Optimization of Polydatin Hydrolysis Process Through Response Surface Methodology for Efficient Resveratrol...

Background/Objectives: Resveratrol is a naturally occurring polyphenolic stilbene compound exhibiting a wide range of biological activities, and it has been extensively utilized as both a food additive and a pharmaceutical active ingredient. Typically, it can be directly extracted from natural sources such as grapes, mulberries, and peanuts, or obtained through catalytic hydrolysis of polydatin. To establish an efficient and optimized method for resveratrol production, we conducted a comprehensive study to refine the acid-catalyzed hydrolysis conditions of polydatin. Methods: A high-performance liquid chromatography method was developed for the quantitative determination of polydatin and resveratrol. To identify the optimal ranges of reaction temperature, HCl concentration, and ethanol concentration, single-factor experiments were conducted by evaluating their influences on hydrolysis kinetics and resveratrol yield. Based on these results, response surface methodology incorporating a Box-Behnken design was employed to optimize the hydrolysis process, using resveratrol yield as the response variable. Furthermore, time-course experiments were performed to determine the optimal reaction duration under the established optimal conditions. Results: Single-factor experiments demonstrated that increasing temperature and HCl concentration significantly accelerated hydrolysis, but resveratrol yield increased initially and then decreased with excessive increases in either factor. To further optimize the process, response surface methodology optimization experiments were conducted at temperatures of 60, 70, and 80 °C; HCl concentrations of 1.0, 1.5, and 2.0 M; and ethanol concentrations of 75%, 85%, and 95%. The optimal conditions were identified as follows: temperature, 70 °C; HCl concentration, 1.5 M; ethanol volume fraction 85%; and reaction time, 5 h. Under these conditions, the theoretical resveratrol yield was 85.68%, and the average yield from triplicate validation experiments was 86.01% (RSD = 0.56%), which was consistent with the theoretical value. Conclusions: The optimized acid-catalytic hydrolysis process using RSM is stable, feasible, and efficient, offering a promising approach for enhancing resveratrol production from polydatin.