Biomacromolecule-based encapsulation of Hibiscus sabdariffa polyphenols for functional foods and nutraceuticals

Abstract

Hibiscus sabdariffa is recognized not only as a source of bioactive polyphenols but also as an underutilized biomass resource. This review examines an integrated valorization approach that connects phytochemical variability and extraction strategies with biomacromolecule-based encapsulation for functional foods and nutraceuticals. Anthocyanins, flavonoids, phenolic acids, and organic acids vary among plant parts, accessions, and processing residues, highlighting the importance of residue-specific recovery and preservation. Extraction technologies can improve recovery, but higher extraction efficiency may compromise thermolabile anthocyanins, so recovery should be balanced with chemical integrity. Encapsulation approaches, including spray drying, freeze drying, calcium alginate gelation, carbohydrate and protein matrices, liposomes, polymeric systems, and nanostructured lipid carriers, provide options for improving the stability, handling, dispersibility, and gastrointestinal delivery of Hibiscus sabdariffa bioactive compounds. However, evidence specifically linking these encapsulation systems to residue-derived H. sabdariffa bioactives remains limited. Future research should integrate residue-specific extraction with food-compatible carrier design, quantitative release kinetics, bioaccessibility testing, scale-up, and sustainability to support the development of value-added roselle-derived ingredients while preserving sensory quality and commercial potential.