Water-Soluble Polysaccharides from <i>Ephedra alata</i> Stems: Structural Characterization, Functional Properties, and Antioxidant Activity

• Main Authors: Leila Soua, Mohamed Koubaa, Francisco J. Barba, Jawhar Fakhfakh, Hanen Kolsi Ghamgui, Semia Ellouz Chaabouni
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Molecules
• Subjects: <i>Ephedra alata</i>; polysaccharides; physicochemical characterization; functional properties; antioxidant activities
• Online Access: https://www.mdpi.com/1420-3049/25/9/2210

In this study, the physicochemical characterization, functional properties, and antioxidant activity of polysaccharides extracted from <i>Ephedra alata</i> (EAP) were investigated. EAP were extracted in water during 3 h with a liquid/solid ratio of 5 in a water bath at 90 °C. The structure of the extracted EAP was examined by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and gas chromatography-mass spectrometry (GC-MS). The functional properties and biochemical activities of EAP were determined. The chemical analysis revealed that the contents of carbohydrates, uronic acid, and proteins were 73.24% ± 1.24%, 6.82% ± 0.57%, and 6.56% ± 0.36%, respectively. The results showed that the extracted EAP essentially contain three functional groups: C=O, C-H, and O-H. SEM images showed that EAP present numerous high porosity particles. The monosaccharide composition revealed a polymer composed of glucose (43.1%), galactose (36.4%), mannose (14.9%), arabinose (3.7%), and gluconic acid (1.7%). EAP showed interesting functional properties (solubility, oil holding capacity, foaming and emulsion properties). Finally, the results revealed that EAP displayed excellent antihypertensive and antioxidant activities. Overall, EAP present a promising natural source of food additives, antioxidants, and antihypertensive agents.