Translating Plant Secondary Metabolites into Functional Foods through Mechanistic Validation, Process-Fit Formulation, and Regulatory Alignment

The mechanistic evidence for bioactivity of plant secondary metabolites (PSMs) is robust and broadly documented; however, their translation into functional foods faces a practical bottleneck, such as low bioaccessibility and stability, variability in dose and source, matrix interactions that alter efficacy, sensory liabilities (bitterness, astringency, and pungency), and fragmented regulatory frameworks. This review proposes a three-pillar translational blueprint: human-centered mechanistic validation, process-aligned formulation innovation (encapsulation, lipid systems, protein–polyphenol complexes, matrix and process design), and regulatory alignment, and surveys major PSM classes, their mechanisms, and scalable delivery systems. We integrate safety considerations, analytical standardization, consumer acceptance, personalization via omics/microbiome, and opportunities in the circular bioeconomy. Together, these elements guide the development of stable, palatable, and claim-ready products that shift biomarkers at realistic intake levels.