Roselle composition and points of caution
Review2026 critical reviewHibiscus sabdariffa calyces, food and cosmetic uses
The calyces are rich in anthocyanins, organic acids, polysaccharides and minerals. The authors point out the variability of cyanogenic glycosides, gaps in microbiological monitoring and an almost complete lack of allergenicity data2.
A flower extract in a gel: release and stability
LaboratoryFlower extract in a nanoemulgelIn vitro release, 12-month stability
The extract is released at about 99% in 24 h. The sodium alginate gel stays stable for 12 months at 4-8 °C in glass; high temperatures and plastic packaging destabilize it4.