Complexation induced changes of rheological properties of starch systems at different moisture levels
Béatrice Conde‐Petit, Felix Escher
Journal of Rheology
Abstract
Starch, especially the linear amylose fraction, is able to form helical inclusion compounds or complexes with molecules like flavor compounds, fatty acids, and emulsifiers. The effects of starch complexation on rheological properties were studied (a) in aqueous dispersions of 1%–4% starch content, (b) in high-concentration gels of 40% starch content, and (c) in extrusion cooked low moisture starch blends. Complexation was followed by iodine binding capacity of starch and by differential scanning calorimetry. Rheological characterization was based on dynamic and steady shear measurements and on uniaxial force deformation tests. At low starch concentrations, the addition of complexing emulsifiers and flavor compounds induced gelation, provided that enough amylose was solubilized and swollen granules were present. Likewise, freshly prepared high-concentration starch gels with the addition of complexing ligands exhibited higher moduli of deformability than control samples without additives. The sequence of moduli of elasticity became inverse during storage as complexation lowered the rate of amylose retrogradation. Melt viscosity during cooking extrusion increased with the addition of both complexing emulsifiers and noncomplexing triglycerides, while paste viscosity of ground extrudates increased with emulsifiers but not with triglycerides. Influence of starch complexation seems to be parallel for all moisture levels indicating that the main feature is the formation of insoluble amylose complexes which in turn lead to the formation of a firmer network between the dispersed starch granules.
Extracted Claims
6 claims extracted from this paper into the knowledge graph
starch complexation induces gelation in aqueous dispersions
“At low starch concentrations, the addition of complexing emulsifiers and flavor compounds induced gelation, provided that enough amylose was solubilized and swollen granules were present.”
starch complexation increases paste viscosity of ground extrudates with addition of emulsifiers
“paste viscosity of ground extrudates increased with emulsifiers but not with triglycerides.”
starch complexation increases moduli of deformability in high-concentration starch gels
“freshly prepared high-concentration starch gels with the addition of complexing ligands exhibited higher moduli of deformability than control samples without additives.”