Ultrasound-assisted ethanolic extraction of punicalagin from pomegranate by-products influenced by cultivar, pre-drying treatment, particle size, and temperature

The novelty of this research is to describe the effect of different ultrasound-assisted extraction operating conditions on the punicalagin (Sigma Pn) and total phenolic content (TPC) yield of pomegranate peel of two cultivars: Wonderful (W) and Mollar de Elche (ME). Besides cultivar, drying method (convective and freeze drying), particle size (<56 and 56-101 mu m), extraction temperature (25 and 45 degrees C) and time (0-60 min) were categorical variables included in the experimental design to optimize the process using a polynomial regression model. Both Sigma Pn and TPC extraction was higher in freeze-dried than in convectively dried samples. Although the interaction of the above-mentioned variables must be considered, the type of drying influenced the extraction of Sigma Pn between cultivars, being higher in ME than W when the material was freeze-dried. For the smallest particle size and higher temperature (45 degrees C), the extracted Sigma Pn and TPC was higher than samples with higher particle size and lower extraction temperature (25 degrees C).

Automated summary

This research investigates the effect of different ultrasound-assisted extraction conditions on the extraction yield of key components in two cultivars of pomegranate. The study finds that freeze-dried samples have higher extraction yield compared to convectively dried samples. Additionally, factors such as drying method, cultivar, particle size, and extraction temperature also influence the extraction yield.