Recovery of pomegranate (Punica granatum L.) juice polyphenols using ultrafiltration and adsorption chromatography

Introduction

The pomegranate (Punica granatum L.) is an ancient fruit native to Persia and Central Asia. The juice is widely produced for its nutritional and functional properties, chiefly attributed to its high content of natural antioxidants such as punicalagins, ellagic acid, and derivatives.

This study focuses on the recovery of polyphenols from pomegranate juice using integrated separation processes, combining ultrafiltration for clarification and adsorption chromatography for selective concentration of polyphenolic compounds.

Material and methods

Commercial pomegranate (Punica granatum L.) juice was used as feedstock for polyphenol recovery. The juice was first clarified by ultrafiltration and subsequently processed by adsorption chromatography for selective concentration of polyphenols. The resulting enriched fractions were then stabilized by spray drying to obtain polyphenol-rich powders. Polyphenolic composition of the extracts was characterized by HPLC coupled with a diode array detector. Experiments were performed in duplicate.

Results and discussion

Ultrafiltration and adsorption chromatography enabled efficient recovery of polyphenols from pomegranate juice. Ultrafiltration provided a clarified feed with reduced dissolved solids for adsorption processing. Resin loading strongly affected performance: high loading (near saturation) resulted in polyphenol losses of ~30–40% due to breakthrough, while intermediate conditions showed variable efficiency. The best results were obtained at partial loading (~50% capacity), achieving 90–95% polyphenol recovery, <10% losses in the effluent, and extract purity of ~80–85% Total polyphenols (dry basis). Overall, sub-saturation operation improved selectivity, mass transfer, and process stability compared to resin overloading.

The finished powdered native extract obtained by spray drying showed a characteristic chromatographic profile of Punica granatum fruit. Compared with the initial pomegranate juice, the extract showed an approximately 13-fold increase in punicalagin content, rising from 0.29% to 3.69% on a dry basis.

Conclusions

Partial loading of the adsorption column (~50% capacity) provided optimal performance for pomegranate polyphenol recovery, achieving 90–95% recovery, low losses, and high-purity extracts. Full loading reduced efficiency due to resin saturation and breakthrough.