Cao Shi-Lin, Zheng Wen-Yu, Chen Zhan-Peng, Zhang Feng-Li, Jiang Wen-Hao, Qiu Yu-Qiong, Gu Ming, Chen Zi-Shi, Zheng Tian-Yi, Zhang Hong-Kun, Wang Shao-Yun, Liao Lan
Department of Food Science, Foshan University, Foshan, Guangdong 528000, The People's Republic of China.
College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350108, The People's Republic of China.
J Agric Food Chem. 2021 Mar 24;69(11):3452-3465. doi: 10.1021/acs.jafc.0c07275. Epub 2021 Mar 16.
An efficient technique using citric acid and glucose based natural deep eutectic solvent (G-C-NADES) was developed to obtain ultrahigh deamidated wheat gluten (UDWG) (deamidation degree (DD) > 90%). FTIR and H NMR indicated intensive hydrogen bonds (HBs) in G-C-NADES supermolecules. Quantum chemical calculations and molecular dynamic simulations demonstrated that 10 wt % diluted G-C-NADES still had a myriad of HBs. Physicochemical results showed UDWG had DD up to 92.45% after G-C-NADES deamidation, that is, 22% higher than citric-acid-DWG with a weak degree of hydrolysis (1.75%). Conformational characterization demonstrated the obvious conversion from α-helix to β-sheet via FTIR, the least amount of disulfide bonds by Raman spectra, and more exposure of tryptophan residues by fluorescence measurement for UDWG. It is proven that enhanced accessible conformation of WG reached with HBs of G-C-NADESs could contribute to the improvement on nucleophilic attack of deamidation, declaring that G-C-NADES might be a potential solvent for obtaining an ultrahigh deamidation for WG to successfully guarantee the safety of wheat gluten based cereal food regarding to lowering its allergy.
开发了一种使用柠檬酸和葡萄糖基天然低共熔溶剂（G-C-NADES）的高效技术来获得超高脱酰胺度小麦面筋（UDWG）（脱酰胺度（DD）>90%）。傅里叶变换红外光谱（FTIR）和核磁共振氢谱（H NMR）表明G-C-NADES超分子中存在大量氢键（HBs）。量子化学计算和分子动力学模拟表明，10 wt%稀释的G-C-NADES仍有大量氢键。物理化学结果表明，G-C-NADES脱酰胺后UDWG的脱酰胺度高达92.45%，即比水解度较弱（1.75%）的柠檬酸-DWG高22%。构象表征表明，通过FTIR可明显观察到UDWG从α-螺旋向β-折叠的转变，拉曼光谱显示二硫键数量最少，荧光测量表明色氨酸残基的暴露程度更高。事实证明，G-C-NADES的氢键增强了小麦面筋（WG）的可及构象，有助于改善脱酰胺的亲核攻击，这表明G-C-NADES可能是一种潜在的溶剂，用于获得超高脱酰胺度的WG，从而成功保证基于小麦面筋的谷物食品在降低过敏方面的安全性。
