Amino-reductone reaction products

Omura, H. Inoue, Y. Eto, M. Tsen, Y.-K. Shinohara, K. Reaction products of triose reductone with some amino acids. Kyushu Daigaku Nogakubu Gakugei Zasshi 1974, 29, 61-70. 

Its formation from rhamnose heated with piperidine acetate in ethanol, under the same conditions that produced amino-hexose-reductones from glucose and other hexoses, was described as early as 1963 by Hodge et al., who confirmed the structure by IR and NMR data and proposed a formation pathway. The formation from Amadori intermediates was been reviewed by Vernin (1981). Numerous model systems have confirmed that it is one of the main Maillard-reaction products. For instance we will mention the formation from L-rhamnose and ethylamine (Kato et al., 1972) and from pentose/glycine or alanine, whose mechanism was proposed by Blank and Fay (1996) and Blank et al. (1998), from the intermediate Amadori compound, /V-(l-deoxy-D-pentos-l-yl)glycine. Furaneol is also formed by recombination of... 

The chemistry of the browning reaction has been reviewed periodically (1-7). The carbohydrate-amino acid browning reaction produces literally hundreds of reaction products. Despite the fact that the Maillard reaction has been investigated for many years, we cannot as yet identify all the reactant compounds. The first steps are, however, clearly established. The aldose or ketose reacts with amine to produce N-substituted glycosyl amine (Fig. 1). This rearranges, as illustrated, to produce a 1-amino-desoxy-2-ketosyl amine. If it is blocked, the overall reaction is blocked. This key compound or compounds can then continue to react (Fig. 2). The desoxy-ketose or amadori rearrangement product can dehydrate to produce furfural-like compounds or, through the loss of water, produce reductones. All of these compounds can react with one another or with other amine compounds to produce a wide variety of reaction products. 

The most practical method for preventing WOF in meat products is to add antioxidants prepared from natural precursors such as sugars and amino adds by heating them to produce constituents that not only act as antioxidants but serve to enhance meaty flavor as well. The resulting Maillard products have been known to have antioxidant activity in lipid systems (6-8). It is assumed that the antioxidative property of the Maillard reaction is assodated with the formation of low molecular weight reductones and high molecular weight melanoidins (6, 7, 9-13). 

Knowledge about the chemical structure of the antioxidative MRP is very limited. Only a few attempts have been made to characterize them. Evans, et al. (12) demonstrated that pure reductones produced by the reaction between hexoses and secondary amines were effective in inhibiting oxidation of vegetable oils. The importance of reductones formed from amino acids and reducing sugars is, however, still obscure. Eichner (6) suggested that reductone-like compounds, 1,2-enaminols, formed from Amadori rearrangement products could be responsible for the antioxidative effect of MRP. The mechanism was claimed to involve inactivation of lipid hydroperoxides. 

The chemical degradation of carbohydrates, particularly under acidic conditions, produces reductones, furan derivatives, pyruvaldehyde, and so on, which can condense, either among themselves or with amino compounds (Maillard reactions), to produce dark-colored, amorphous products, similar to humic substances. Pyruvaldehyde, which has been held to be an intermediate in Maillard reactions, has been identified in many soils. Such con-... 

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