Electrohydrodynamic drying (EHD) of wheat and its effect on wheat protein conformation

Abstract

This study investigates the electrohydrodynamic drying characteristics of wheat and its effect on the conformation of wheat protein using Fourier Transform Infrared Spectroscopy (FT-IR). A single wire electrode EHD system was used with a set electrode gap of 1.5 cm, applied voltages of 10 kV, 12.5 kV and 15 kV in combination with air cross-flow of velocities 1 m/s, 1.5 m/s and 2 m/s. It was observed that the drying rate of wheat sample was significantly affected by applied voltage and air velocity. The drying rate increased with an increase in air velocity and applied voltage. This study also showed that wheat protein conformation was significantly affected by EHD drying. In the analysis of the Amide I region (1720–1580 cm−1) of wheat protein, FT-IR spectra showed distinct valleys at 1682–1686 cm−1 (β-sheets), 1674 cm−1 (β-sheets), 1664–1667 cm−1 (turns), 1654–1657 cm−1 (α-helices), 1651 cm−1 (α-helices), 1645–1647 cm−1 (Random coils) and 1633–1634 cm−1 (β-sheets). Peak fitting using Gaussian band shapes suggested that exposure to electric field influenced the hydrogen bonding pattern of wheat protein resulting in shifts between low and high frequency bands which further supported these results.