Physicochemical and structural characteristics of the Venn components of wheat gliadin
Feng Jia, Changfu Zhang, Qi Wang, Jinhe Li, Yu Chen, Jinshui Wang
Grain & Oil Science and Technology
Journal Pre-proof J o u r n a l P r e -p r o o f 2 Abstract: The aim of this study was to analyze the physicochemical and structural characteristics of the Venn components of wheat gliadin to provide theoretical basis of gliadin for processing in dough and Chinese steamed bread. Eight Venn components, , were extracted from wheat gliadin based on their solubility. The results of physicochemical characteristics showed that the differences in the contents, TDS and electrical conductivity, particle
... size and zeta potential of Venn components were significant, respectively. The content of the Gli-15 in gliadin was the highest, and the content of the Gli-9 was the lowest. The TDS value of Gli-9 was the highest (336.0), and the TDS value of Gli-15 was the lowest (52.0). The electrical conductivity of Gli-9 was the highest, which was 7.54 times the lowest value of Gli-11. The zeta potential of Gli-9 was -25.2 mV, and the zeta potential of the Gli-15 was -7.64 mV. However, the difference in the pH values was not significant. The results of UV spectrum and FTIR analysis showed that the secondary structures of the Venn components had significant differences. The results of the XRD patterns indicated that the Venn components might not be a single substance. The results of CLSM images implied that the molecular interactions between the components were varied. Hence, the results could provide research materials and basic data for the deep processing and utilization of gliadin. The XRD patterns of Venn components of gliadin were presented in Fig. 4 . According to XRD patterns, several characteristic reflections were detected in the XRD patterns of Gli-10, which were superimposed on an amorphous background where at least a portion of the protein in Gli-10 existed in the crystalline state. In addition to the group Gli-10, the diffraction pattern of the Journal Pre-proof J o u r n a l P r e -p r o o f 9 other 7 Venn components showed one broad peak with characteristic distances of 20 ° (Fig 4) , which was characteristic of amorphous materials. Among them, the diffraction and absorption values of the waveforms from Gli-8 to Gli-15 were quite different, suggesting that there were great differences in the separated substances of the eight components. The results were similar to the one from Sharif et al.  , in which the diffraction patterns of the pure gliadin showed a broad diffraction band around 14 °. This research suggested that pure gliadin was amorphous because it displayed no Bragg reflections and only broad humps in its pattern   .