Optimization of ultrasound-assisted extraction of crude polysaccharides and polyphenols from passion fruit peels

Abstract

Introduction: This study aimed to optimize the conditions of ultrasound-assisted extraction to simultaneously obtain the highest yields of polysaccharides and polyphenols from passion fruit (Passiflora edulis) peels.

Methods: Box–Behnken design (BBD) and response surface methodology were employed for the optimization. The factors and their levels studied in BBD included a solvent-to-solid ratio (X1) of 30-70 mL/g, an ultrasonic temperature (X2) of 40-70°C and an ultrasonic duration (X3) of 40-70 min.

Results: The results revealed that the optimal conditions were an X1 of 53.9 mL/g, an X2 of 57.6°C, and an X3 of 57.0 min. Under these optimized conditions, the predicted yields of polysaccharides and polyphenols were 36.46% and 48.35 mg gallic acid equivalent (GAE)/g, respectively. The experimental data, which were 35.76 ± 1.54% and 47.51 ± 1.77 mg GAE/g, respectively, agreed well with the predicted data and hence validated the good fit of the models.

Conclusion: This study demonstrated that the ultrasound-assisted extraction method could be effective and ecologically benign for extracting bioactive compounds and natural ingredients from agricultural sources.