To the problem of structure of D-maltose caramelization products in aqueous-ethanolic media

The research of caramelization processes in carbohydrate systems is traditionally complicated by rather rigid conditions of carrying out reactions resulting in the significant amount of products, at the same time the predicted caramels properties are biologically important, in this connection studying of the formation structure defining them is perspective. Based on the analysis of derivative IR-spectroscopy data reference of the main absorption bands in the either-linkage vibration region is made, presence of the glycoside fragments which are both maltose fragments in caramel structure and new oligomers forming via caramelization is shown. In is concluded based on the fact of registration of side absorption bands in intervals of 1200-1000 and 990-930 cm-1. Formation of oligoglycosides is implemented at thermal influence in rather weak conditions of a thermostatting in the mixed solvent and following activating effect of alkali. Mechanisms of intermediate products formation at incipient states can be presented as alkaline solvolysis of maltose, or recyclization with elimination and formation of dicarbonyl reductons; formation capable to further thermal conversions anhydroforms is in case of the former probable, the second pathway is a key one for formation of colored caramelization products. Amount of the initial non-selective processes leads to formation at late stages the products mixture capable to fractionating by dialysis. The analysis of IR spectrums in carbonyl area shows existence in the complete reaction systems products of absorption bands, assigned to β-dicarbonyl and the conjugated β-hydroxy-α,β-enone fragments (1600, 1625, 1720 cm-1), which are not fixed in IR-spectrums of nondialyzable products. On this basis it is possible to refer the considerable proportion of the colored products to low-molecular structures, whereas the IR-spectrum of nondialyzable product rather "poor" in bands represents an oligomeric component of caramels.