Evaluation of Chemical, Nutritional and Antioxidant Characteristics of Roselle (Hibiscus sabdariffa L.) Seed

Abstract

A B S T R A C TBackground and Objectives: Roselle (Hibiscus sabdariffa L.) is one of the valuable plants grown in tropical and subtropical regions such as some parts of Iran. Roselle calyces are commonly used to make herbal tea as well as a natural food color additive. However, Roselle seeds are usually discarded as by-products, while they can be used as a source of nutritious and functional compound. Therefore, in the current study, some of the chemical and nutritional characteristics of Iranian Roselle seed were investigated. In addition, the effects of different extracting solvents on seed extraction yield, total phenol content (TPC) and antioxidant activity (scavenging ability) of the extracts were evaluated. Materials and Methods:Some chemical and nutritional properties of Roselle seeds such as moisture, protein, total fiber and lipid contents were determined. Also, fatty acid composition of the oil was determined using gas chromatography. The effects of different solvents including acetone, methanol and water, on yield, TPC (Folin-Ciocalteu assay) and antioxidant activity (DPPH and ABTS methods) of Roselle seeds were also investigated. Results:The results showed that the Roselle seeds are the main sources of protein, lipid and fiber (26.62±0.03%, 21.03±0.02% and 19.81±0.01%, respectively). Linoleic (41.06±0.7%), oleic (27.07±0.01%) and palmitic (21.9±0.03%) acids are the main fatty acids in the Roselle seeds oil. The maximum yield (20±0.02%), related to aqueous extract, however, higher TPC (201±0.02 mg GAEs/100 g) and antioxidant activity (DPPH, 94.15±0.2%; ABTS, 75.91±0.03%) were observed in acetone extract. Conclusions:According to the results, Roselle seeds are a good source of protein, fiber and oil, which contains unsaturated fatty acids especially linoleic acid. In addition, the acetone extract showed the highest TPC and antioxidant activity among other extracts.

Phyto-chemistry and Pharmacological Activities of Hibiscus sabdariffa Linn.-A Review

“…The family consists of 243 genera and Hibiscus is among the largest genera in terms of number of species [7,15]. The species of this genus (Hibiscus) are well known for their showy flowers and thus known as Hibiscus or Rose mallow [16,17]. A large number of epidemiological studies showed that the use of antioxidant vitamins and carotenoids inhibits the development of cancer [18][19]9], coronary heart disease [20], atherosclerosis [21] and hepatoprotective [22].…”

Substrates and Temperatures in the Germination of Hibiscus sabdariffa L. Seeds

“…The main fatty acids identified are linoleic (39.31%), oleic (32.06%), palmitic (20.84%) and stearic (5.88%). Besides seeds, leaves and calyxes are widely used in cooking and traditional medicine in countries such as Mexico, India, England, China and Brazil (Nasrabadi, Zarringhalami, & Ganjloo, 2018;Singh, Khan, & Hailemariam, 2017;Nzikou et al, 2011l).…”

Kenaf (Hibiscus cannabinus L.) Seed and its Potential Food Applications: A Review

“…Several studies have reported the crude protein content of kenaf seed as ranging from 21.4% to 30.5% (Alexopoulou et al, 2013;Kim et al, 2018;Mariod et al, 2010;Nyam et al, 2009;Olawepo et al, 2014), similar to the protein composition of hemp seed, that is, 23.8% to 28.0% (Vonapartis et al, 2015). These values are higher than the protein content of Roselle seed (14.9%) (Nyam et al, 2009) but are lower than the values of 33.5% and 26.62% reported by Hainida, Amin, Normah, and Esa (2008) and Mokhtari, Zarringhalami, and Ganjloo (2018), respectively for crude protein of Roselle seed. The defatted kenaf seed has higher protein content (ranging from 74.4% to 81.4%) than the whole seed (Mariod et al, 2010).…”