Effects of Maillard reaction products oil the oxidative cleavage and polymerization of protein under ascorbic acid-transition metal system

This study investigated the effects of Maillard reaction products (MRPs) on the oxidative cleavage and polymerization of BSA (bovine serum albumin) in an aqueous system. In L-ascorbic acid (AsA) and Cu(II) or Fe(III) reaction system, 50-60% of BSA was cleaved under physiological conditions (37 degre es C, pH 7.2), The oxidative cleavage induced by AsA-Cu(II) system was supp ressed to the extent of 32-86 % by model melanoidins or brown pigments from amino acids and foodstuffs, In the AsA-Fe(III) system, the oxidative cleav age was inhibited to the extent of 45-93% by melanoidins and brown pigments . However, this cleavage was promoted by amino acid Amadori rearrangement p roducts and brown pigment from soy paste. Therefore, MRPs show both suppres sion and promotion activity on oxidative cleavage of BSA in the system of A sA and a transition metal. The quantity of Amadori rearrangement moiety (AR M) in melanoidins from Lysine and brown pigments molecules from foods was a lso measured. From these data, it was estimated that the suppression and/or promotion of oxidative cleavage of BSA did not only depend on the quantity of ARM, but also depended on the chemical structure of ARM in melanoidins or brown pigments.