Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, PR China.
Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, PR China.
Food Chem. 2023 Apr 16;406:135043. doi: 10.1016/j.foodchem.2022.135043. Epub 2022 Nov 23.
d-Histidine (d-His), l-Histidine (l-His), and their racemic compound dl-Histidine (dl-His) have different stereo chirality, making them intrinsic diverse functionalities to the living system. Identifying the configuration and crystal structures of enantiomers and the racemic compound is always the foremost requirement in processing protein foods. Although these features can be analyzed by spectroscopic technologies individually, it remains challenging to incorporate these complex methods into a facile analytical strategy. Herein, we propose a terahertz spectroscopy with solid-state density functional theory to both distinguish the configurational difference and quantify the crystal transformation from l-His and d-His to dl-His. By comparison with X-ray diffraction analysis, the validity of the crystal transformation evaluation based on terahertz spectroscopy is verified. A normalized fitting line regarding the terahertz absorption frequency and intensity is calculated to quantitatively elucidate the crystal transformation from enantiomers to dl-His. Our findings provide a new analytical approach to the research on food chemistry.
d-组氨酸 (d-His)、l-组氨酸 (l-His) 和它们的外消旋化合物 dl-组氨酸 (dl-His) 具有不同的立体手性，使它们对生命系统具有内在的多样化功能。确定对映异构体和外消旋化合物的构型和晶体结构始终是加工蛋白质食品的首要要求。尽管这些特征可以通过单独的光谱技术进行分析，但将这些复杂方法纳入简便的分析策略仍然具有挑战性。在这里，我们提出了一种太赫兹光谱与固态密度泛函理论相结合的方法，以区分 l-组氨酸和 d-组氨酸到 dl-组氨酸的构象差异和定量晶体转化。通过与 X 射线衍射分析进行比较，验证了基于太赫兹光谱的晶体转化评价的有效性。计算了太赫兹吸收频率和强度的归一化拟合线，以定量阐明从对映异构体到 dl-组氨酸的晶体转化。我们的研究结果为食品化学研究提供了一种新的分析方法。
