Preparation And Bioactivity Of Soluble Dietary Fiber In Plantago Asiatica L.

Plantago asiatica L is a perennial herb that grows mainly in JIAN area, Jiangxi province. Both the seed and the entire grass can be used as medicine. The chemical compositions of Plantago asiatica L are complex, in which the soluble dietary fiber is higher. The soluble dietary fiber has many kinds of physiological functions; it has good preventing and controlling effect to "rich illness" such as: diabetes, cardiovascular disease, obesity, intestinal cancer, constipation and so on. So it will have economic and social dual benefits by thorough study and the further development of soluble dietary fiber in Plantago asiatica L.The main research results obtained are outlined as follows:1. The content of soluble dietary fibre, insoluble dietary fibre and total dietary fibre in Jiangxi local Plantago asiatica L from different month were obtained by using the enzyme-weight method. The result showed that improved phenol-sulfuric acid method was suitable for determining the SDF content in Plantago asiatica L.2. The supersonic technology and orthogonal design L₉ (3⁴) were used to extract soluble dietary fibre in Plantago asiatica L. The test result indicated that the solid-liquid ratio was more remarkable to the result. These various factors to influence the extract result were in turns: solid-liquid ratio＞pH value＞extraction time; the best technological conditions were: the liquid-solid ratio was 1:30, extracting pH was 4, extraction time was 25min, under this condition the SDF extraction rate was78.4%, RSD=4.47%(n=3).3. Immerging Plantago asiatica L in hot water was a very easy way to extract soluble dietary fibre. The uniform design U₁₀ (10⁵) was used to optimize the extraction procedure, and the optimum technological conditions were: the extraction temperature,100℃; extraction time ,30min; solid-liquid ratio, 1:44; pH value, 6; extraction number of times; 2 times. 4. The High effective liquid phase chromatography method was used to determine the molecular weight of SDF in Plantago asiatica L. The result indicated that: the SDF mainly has two kinds of polysaccharide compositions, its molecular weight is: 1.81×10⁵ and 2.0×10⁶ respectively. The interception molecular weight of 100,000 ultra filter diaphragms was selected to intercept SDF from extraction water. The SDF was prepared by Ultra filters technology and the purity was up to 84.4%.5. The soluble dietary fiber of Plantago asiatica L has a high scavenging activity on·OH^- and·O₂^- free radical; the IC₅₀ was 4.61mg/mL, 8.34mg/mL respectively; It has certain scavenging action to DPPH, the highest percentage clearance was 13.7%. The lipid peroxidation experimem indicated that the SDF also can inhibit both the lipid auto-oxidation and peroxidation induced by Vc-Fe²⁺ system of old rate liver homogenate; the inhabitation and SDF density became relevance and IC₅₀ was3.91mg/mLand 2.14mg/mL respectively.6. The result of SDF adsorbed bile acid in vitro indicated that the SDF of Plantago asiatica L had certain adsorptive capacity to the bile acid and the adsorptive capacity was56mg/g, the returns-ratio of bile acid was 98.67±0.4(%),(n=3).7. The SDF prepared by ultra filters technology was high in its purity and can be used to develop high SDF healthy food directly; One kind of healthy food-granule was developed in this paper. The apparentness of the granule was hoariness and uniform. The granude was good in looseness, low absorption of moisture, the taste was sweet, and the SDF content was up to 22.6±4.2(%).