Structure, thermal stability and suspension rheological properties of alcoholic-alkaline-treated waxy rice starch.

Structure, thermal stability and suspension rheological properties of alcoholic-alkaline-treated waxy rice starch. Int J Biol Macromol. 2019 May 04;: Authors: Chen F, Xie F, Liu P, Chen P Abstract In this work, the effect of alcoholic-alkaline treatment on the characteristics of waxy rice starch (WRS) and its aqueous suspensions was studied for the first time. Microscopy shows that the alcoholic-alkaline-treated WRS (AAT-WRS) was in the form of particles of lengths between 10 and 50 μm. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses indicate that the original A-type crystallites of WRS had been completely eliminated by the alcoholic-alkaline treatment and no new crystalline structure was formed. Fourier-transform infrared (FTIR) spectroscopy confirms the absence of chemical reactions during the treatment. Thermogravimetric analysis (TGA) results indicated the decreased thermal stability of AAT-WRS, which may be attributed to the amorphous structure and possible degradation resulting from the treatment. Compared with the gelatinized starch suspension, the AAT-WRS aqueous suspension presented a weaker shear-thinning behaviour, lower steady-shear viscosity, lower storage and loss moduli, and higher loss tangent, which suggest a less-rigid gel structure. The rigidity of the gel further decreased with higher temperatures. Our results here could provide insights into the rational design of modified starch p...
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Tags: Int J Biol Macromol Source Type: research