Zhang Bo, Liu Rui, He Fei, Zhou Pan-Pan, Duan Chang-Qing
Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China.
College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
Food Chem. 2015 Mar 1;170:226-33. doi: 10.1016/j.foodchem.2014.08.026. Epub 2014 Aug 18.
In the present research, the copigmentations of malvidin-3-O-glucoside with five hydroxybenzoic cofactors (p-hydroxybenzoic acid, protocatechuic acid, gallic acid, vanillic acid, and syringic acid) were investigated. The influence of the concentration of these cofactors and the reaction temperature was examined. The equilibrium constant (K), stoichiometric ratio (n) and the thermodynamic parameters (ΔG°, ΔH°, ΔS°) related to the copigmentation were also reported here. Theoretical calculations were performed to identify the relative arrangement between the pigment and cofactors in the copigmentation complexes. Besides, the comparison of the relative binding free energies (ΔΔGbinding) derived from the theoretical calculations and experimental data were made, and the binding strength of these copigmentation complexes was discussed with the interaction energies (ΔE). AIM analysis was also used to explore the main driving forces contributing to the copigmentation. In the comparison of the five studied cofactors, syringic acid had a stronger copigmentation effect than the other four phenolic acids investigated.
在本研究中，研究了锦葵色素 - 3 - O - 葡萄糖苷与五种羟基苯甲酸辅助色素（对羟基苯甲酸、原儿茶酸、没食子酸、香草酸和丁香酸）的共色素化作用。考察了这些辅助色素浓度和反应温度的影响。本文还报道了与共色素化相关的平衡常数（K）、化学计量比（n）和热力学参数（ΔG°、ΔH°、ΔS°）。进行了理论计算以确定共色素化复合物中色素与辅助色素之间的相对排列。此外，对理论计算得出的相对结合自由能（ΔΔGbinding）与实验数据进行了比较，并利用相互作用能（ΔE）讨论了这些共色素化复合物的结合强度。还采用AIM分析来探究促成共色素化的主要驱动力。在对所研究的五种辅助色素的比较中，丁香酸的共色素化效果比其他四种所研究的酚酸更强。
