Interaction mechanism of theaflavin and various proteins on influence of tea cream formation: A study on spectroscopic measurements and molecular docking

• Published in: Food science & technology 2024-07, Vol.204, p.116426, Article 116426
• Main Authors: Xie, Jizhou, Luo, Liyong, Yu, Xia, Zhong, Shuping, Yue, Rongbosen, Zhang, Ying, Luo, Wei, Zeng, Liang
• Format: Article
• Language: English
• Subjects: Molecular interactions; Proteins; Spectrometry measurements; Theaflavin; TOPSIS
• ISSN: 0023-6438
• DOI: 10.1016/j.lwt.2024.116426

In black tea beverage, the interaction between theaflavins (TFs) and proteins may lead to the precipitates’ formation, affecting its clarity and shelf life. This study investigated interactions between TF and five exogenous proteins (β-lactoglobulin (β-Lg), zein, soy protein isolate, gelatin and collagen) by spectrometry measurements. The technique for order preference by similarity to an ideal solution (TOPSIS) was applied to select the optimal protein and TF concentration to prepare a high-TF tea beverage with high clarity. The results showed TF interact with forementioned proteins via static quenching process and the optimal combination was β-Lg:200 mg/L and TF:200 mg/L. Noticeably, the selected TF concentration (200 mg/L) was 1.5 times higher than that of commercial tea beverage (80 mg/L). To obtain further insight of β-Lg-TF complexes, UV–visible absorption and Circular dichroism spectroscopy were used to investigate the secondary structures changes in β-Lg and molecular docking demonstrated the binding modes and main interaction forces of TF-β-Lg. •The quenching mechanism of five proteins by TF is static, respectively.•The optimal solution (TF of 200 mg/L with β-Lg) was selected by TOPSIS method.•The selected TF concentration of 200 mg/L is much higher than that of commercial tea beverage.•Hydrophobic interaction and hydrogen bond were main binding forces of TF - β-Lg.