Ultrasonication-induced structural and functional modification of starch in wheat flour

Abstract

This study investigated the effects of ultrasonication on the pasting, morphological, thermal, and rheological properties of wheat flour and dough, highlighting its potential as a green and sustainable processing technology. Wheat flour was treated with ultrasonic energy levels ranging from 40 to 140 kJ for 20 min. Rapid visco analysis (RVA) showed that at 40 kJ, peak viscosity increased from 1045.67 mPa·s (control) to 1259.00 mPa·s, and final viscosity rose from 2011.33 mPa·s to 2146.67 mPa·s, indicating enhanced gelatinisation. Differential scanning calorimetry revealed an increase in gelatinisation enthalpy (ΔH) from 8.03 J/g to 9.53 J/g, suggesting enhancement in molecular organisation. Rheological measurements demonstrated that ultrasonicated samples at 40 kJ and 100 kJ exhibited the lowest tan δ, suggesting improved elasticity and structural integrity. FTIR analysis confirmed intensified hydrogen bonding and improved gluten network formation. Low-field NMR and MRI analyses showed that ultrasonication significantly influenced water mobility and distribution within the dough. Moderate energy treatments (40 kJ to 100 kJ) enhanced water retention and network development. Scanning electron microscopy revealed surface roughness and partial granule disruption. These findings confirm that moderate ultrasonication enhances flour functionality by improving hydration, viscoelasticity, and thermal behaviour without the use of chemical additives. Ultrasonication offers an eco-friendly and energy-efficient approach for modifying wheat flour to improve the quality of sustainable flour-based products.

Keywords: Flow behaviour; Starch; Sustainable food processing; Thermal properties; Ultrasonication; Wheat flour.

Graphical abstract

Fig. 1

Morphological characteristics of control (untreated) and sonicated wheat flour, and dough in polarised light microscopy (PLM), scanning electron micrographs (SEM), and fluorescent scanning microscopy (FSM).

Fig. 2

Content of damaged starch of the control (untreated) and sonicated wheat flour. Data in figure are presented as mean ± standard deviation. Different lowercase letters indicate significant differences (p < 0.05), while the same lowercase letters indicate no significant difference.

Fig. 3

Pasting properties of the control (untreated) and sonicated wheat flour.

Fig. 4

(A) XRD pattern (The crystalline area “Ac” is represented by the orange baseline-marked region, while the amorphous area “Aa” corresponds to the region not covered by the orange baseline.), and (B) DSC curves of the control (untreated) and sonicated wheat flour. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 5

FTIR spectrum of the control (untreated) and (A) sonicated wheat flour, and (B) dough prepared by the sonicated wheat flour.

Fig. 6

Farinographic properties of the control (untreated) and dough prepared by the sonicated wheat flour in terms of (A) water absorption, (B) stability, and (C) peak time; Extensographic properties of the control (untreated) and dough prepared by the sonicated wheat flour in terms of (D) energy, (E) resistance to extension, and (F) extensibility.

Fig. 7

Dynamic viscoelasticity of the control (untreated) and dough prepared by the sonicated wheat flour in terms of (A) storage modulus (G′), (B) loss modulus (G′′), and (C) loss factor (tan δ).

Fig. 7

Dynamic viscoelasticity of the control (untreated) and dough prepared by the sonicated wheat flour in terms of (A) storage modulus (G′), (B) loss modulus (G′′), and (C) loss factor (tan δ).

Fig. 8

The (A) LF‐NMR results, and (B) magnetic resonance imaging (MRI) of the control (untreated) and dough prepared by the sonicated wheat flour.

Fig. 9

Schematic diagram of the ultrasonication processing and influence mechanism of ultrasonication on wheat flour.