Combined effects of quercetin and sodium chloride concentrations on wheat gliadin structure and physicochemical properties

Abstract

BACKGROUND Polyphenols may interact with protein via covalent bonds and non‐covalent interactions, improving the structures and functional properties of the protein. The cross‐linking between the polyphenol and protein is susceptible to salt (sodium chloride, NaCl) concentrations. Our study investigated the combined effects of quercetin (Q) and NaCl concentrations on wheat gliadin (G) structure and physicochemical properties. RESULTS Q and NaCl addition resulted in a more compact protein microstructure. The improved foaming and emulsifying properties indicated that the modified G might be potent as a novel surface‐active agent. Differential scanning calorimetry analysis indicated that Q protected the thermal stability from destruction at 50 and 200 mmol L−1 NaCl concentrations, with narrower protein denaturation peaks. Fourier transform infrared and the Raman spectral analyses showed the secondary structural and microenvironmental changes of G. NaCl addition imparted a rearrangement of hydrogen bonds in the polypeptide chain and the disorder of protein structure, whereas Q enhanced the transition from β‐sheets and random coils to α‐helices and β‐turns, forming a more ordered structure. Moreover, the interaction between G and Q resulted in significant disulfide bridges conformational rearrangements in the protein. CONCLUSION The results showed the benefits of natural food additives in food processing, which might have potential in improving the structure and physicochemical properties of protein‐based foods. © 2020 Society of Chemical Industry

Highly Efficient Deamidation of Wheat Gluten by Glucose-Citric Acid-Based Natural Deep Eutectic Solvent: A Potential Effective Reaction Media

“…Disulfide bridges could be classified into three different spectral ranges (500–515, 515–525, and 525–545 cm –1 ), which represented the orientational sequence of g–g–g, g–g–t, and t–g–t, respectively. The conformation of g–g–g was regarded as the most energetically stable and associated with interchain disulfide bonds, whereas g–g–t was related to the intrachain disulfide bonds in wheat gluten . Multipeak Gaussian fitting was used to analyze the deconvolution of the disulfide bridges spectral region to obtain the band profiles of the Gaussian components for each sample .…”

“…The conformation of g−g−g was regarded as the most energetically stable and associated with interchain disulfide bonds, whereas g−g−t was related to the intrachain disulfide bonds in wheat gluten. 43 Multipeak Gaussian fitting was used to analyze the deconvolution of the disulfide bridges spectral region to obtain the band profiles of the Gaussian components for each sample. 43 As shown in Figure 4D-4, the percentages of disulfide bridges in the native wheat gluten (CK) were 88% g− g−g and 12% t−g−t, which suggested that the tertiary structure of native wheat gluten was stable.…”

“…43 Multipeak Gaussian fitting was used to analyze the deconvolution of the disulfide bridges spectral region to obtain the band profiles of the Gaussian components for each sample. 43 As shown in Figure 4D-4, the percentages of disulfide bridges in the native wheat gluten (CK) were 88% g− g−g and 12% t−g−t, which suggested that the tertiary structure of native wheat gluten was stable. Compared with CK, the percentage of t−g−t in GDWG and WDWG increased to 41% and 46%, respectively, which demonstrated that GDWG and WDWG formed more unstable disulfide bonds.…”

Insights from multi-spectroscopic analysis and molecular modeling to understand the structure–affinity relationship and the interaction mechanism of flavonoids with gliadin

“…15 Wang et al investigated the combined effects of quercetin and NaCl concentration on the wheat gliadin structure and physicochemical properties, and emphasized the benefit of natural food additives in food processing. 16 Until now, to the best of our knowledge, there are seldom studies systemically concentrated on elucidating the interaction between dietary flavonoids and gliadin. Therefore, in the present study, the relationship of the molecular structure and the binding affinity between a series of flavonoids (structure seen in Fig.…”

“…15 Wang et al investigated the combined effects of quercetin and NaCl concentration on the wheat gliadin structure and physicochemical properties, and emphasized the benefit of natural food additives in food processing. 16…”