The antioxidant potential of roselle (Hibiscus sabdariffa L.) extracts was studied. Different plant organs, including seeds, stems, leaves, and sepals, were analyzed with respect to their water-soluble antioxidant capacity, lipid-soluble antioxidant capacity, and tocopherol content, revealing that roselle seeds are a good source of lipid-soluble antioxidants, particularly gamma-tocopherol. Roselle seed oil was extracted and characterized, and its physicochemical parameters are summarized: acidity, 2.24%; peroxide index, 8.63 meq/kg; extinction coefficients at 232 (k(232)) and 270 nm (k(270)), 3.19 and 1.46, respectively; oxidative stability, 15.53 h; refractive index, 1.477; density, 0.92 kg/L; and viscosity, 15.9 cP. Roselle seed oil belongs to the linoleic/oleic category, its most abundant fatty acids being C18:2 (40.1%), C18:1 (28%), C16:0 (20%), C18:0 (5.3%), and C19:1 (1.7%). Sterols include beta-sitosterol (71.9%), campesterol (13.6%), Delta-5-avenasterol (5.9%), cholesterol (1.35%), and clerosterol (0.6%). Total tocopherols were detected at an average concentration of 2000 mg/kg, including alpha-tocopherol (25%), gamma-tocopherol (74.5%), and delta-tocopherol (0.5%). The global characteristics of roselle seed oil suggest that it could have important industrial applications, adding to the traditional use of roselle sepals in the elaboration of karkade tea.

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Resumen Por primera vez reportamos en Venezuela la presencia de Aceria hibisci (Nalepa, 1906) (Acari: Eriophyoidea) en plantas de cayena (Hibiscus rosa-sinensis L: Malvaceae). El ácaro induce el desarrollo de agallas que resultan en la aparición de notables alteraciones estéticas y disminución acentuada de la capacidad fotosintética. La especie Aceria hibisci está presente en todas las áreas correspondientes al Municipio Libertador, estado Mérida y muchas de estas plantas de cayenas han muerto. La identificación fue posible mediante el registro de imágenes de microscopía electrónica de barrido y el consiguiente análisis de las características taxonómicas. Abstract For the first time, we report in Venezuela the presence of Aceria hibisci (Nalepa, 1906) (Acari: Eriophyoidea) in cayenne plants (Hibiscus rosa-sinensis L: Malvaceae). Mites induce the development of galls that result in the appearance of remarkable aesthetic alterations and a sharp decrease in photosynthetic capacity. The Aceria hibisci specie is present in all corresponding areas of the Libertador Municipality, Mérida state, and many of these plants of “Cayenas” have died. Identification was possible by recording images of scanning electron microscopy and the consequent analysis of taxonomic characteristics.