Dielectric Properties of Hydrothermally Modified Potato, Corn, and Rice Starch

Abstract

The effect of starch granule sizes, shapes, composition, and frequency on the dielectric properties (dielectric constant, loss factor, and conductivity) of native and hydrothermally modified starches (potato, corn, and rice starch) are investigated in this work. Dielectric properties are determined from 5 Hz to 5 GHz. The modified starches exhibit lower dielectric properties than the native starches from 5 Hz to 5 GHz due to the disruption of the native polysaccharide’s molecular arrangement. The modified potato starch shows the highest loss factor (208.12 at 50 Hz and 19.95 at 500 Hz) and stable conductivity (~5.33 × 10−7 S/m at 50 Hz and 500 Hz) due to the larger continuous network structure after hydrothermal modification. The rice starch shows the largest difference in dielectric constant (47.30%) and loss factor (71.42%) between the modified form and native form in the frequency range of 5 MHz–5 GHz. This is due to the restriction of dipole motions in the closely packed structure after hydrothermal modification. The findings indicate that the quality of starch modification can be characterized by dielectric properties for assisting starch-based plastic production’s design.

Dielectric properties of raw Aster tataricus and its residue of decoction

“…This decrement with a low gradient can be noticed at high frequencies for both raw AT and residue. This might be ascribed to the dipoles that are unable to fully polarize with respect to the oscillating polarity of the applied field [23].…”

“…It can be observed that ε′ and ε″ are nonlinear with respect to the frequency at a constant temperature. This decrease is mild at high frequencies for both AT pellets as shown in Figure-1 and Figure-2.This might be mainly ascribed to the space charges of the samples having insufficient time to realign with the oscillation of the applied electric field[23]. It implies that the polarization mechanism is switched from low to high frequency.…”

The Photoprotective Protein PsbS from Green Microalga Lobosphaera incisa: The Amino Acid Sequence, 3D Structure and Probable pH-Sensitive Residues

“…For the inner region of the membrane formed by fatty acid residues, we used ε s = 2.0 in most of the experiments and ε s = 2.5 while assessing the probable error resulting from variations in this parameter. For the outer regions containing hydrophilic heads, we used the experimental data obtained for glycerol [33] and starch [55]. The former gave ε s ≈ 40.0, and the latter gave the range ε s ≈ 26-70 for different forms of starch.…”

The Simulation of Dielectric Barrier Discharge for Breakdown Voltage in Starch Modification

“…Starch is widely utilized in the food and non-food industries, as well as in the production of biodegradable packaging and in the chemical, pharmaceutical, and biomedical fields [4][5][6]. Starch is treated with various physical, chemical, and biological/enzymatic processes to modify its structure and provide it with functional properties needed for particular usages [7][8][9]. The limitations of starch's original form prevent its employment in a variety of applications.…”