Optimización de la extracción de polifenoles totales en hojas de Psidium guajava

Polyphenols constitute a group of bioactive compounds of remarkable importance, which are widely found in the plant kingdom. In this study, the ultrasound extraction of total polyphenols in Psidium guajava leaves was optimized using response surface methodology. The concentration of polyphenols was determined by the Folin-Ciocalteu method. The effect of temperature, time and ultrasonic amplitude on polyphenol extraction was evaluated using a Box-Behnken design. Optimal extraction conditions were determined by response surface analysis. The quadratic model presented the best fit with adjusted and predicted R² values of 0.9927 and 0.9582, respectively. Temperature, time and amplitude exerted a significant (p<0.05) and positive effect on extraction yield. The optimum extraction conditions that maximized polyphenol content were: temperature 46.55°C, time 28.12 minutes and ultrasonic amplitude 67.20%, resulting in a predicted content of 1.76 g EAG/100 g. These results contribute to establish optimal conditions for the extraction of polyphenols, which is fundamental to take advantage of the nutraceutical and pharmacological potential of Psidium guajava leaves.