Formation Mechanism of the Free Radical Product and Its Precursor by the Reaction of Dehydro-L-ascorbic Acid with Amino Acid

Red pigment formation by the reaction of oxidized ascorbic acid and protein in a food model system of low moisture content.

“…The values obtained are expressed as % of the value for the residual free amino group in the unreacted food model mixture. 6. Amino acid mixture.…”

Purple Pigment Produced by the Reaction of Dehydro-L-ascorbic Acid with Phenylalanine

“…It is therefore certain that the oxidizing condition in the starting DHA-Phe mixture shifts grandually to a reducing condition, along with formation of some reducing products such as ascorbic acid. 9 ) The stability of the purple pigment was preliminarily examined by measuring the decrease of O.D. of its aqueous solution at 570 nm at pH 7.0 at room temperature.…”

Red Pigment Formation by the Reaction of Oxidized Ascorbic Acid and Protein in a Food Model System of Low Moisture Content

“…1) In a series of works on the reaction of dehydroascorbic acid (DHA) with amino acids, we have found the formation of three novel free radical products and have been able to. establish the .complete reaction processes in that system involving radical formation and browning.2 "-' 6) It had been surmised that reactions involving a-amino acid were of rather less importance to food systems than those involving proteins. However, little was known about the reaction of protein with DHA, despite many investigations on Maillard reactions of protein with reducing .sugar that resulted.…”