Abstract

Corn starch has been widely used in biomaterial industry as one of the raw materials. The properties of starch such as annealing and the different ratio of amylose and amylopectin in different starch limit its application in production. These properties play a vital role in establishing relationships between other starches in structures and functions. Normal corn starches were treated with isoamylase for different hours and the gelatinization phenomena was observed with differential scanning calorimetry (DSC). The parameters of fracturability, cohesiveness, springiness and adhesive force were all detected by textural profiles analysis. After treatment with isoamylase, the content of amylose chains was increased, hardness and springiness of starch were all enhanced, while cohesiveness and adhesive presented an opposite trend. It was the different ratio of amylose and amylopectin that led to changes in physicochemical properties.

Key words: Corn starch, crystal structure, thermal properties, textural properties.

Abbreviation

DSC, Differential scanning calorimeter; T_o, melting temperature;T_p, peak temperature; T_c, conclusion temperature; ΔH_g, gel enthalpy.