Kinetic Modeling, Comparative Investigations, and a New Approach to Quantifying the Global Extraction Yield of Algerian Pomegranate Peel Phenolic Compounds

The aim of this study was to quantify the total extraction yield (GEY) of polyphenols from pomegranate peels using a solid–liquid extraction process without evaporation but with UV-Vis spectrophotometry. Extraction kinetics models were tested to evaluate the extract yield (GEY), total phenolic compounds (TPCs), total flavonoids (TFCs), and condensed tannins (CTCs). The results showed maximum values of 45% for GEY, 97.560 mg EAG/g db for TPC, 4.416 mg EQ/g db for TFC, and 0.412 mg EC/g db for CTC, obtained with a methanol/water mixture (75/25, v/v) for 24 h. Spectrophotometry proved to be a reliable method for quantifying the total extraction yield, with a correlation of 99.79% compared to the conventional method. The second-order kinetic model accurately described the mass transfer mechanisms of the bioactive compounds studied. This study provides important insights into the mass transfer mechanisms during the extraction of bioactive compounds, facilitating the design, optimization, and control of large-scale processes for the recovery of pomegranate waste.