Structural and physicochemical characterization, technological properties, and prebiotic potential of an acidic polysaccharide extracted from the aerial parts of Eryngium billardieri

Polysaccharides have various applications because of differences in their structure and prebiotic properties. Therefore, researchers aim to increase the number of polysaccharides from different sources. This study investigated the prebiotic potential of water-soluble polysaccharides extracted from aerial parts of the medicinal plant Eryngium billardieri. After extracting the polysaccharide using hot water (3 h, 90 °C), its structural, technological, and prebiotic characteristics were evaluated. The total carbohydrate content and polysaccharide yield were 73.87% and 4.43%, respectively. HPLC analysis revealed that glucose (238.72 mg/g) was the predominant monosaccharide. XRD spectra revealed that the polysaccharide has a complex semi-crystalline structure. In terms of technological properties, the E. billardieri polysaccharide (EbP) had high water and oil holding capacity (3.64 and 5.47 g of water and oil per g of polysaccharide, respectively), which was significantly higher than inulin as a standard prebiotic (p < 0.05). The thermogravimetric analysis confirmed its relatively high thermal stability, with 5.6% weight loss at 214 °C. The digestive resistance of this polysaccharide was significantly higher than inulin. The EbP demonstrated significantly superior resistance to digestion, with degradation rates of 5.9% and 3%, respectively, under mimicked gastric (pH 1–4) and small intestinal (pH 5–8, with α-amylase) conditions (p < 0.05). Also, EbP significantly stimulated the growth of Lactobacillus acidophilus compared to the MRS media without a carbon source (negative control) (p < 0.05). Overall, EbP has special structural characteristics, strong prebiotic potential, and appropriate technological features. This makes it a promising candidate for use in the food and pharmaceutical industries.