Nettle seed gum (NSG) as a new source of hydrocolloid was achieved through the scraping technique, and its physicochemical, rheological and functional properties were characterized. Chemical analysis showed that NSG consisted of 9.5 ± 0.4% (w.b.) moisture, 15.3 ± 0.76% (d.b.) ash, 10.42 ± 0.12% (d.b.) protein, 63.09 ± 1.69% (d.b.) carbohydrate, 1.02 ± 0.87% (d.b.) lipid, and 10.75 ± 0.98 (d.b.) uronic acid. Galacturonic acid (24.71 ± 0.74) and rhamnose (13.98 ± 0.50) were the major sugars comprising the gum. The observation of glycoside bonds and carboxyl, hydroxyl and, methyl groups in the FT-IR spectra indicated NSG as a typical polyelectrolyte. 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of NSG at a concentration of 1000 μg/mL was 38.1%. Water absorption capacity (%) of NSG and Nettle seeds were obtained as 261 ± 0.81 and 301.58 ± 0.38, respectively. The NSG solubility increased from 61.70 ± 1.23% to 68.36 ± 0.66% when the temperature elevated from 30 to 60 °C, and it showed a decrease at higher temperatures. By increasing the NSG concentration from 0 to 2% w/w, emulsion capacity and emulsion stability were increased from 7.16 ± 0.76% to 17.16 ± 0.35% and 55 ± 1.63% to 96.33 ± 1.24%, respectively. This is while the foaming capacity and foaming stability were decreased from 62.66 ± 1.24 to 58.66 ± 1.88% and 65.66 ± 1.69 to 52.33 ± 2.05%, respectively. The surface tension and interfacial tensions values were reduced from 56.07 ± 0.43 to 51.43 ± 1.47 mN/m and 10.11 ± 0.75 to 7.08 ± 0.1 mN/m, respectively, as the NSG concentration increased from 0.25% to 2.0%. At all concentrations (3, 3.5, 4, 4.5, and 5%) and temperatures (10, 25, 40, 55 and 70 °C), NSG indicated a shear-thinning behavior. Amongst the studied models, the Herschel-Bulkley model well described the rheological behavior of the NSG dispersions at all selected concentrations and temperatures. Based on the results of this paper, NSG can be suggested as an emulsion/foam stabilizer in food and pharmaceutical systems.

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