Sugar-amine fluorophore, chemical

Possible Chemical Nature of the Sugar-amine Fluorophore In sugar-amine browning, the relative amount of the fluorophore is usually low. Adhikari and Tappel found 130 pmoles per mole of glucose based on an assumption of an amino-imino-propene moiety (11). The relative amount of acid reducing power is usually much higher (28). But of course it cannot be assumed, no matter how simple the system, that the polymer-bound fluorophore and reducing power reside in the same molecule. 

Similarities in the spectrofluorometric and chemical behavior of the malonaldehyde and Maillard adducts and the constraints of the rather precise geometry of the available amine groups in microcrystalline polyamide are consistent with a possible carbohydrate-substituted amino-iminopropene derivative for the sugar-amine fluorophore. The malonaldehyde product with amino acids and amines has been demonstrated by others to have an amino-iminopropene moiety. 

Carbohydrates show very low ultraviolet (UV) absorption. Their visualization and evaluation on TLC plates can be satisfactorily made only after suitable derivatization. The majority of chemical derivatization procedures are based on the reductive properties of carbohydrates. Reductive amination of sugars in the presence of an acid is a typical example. Methods based on reductive amination require an aldehydic reducing carbon on the saccharide that reacts with the amino group of the chromophore or fluorophore. 

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