Properties and Structure of Amylose‐Glyceryl Monostearate Complexes Formed in Solution or on Extrusion of Wheat Flour

Abstract
Differential scanning calorimetry (DSC), alpha‐amylolysis, and gel filtration chromatography (GFC) were used to characterize the lamellar morphology of solution‐grown amyloseglyceryl monostearate (GMS) complexes. The complexes grown at 60°C and 90°C had melting temperatures of 100°C and 114°C, respectively. Both enzyme digested complexes had broad overlapping GFC chromatographs; however, the amylose‐GMS‐90°C complex had chain lengths 25% to 40% larger than the lower temperature complex. Assuming the main GFC peak was representative of the ordered lamellar regions, the complexes grown at 60°C and 90°C had helical chain segments of 104 Å and 145 Å, respectively. The influence of GMS addition on the twin screw extrusion of soft wheat flour was also investigated. Formation of a complex during extrusion, characteristic of the amylose‐GMS‐90°C polymorph, decreased the starch solubility, water holding capacity, enzyme susceptibility and degree of expansive‐puffing of the extrudate.