Non‐volatile Reaction Products by Heat‐induced Degradation of α‐Glucans. Part I: Analysis of Oligomeric Maltodextrins and Anhydrosugars

Abstract

Abstract The non‐volatile reaction products of the thermolysis of maltodextrines and soluble starch in a closed system at 180°C are analysed and are compared with those of the thermolysis of D‐glucose and 1,6‐anhydro‐β‐D‐glucose. Without derivatization the methods of AMD/HPTLC and HPAEC/PAD are suitable for the quantitative determination of mono‐ and oligomeric saccharides. On the reaction conditions used the thermolysis/hydrothermolysis of polymeric α‐glucanes first leads to the formation of D‐glucose and predominant to 1,4‐linked maltooligosaccharides. These intermediates undergo further reactions such as hydrothermolysis, transglycosylation, dehydration, and isomerisation. As a result of these reactions non‐volatile degradation products with sugar structure such as monomeric sugars (D‐glucose), anhydrosaccharides, fructose containing sugars and short chain, partly branched, maltodextrines are formed. These reaction products can act as starting material for non‐enzymatic browning reactions and produce either typical caramelisation products, connected with changes of the sugar structure, or Maillard ‐reaction products in the presence of amino compounds.