A new acidic polysaccharide (PLP) was isolated and characterized from Plantago asiatic L. seeds by hot alkali extraction and chromatographic purification using DEAE cellulose and Sephacryl S-400 columns. PLP has a molecular weight of 1.15 × 10(6) Da, and a monosaccharide composition of xylose (Xyl), arabinose (Ara), glucuronic acid (GlcA), and galactose (Gal) in a molar ratio of 18.8:7.2:6.1:1. The results of methylation analysis, FT-IR, and 1D and 2D NMR indicated that PLP was a highly branched heteroxylan of β-1,4-linked Xylp backbone with three α-GlcAp-(1→3)-Araf attached to the O-3 position and one α-T-linked-GlcAp and one α-Araf-(1→5)-Araf attached to the O-2 position every eight monosaccharide residues. PLP exhibited scavenging abilities against hydroxyl, peroxyl anion, and DPPH radicals in vitro and showed significant binding capacities against cholic and chenodeoxycholic acids, suggesting its possible cholesterol-lowering activity. The results demonstrated the potential use of PLP in functional foods and nutraceuticals.

Alkaline hydrogen peroxide (AHP) was investigated to enhance the content and functionality of soluble dietary fiber (SDF) extracted from black bean coats. Compared with the content of SDF of original black bean coat 7.8%, the content of SDF of modified black bean coat was 16.9% after treated by 15% H 2 O 2 (v/v) at pH 11 and 1:18 (w/v) as liquid-to-solid ratio for 0.5 h. Monosaccharide composition confirmed that the ratio of galacturonic acid in modified SDF (M-SDF) was higher than that of original SDF (O-SDF), and M-SDF was also with smaller molecular weight (Mw) of 1.24 ×10 6 Da and lower ζ-potential of −42.3 mV. Other structural characters were determined by FT-IR and TEM. In the range of 2-6% (w/v), both O-SDF and M-SDF showed a shear thinning behavior. The latter showed stronger gelation ability at the presence of Ca 2+ evaluated by dynamic oscillatory rheometry. Moreover, M-SDF exhibited good abilities of binding bile acids in vitro. It could be concluded that M-SDF had a great potential to be applied as a novel kind of functional ingredient or additive in food industry.

A new heteropolysaccharide (PMH) with a molecular weight of 1.4 × 10 kDa was isolated from the seed husks of Plantago asiatica L. The monosaccharide composition of PMH was determined as glucose, xylose, arabinose, rhamnose, galactose and galacturonic acid with a molar ratio of 1.0 : 1.8 : 2.4 : 3.8 : 4.9 : 8.5. The backbone of PMH consisted of 1,4-β-d-GalpA with the side chains mainly composed of 1,3-α-d-Galp and 1,2-α-d-Galp which were attached to the O-3 of GlapA. The thermal analysis using the Flynn-Wall-Ozawa (FWO) method revealed that PMH had an apparent activation energy (E) of 173.1 kJ mol. PMH experienced a major decomposition during the heating process at a temperature of 91.1 °C with a dry weight loss of 31.1%. Moreover, PMH exhibited stronger antioxidant ability than commercial psyllium, partially due to its higher content of uronic acid. The results suggested that PMH could be used in functional foods due to its structural, thermal and antioxidant characteristics.