Interaction of Flavor Nucleotides with EGCG and Their Protein Complexes by UV Absorption Spectrometry and Fluorescence Spectrometry

In order to explore whether IMP and GMP interact with EGCG and its protein complexes to affect the taste characteristics, UV absorption spectrometry and fluorescence spectrometry were used to determine the changes in the spectrum. The results showed that: IMP, GMP interacted with EGCG and changed the spectral characteristics of EGCG, and there was only one binding mode; The interaction between GMP and EGCG was stronger than that between IMP and EGCG, and the two flavor nucleotides had the greatest interactions with EGCG when they were mixed in 1:1.IMP, GMP neither interacted with BSA alone, but when the two existed at the same time, it would produce static fluorescence quenching of BSA, the binding constant was 0.6634, and the number of binding sites was 0.88. In the interaction with EGCG protein complex, GMP existed alone. It only reacted with EGCG. When IMP and GMP coexisted, it mainly interacted with protein. The binding constant was 1.1054 and the number of binding sites was 1.49. This study can provide a clearer understanding of the taste mechanism of tea soup and provide a theoretical basis for the improvement of tea quality and the improvement of tea beverage flavor.