Effect of Sucrose Esters on the Physicochemical Properties of Wheat Starch
Purpose: To investigate the effect of sucrose esters on the physicochemical properties of wheat starch.
Methods: Sucrose ester was mixed with wheat starch extracted from normal soft wheat cultivars and heated. Change in starch properties arising from the interaction between were assessed for starch blue value, viscosity, solubility and retrogradation. In addition, the structure and thermodynamic properties of the modified starch were analyzed by Fourier transform infrared spectroscopy (FITR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).
Results: The properties of wheat starch changed greatly by adding different sucrose esters to their structures. Starch containing 0.30 % sucrose esters had the lowest peak (2034 cps), trough (1331 cps), final (1896 cps), setback viscosities (565 cps), iodine value (0.378), supernatant volume (76.6mL), and lower dissolution rate (0.063g). The unmodified starch had higher peak (3576 cps), trough (2971 cps), final (4394 cps), setback viscosities (1423 cps), blue value (0.464), supernatant volume (85.4 mL ), and dissolution rate ( 0.076 g). After adding sucrose esters, the onset temperature (To) and peak temperature (Tp) of wheat starches increased by 1 - 5 °C and 1 - 3 °C, respectively; the conclusion temperature (Tc) and enthalpy, however, decreased by 5 - 6°C and 0.2 - 1.9 J/g, respectively. SEM and FT-IR showed that the microstructure and molecular structure of the starches with sucrose esters did not differ significantly from that of the unmodified starch.
Conclusion: Incorporation of small amounts of sucrose ester in the structure of wheat starch can change the physicochemical properties of the starch to meet various functional requirements, including in the food and pharmaceutical industries.
Keywords: Sucrose esters, Wheat starch, Viscosity, Microscopy; Microstructure, Differential scanning calorimetry, Fourier transform infrared spectroscopy.