Thermogravimetry- and differential scanning calorimetry-based studies of the solid state reactions of starch polysaccharides with proteogenic amino acids

Waxy maize starch (NWS), pasted waxy maize starch (PNWS), amylopectin (AP), and amylose (A) produced dextrins when reacted thermally with proteogenic amino acids. The course of reactions depended on amino acid used. Analysis of diagrams of differential scanning calorimetry (DSC) and thermogravimetry (TG) suggests that all amino acids hut ARG and SER reacted with polysaccharides in the point of glassy transition of polysaccharide. Both ARG and SER first decomposed and their decomposition products reacted with polysaccharide, also in the point of polysaccharide glassy transition. Products of reaction of amylose with amino acids are more thermally stable than products from reaction of these acids with amylopectin. Free radicals produced from ail amino acids but these from ARG and TRP were C and O free radicals. ARG and TRP produced N free radicals. However, in combination with polysaccharides both these acids, similarly as all other amino acids, produced exclusively C and O free radicals. (C) 2001 Elsevier Science B.V. AH rights reserved.