Mechnism study of different pasting properties among wheat starch in different damage levels

• 1、School of Food Science and Technology,Jiangnan University,Wuxi 214122

Abstract：In this study, the pasting properties, dissolution behavior, molecular structure of starch and soluble starch in various damaged starch levels were investigated. The damaged starch was obtained by different ball-milling time. The results showed that, compared to amylose (AM), the dissolution rate of amylopectin (AP) increased with the enhanced level of damaged starch. The AM-AP ratio of soluble starch was significantly positively correlated (p < 0.05) with RVA peak viscosity, trough viscosity, final viscosity and breakdown respectively. Disruption of crystalline structure of starch and minor molecular degradation of AP were induced by mechanical damage. Differences of RVA viscosity could be corrected by altering mechanical stirring speed. Mechanism of pasting properties differences among wheat starch of different degrees of damage was concluded as follows: Mechanical damage led to a more disrupted crystalline structure together with the increasing surface area and more loosely structure, therefore, AP was easier to dissolute, which had weakened the rigidity of the residue starch and decreased the viscosity of starch system.

Keywords： food science damaged starch pasting properties dissolution behavior molecular structure