诺邓火腿红色素的分离纯化及结构鉴定

为探究诺邓火腿红色素化学本质，采用75%丙酮溶液提取，结合C₁₈固相萃取小柱进行分离纯化，通过紫外-可见光光谱(ultraviolet spectroscopy,UV-Vis)、荧光光谱、超高效液相色谱-串联质谱(ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)、傅里叶变换红外光谱(Fourier transform infrared,FTIR)和核磁共振(nuclear magnetic resonance,NMR)共同表征诺邓火腿红色素的化学结构。结果表明：在UV-Vis中416 nm处有1个强吸收峰，546 nm和584 nm处有2个弱对称吸收峰，符合金属卟啉特征；以420 nm激发，红色素在590 nm处有1个强荧光发射峰，644 nm处有1个弱荧光发射峰，与Zn-原卟啉IX(Zn protoporphyrin IX,ZnPP)标准品比对后高度重合，表明卟啉环中的金属离子是锌离子；在UPLC-MS/MS的正离子(m/z 625.177 9M+...

Isolation,Purification and Structural Identification of Red Pigment from Nuodeng Ham

In order to explore the chemical nature of red pigment in Nuodeng ham, the red pigment was extracted with 75% acetone aqueous solution and purified using a C18 solid phase extraction column, and its chemical structure was characterized by using ultraviolet-visible (UV-Vis) spectroscopy, fluorescence spectroscopy and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The UV-Vis spectrum showed a strong absorption peak at 416 nm and two weakly symmetrical absorption peaks at 546 and 584 nm, which are characteristic of metalloporphyrins. When it was excited at 420 nm, the red pigment exhibited a strong fluorescence emission peak at 590 nm and a weak fluorescence emission peak at 644 nm, which highly coincided with those of Zn protoporphyrin IX (ZnPP) standard, indicating that the metal ions in the porphyrin ring were zinc ions. ZnPP was detected by UPLC-MS/MS in both positive (m/z 625.177 9 M + H]+) and negative ion (m/z 623.161 4 M-H]–) modes, and the stretching vibrations of characteristic functional groups on the porphyrin ring such as –CH3, –CH2–, C=O, –C–OH in carboxyl groups, C–H on olefin and porphyrin ring C=N were observed in the FTIR spectrum. In addition, the 1H-NMR results of the red pigment were consistent with the structure of the target compound ZnPP. Therefore, the red pigment in Nuodeng ham was identified as ZnPP. The results of this study provide a theoretical basis for the color regulation of Nuodeng ham.