Although flaxseed gum (FG) has been widely studied, the differences in its structure and function with respect to various flaxseed cultivars remain unclear. In this study, our objective was to examine the differences between FG samples obtained from different flaxseed cultivars based on their structural and functional properties. Specifically, FG samples from the different cultivars were extracted via hot water extraction followed by ethanol precipitation. Thereafter, they were analyzed via zeta potential measurements, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The results demonstrated that the different cultivars showed significantly different FG yields (p < .05; range, 5.83%-7.36%). Further, the FTIR spectra of the FG samples were slightly different but showed typical polysaccharide absorption peaks. Furthermore, the XRD patterns obtained predominantly showed an amorphous region and a small crystalline region, while the SEM images obtained at 1,000× magnification revealed that the samples had smooth and irregular surfaces, with a scaly structure. However, at 20,000× magnification, the FG samples showed slight structural differences. Additionally, the zeta potentials of the FG samples (range, -19.4 to -30.6 mV; p < .05) were cultivar-dependent and indicated the presence of negatively charged macromolecules. This implies that the FG samples from the different cultivars show diverse structural properties. Our findings not only provide useful information regarding FG samples extracted from different cultivars but also serve as a theoretical basis for the application of FG in food processing.
Keywords: Fourier‐transform infrared spectroscopy; X‐ray diffraction; flaxseed cultivar; flaxseed gum; scanning electron microscopy; zeta potential.
© 2021 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.