Roselle (Hibiscus sabdariffa) Seed Oil Is a Rich Source of γ‐Tocopherol

Abstract

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.

Antioxidant Activity and Nutritional Value of Roselle Seeds Flour

“…However, in Africa, they are ground into meal for human food due to their high protein content. They are also roasted to use as a substitute for coffee (Morton, 1987) and contain a substantial amount of oil that resembles that of cotton seed (Mohammed et al, 2007 andKarma andChavan, 2016).…”

Roselle Calyx Ethanol Extract Stimulates Oral Mucosal Wound Healing

“…This is likely due to the anti-inflammatory activity of roselle calyxes. This research was support by many former studies that reported that roselle calyxes consist of flavonoids such as gossypetin, hibiscetine, and sabdaretin, and are also good sources of lipid-soluble antioxidants [6] and gamma tocopherols [15]. Direct evidence supports the anti-inflammatory efficacy of roselle and its capacity to reduce vasodilatation and to improve edematous conditions, thereby reducing inflammation [2][3][4]6].…”

“…The phytochemical, pharmacological, and toxicological properties of roselle are related to the steroids, alkaloids, saponins, flavonoids, tannins [3,11,12,15], and polyuronides contained in this plant [8]. Previous studies reported that saponin extracted from ginseng, for example, accelerates neovascularization in burn wounds on the skin of mice through a reduction in neutrophil entry to wounds, therefore lessening chronic inflammatory reactions [4,6,10].…”

“…In this stage, macrophages increase their metabolism on activation and begin to release products that act as intermediaries of the inflammatory process [4,7,10,13]. However, some animals can still show persistent inflammation resulting from secondary infection by other oral bacteria following surgical injury, which slows the repair process of labial mucosa [3,6,15].…”

Physicochemical properties, phenolic acids and volatile compounds of oil extracted from dry alhydwan (<em>Boerhavia elegana Choisy</em>) seeds

“…The results strongly suggest that the B. elegana Choisy seed oil is a rich source of α-tocotrienol (α-T3), also similar to palm oil (Al-Saqer et al, 2004). It should be noted that tocopherols and tocotrienols have antioxidant properties and they are active as vitamin E, whose deficiency affects hemolysis in humans and nervous system development in children (Mohamed et al, 2007).…”