Thermal degradation and stability of starch under different processing conditions

Abstract

The objectives of this paper are to review the thermal degradation and stability of starch and starch‐based materials, including both fundamental sciences such as detecting techniques, the effect of amylose/amylopectin content in starches and starches modifications, as well as the effect of different processing environments, such as an open or sealed system, and shearless or shear stress conditions. The decomposition temperature of starches was increased with increasing amylopectin content in an open system. In the open system, the initial water content did not affect the decomposition temperature because all water had evaporated from samples prior to reaching the decomposition temperature. Two decomposition temperatures were observed in the sealed system: the first at lower temperature represents long chain scission; and the second at higher temperature involves decomposition of glucose ring. In the sealed system, the first degradation was increased with increasing amylopectin content. There is no observable difference of the second degradation for the samples containing different amylose/amylopectin ratios. The higher the moisture content is, the lower the second decomposition temperature is detected in the sealed system. Significant shear degradation was observed in amylopectin component of starch, while high amylose starch proved less sensitive to shear stress. The achievements in this area have increased the knowledge of polymer science, in particular to understand the degradation of natural polymers.

Starch-g-poly(benzyl methacrylate) copolymers

“…The type of the emitted gaseous decomposition products indicates mainly on the breaking of the glycosidic bonds, strong bonds and thermal dehydration of starch from studied copolymers under the first decomposition stage. Those observations are in accordance with the results obtained by other researches [28,40,[44][45][46][47][48].…”

Effect of extrusion treatment on the thermal stability and structure of corn starch with different emulsifiers

“…The results showed that the starch extrudate particles were found to be more thermally stable than native corn starch. The emulsifier was a coupling agent that improved the compatibility between the hydroxyl of starch and the ester bond of emulsifiers and then the thermal stability of starch extrudate particles improved (Liu et al 2013;Tupa et al 2015). The results clearly illustrated that the emulsifier significantly enhanced the thermal stability during extrusion processing.…”

Characterization of cassava starch processed in an internal mixer

“…Low SME at high moisture content (Figure 2) could be explained by the decrease of shearing, attributed to the lubricating effect of water by reducing the total molecular weight in the mixer, whereas an increase of SME with increase of rpm is due to the molecular friction caused by the simultaneous increase in shear rate [18] . and 70.0 °C, respectively.…”