Punicalagin-enriched edible coatings from revalorized pomegranate peels for quality enhancement of fresh-cut celery.

Abstract

Background: Pomegranate peel is a rich source of phenolics, particularly punicalagin, but its valorization for fresh produce preservation requires stabilization. This study aimed to develop and evaluate freeze-dried encapsulates of pomegranate peel extracts as ingredients in edible coatings for fresh-cut celery. Pomegranate peels were extracted with ethanol and encapsulated using maltodextrin, inulin, or pectin at wall-to-core ratios of 1:1 and 0.5:1. Extracts and encapsulates were characterized for color, total phenolic content (TPC), antioxidant capacity, and punicalagin (Pn). Edible coatings containing the encapsulates were applied to minimally processed celery sticks by dipping, and quality was monitored over 13 days at 4 °C for physicochemical and nutritional quality.

Results: Ethanolic extraction concentrated phenolics (TPC 246.8 mg kg^-1; Pn 85.3 g kg^-1), and encapsulation with inulin at a 0.5:1 ratio yielded the highest phytochemical retention (TPC 120.8 mg kg^-1; Pn 43.4 g kg^-1). Coated celery showed reduced discoloration (color change (ΔE) approximately 8 vs approximately 13 in an uncoated control (CTRL)) and weight loss (~0.5% vs ~2% in CTRL). Enriched coatings preserved TPC (~0.12 mg GAE kg^-1 vs ~0.08 mg GAE kg^-1 in CTRL) and increased celery Pn content, which peaked at ~1.8 g kg^-1 on day 9.

Conclusion: Encapsulated pomegranate peel extracts provided bioactive fortification and helped to maintain the physicochemical quality of fresh-cut celery during refrigerated storage, offering a sustainable valorization strategy for agro-industrial by-products. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.