Debranching and Crystallization of Waxy Maize Starch in Relation to Enzyme Digestibility
Molecular and crystal structures as well as morphology during debranching and crystallization of waxy maize starch at a high solid content (25%, w/w) were investigated, and the results were related to the digestibility of debranched products. The starch was cooked at 115-120 C for 10 min, cooled to 50 C and debranched by isoamylase. After 1 h of debranching, wormlike objects with 5-10 nm width and ca. 30 nm length were observed by transmission electron microscopy. Further release of linear chains and crystallization led to assembly of semi-crystalline structures in the form of nano-particles and subsequent growth of nano-particles into large aggregates. After 24 h at 50 C, a debranched starch product with an A-type X-ray diffraction pattern, a high melting temperature (90-140 C), and high resistant starch content (71.4%) was obtained. Small-angle X-ray scattering results indicated that all debranched products were surface fractal in a dry state (4% moisture) but had a mass fractal structure when hydrated (e.g. 45% moisture).
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- DOE - OFFICE OF SCIENCE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1020226
- Report Number(s):
- BNL-96076-2011-JA; CAPOD8; TRN: US201116%%206
- Journal Information:
- Carbohydrate Polymers, Vol. 81, Issue 2; ISSN 0144-8617
- Country of Publication:
- United States
- Language:
- English
Similar Records
Linear starch and hexanoic acid complexation evaluated by isothermal titration calorimetry
Melt rheology and molecular weight degradation of amylopectin during multiple pass extrusion of starch
Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
AMYLASE
CHAINS
CRYSTAL STRUCTURE
CRYSTALLIZATION
ENZYMES
FRACTALS
ISOENZYMES
MAIZE
MELTING
MOISTURE
MORPHOLOGY
SCATTERING
STARCH
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
national synchrotron light source