Acids; D005421:Flavoring Agents; D007659:Ketones