Cranberry Pomace Valorization: Composition, Extraction, Bioactivity, and Food Applications

Cranberry pomace, the principal solid residue generated during cranberry processing, is increasingly recognized as a compositionally valuable coproduct rather than a waste material. This is particularly relevant in North America, where cranberry production is concentrated in the United States and Canada, the two leading producing countries. This review critically evaluates its chemical composition, recovery of valuable constituents, biological properties, and food-related applications. Cranberry pomace retains substantial amounts of anthocyanins, flavonols, proanthocyanidins, and phenolic acids, together with a major dietary fiber fraction rich in structurally diverse polysaccharides and a smaller lipophilic fraction containing unsaturated fatty acids, tocochromanols, and triterpenoids. Ethanol-based solvent extraction remains the most established practical baseline, whereas ultrasound-assisted and pressurized liquid extraction offer improved recovery efficiency and shorter processing times. However, most extraction studies remain laboratory-based, with limited pilot-scale, environmental, and economic validation. Biological evidence is predominantly preclinical and is strongest for antioxidant, antimicrobial, and antiproliferative effects of phenolic-rich fractions, while mechanistic evidence and human studies are scarce. Food applications include extruded and bakery products, fermented dairy-type systems, and active or edible packaging, where cranberry pomace may provide fiber enrichment, natural color, and oxidative or microbial protection. Key priorities include standardized compositional reporting, gastrointestinal bioaccessibility studies, mechanistic and clinical validation, food-grade scale-up, and techno-economic and environmental assessment. Cranberry pomace, therefore, represents a promising source of value-added constituents. Still, wider utilization will depend on stronger evidence linking composition and processing to biological efficacy, product performance, and industrial feasibility.