Storage Stability and Functional Properties of Pomegranate Peel Extract-Enriched Vinegar Powders

Pomegranate peel is an agro-industrial byproduct rich in phenolic compounds with recognized functional properties. Its incorporation into stable food ingredients represents an attractive strategy for byproduct valorization. This study evaluated spray-dried vinegar powders enriched with pomegranate peel extract obtained by ultrasound-assisted extraction (UAE) using vinegar and α-cyclodextrin (αCD). Non-buffered and buffered formulations were compared with two commercial buffered powders during 6 months of storage at 22 °C. Morphological (particle size distribution and scanning electron microscopy images), physicochemical (pH, titratable acidity, moisture content, water activity and color), antioxidant (total phenolic content and DPPH radical scavenging activity), antimicrobial and sensory properties were evaluated. The powders maintained stable physicochemical properties, with moisture content remaining ≤1.2%, whereas commercial powders reached 3.0-3.9% after storage. Pomegranate-enriched powders showed total phenolic contents of 5.3-27.9 mg GAE/g_powder and antioxidant activity of 37.1-279.3 µmol TE/g_powder, compared with 0.1-0.3 mg GAE/g_powder and 2.3-4.1 µmol TE/g_powder in the non-enriched formulations, while remaining stable throughout storage. Buffered enriched powders maintained in vitro antimicrobial activity against Listeria monocytogenes, whereas only non-buffered formulations inhibited Salmonella enterica. The powders were incorporated into a béchamel croquette formulation and showed preliminary sensory acceptability. These results support spray drying with αCD as an effective strategy for obtaining stable powdered ingredients from pomegranate peel byproducts under the evaluated conditions.