Effects of Cationic Species on Visual Color Formation in Model Maillard Reactions of Pentose Sugars and Amino Acids

摘要

Effects of cationic species on Maillard browning were examined after heating (ca. 100 °C) aqueous pH 7.2 buffered solutions of amino acids and pentose sugars. Metallic ions of Group I metals (Li, Na, K, Rb and Cs) produced a small increase in browning (A_(420)), but somewhat greater effects were observed with ions of Group II metals Ca and Mg. Browning was suppressed by triethylammonium ion, but unaffected by a salt of the stronger base, guanidine. The quaternary amine salt choline chloride produced enhanced browning and served as a model for phospholipid involvement in Maillard reactions. With α,ω-diamino acids increases in browning were observed which related to lowered pK2 values resulting from positively charged ω-substituents in these molecules.