Study of cryostructuration of polymer systems. XVIII. Freeze-thaw influence on water-solubilized artificial mixtures of amylopectin and amylose

Abstract

The effects caused by cryogenic treatment (freezing–frozen storage–thawing) of 0.5–2.0 g/dL solutions of individual starch polysaccharides, namely, amylopectin (solvents: water or 0.35M NaCl aqueous solution) and amylose (solvent: 0.35M NaCl aqueous solution), and also of 0.5 g/dL solutions of their artificial mixtures with various amylopectin/amylose ratios were studied. Freezing of these systems at temperatures from −6 to −24°C for 18 h and subsequent thawing resulted in the formation of cryogelled or cryoprecipitated matter whose morphology and yield depended on the type of polysaccharide, initial polymer concentration, portion of each macromolecular component in the mixed systems, and conditions of cryogenic treatment. Comparison of the process efficiency in the mixed systems during the formation of precipitates (from storage at room temperature) and cryoprecipitates (as a result of cryogenic treatment) revealed the promoting effects of the freezing–thawing influence on polymer–polymer association and showed the presence of some synergism in the mutual interaction of these polysaccharides. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 371–381, 2000