Abstract: Theaflavins-Aluminum complex was synthesized from theaflavins and AlCl₃.The single-factor and response surface experiments was used to optimization of preparation conditions for Theaflavins-Aluminum complex,the factor parameter including molar ratio of TFs to Al、pH value,reaction time and reaction temperature. In addition,the structure and properties were characterized by infrared spectrometry (IR) and thermogravimetric analysis (TG).The results showed that the main factors affecting Al³⁺ complexation TP are pH value,molar ratio,reaction temperature and reaction time.The optimal process were determined as 0.8,4.3,51 minand 41 ℃ for TFs-Al molar ratio,pH value,reaction time and reaction temperature,respectively.Under these conditions,the combination rate was 94.52%.The actual value was within the range of 95% prediction range of the model response ［91.98%,99.20%］.Infrared spectral analysis showed that Al3+ and TFs formed stable TFs-Al complex,and the thermal stability was better than that of theaflavins (TFs).

Key words: TFs-Al complex, response surface methodology, infrared spectrometry, liquid chromatography, thermogravimetric analysis