Study On Preparation And Lipid-lowering Ability Of Surface Deacetylated Konjac Glucomannan

Konjac is a plant with huge underground tubers in the Araceae family.As a Chinese herbal medicine,it has the effects of reducing swelling,detoxification,and anti-tumor.Konjac Glucomannan(KGM),which is rich in konjac,is different from cellulose which is a natural water-soluble dietary fiber.KGM has strong water absorption capacity.In addition,it has good biodegradability,biocompatibility,safety and non-toxicity,making konjac widely used in functional foods,health products,medicine and industry.This thesis synthesizes surface deacetylated konjac glucomannan particles(SDa-KGM)through a simple production process through alcohol and alkali,which not only maintains the original biodegradability of KGM,but also solves the problem that konjac glucomannan gels with water is difficult to take the human body.A series of adsorption experiments of SDa-KGM on cholesterol,free cholate sodium cholate and conjugated cholate sodium glycocholate were carried out in simulated in vitro adsorption experiments to study the lipid-lowering ability of SDa-KGM.In order to further comprehensively utilize konjac,in this paper,the conventional method was extracted boiled medicine Rhizoma Amorphophalli(konjac dried slices)active ingredient and analyzes the components of its higher content.This thesis has certain theoretical academic significance and application value for the development of konjac in functional foods and health care products,and the development of natural lipid-lowering drugs.The relevant experimental results are as follows:(1)Due to the deacetylation of SDa-KGM particles,the hydrogen bond between the molecules is strengthened to produce partial crystallization.The crystals are used as nodes to form a network structure on the surface of the particles and become water-insoluble or water-insoluble particles.The surface deacetylation experiment of KGM at room temperature showed that the swelling volume and structural factors of SDa-KGM particles in the solution were affected by the volume concentration of ethanol,the reaction time of deacetylation,and the weight ratio of Na OH to KGM.The swelling volume of SDa-KGM particles in the solution is directly proportional to the volume concentration of ethanol,and inversely proportional to the mass ratio of sodium hydroxide/KGM and the deacetylation time.(2)SDa-KGM simulated in vitro experiments to adsorb cholesterol,which is the representative of the three highs.The adsorption of cholesterol by SDa-KGM reached adsorption equilibrium at 90 min.As the initial concentration of cholesterol increased,the adsorption capacity of the three SDa-KGM particles for cholesterol first increased and then decreased slightly.The maximum adsorption capacities of SDa-KGM(30-2.4%-1),SDa-KGM(50-2.4%-1),and SDa-KGM(90-2.4%-1)are 83.1790 mg/g and 86.0690 mg/g,103.5189 mg/g respectively.The surface deacetylated konjac glucomannan has a strong adsorption capacity for cholesterol.The isotherm adsorption model and kinetic model of SDa-KGM for cholesterol adsorption fit the assumptions of Freundlich model and Lagergren quasi-second-order kinetic model respectively,indicating that the process of adsorption of cholesterol by SDa-KGM belongs to uneven surface adsorption.Moreover,the capacity of SDa-KGM to adsorb cholesterol is not only related to the concentration of the solution,but also controlled by the chemical adsorption mechanism,which has a certain relationship with the swelling volume of the particles in the solution and the degree of deacetylation.(3)Using ultraviolet spectrophotometry to determine the content of cholate,SDa-KGM in vitro simulated cholate adsorption experiments show that SDa-KGM has a faster adsorption rate for cholate,and its particles adsorb sodium cholate and sodium glycocholate to reach adsorption equilibrium at 40 min and 60 min,respectively.The adsorption capacity of SDa-KGM particles is proportional to the solution content of the adsorbate,and it changes greatly.When the concentration of the cholate solution is 0.5 mmol/L,the equilibrium adsorption capacities of SDa-KGM(90-2.4%-1)for sodium cholate and sodium glycocholate were 4.340 mg/g and 3.022 mg/g,respectively.Moreover,the adsorption models of SDa-KGM for cholate are closer to Freundlich isotherm model.It shows that the adsorption of cholate by SDa-KGM is also a non-monolayer adsorption model on a heterogeneous surface.From the experimental results,it can be seen that the adsorption capacity of SDa-KGM particles on free-type cholate sodium cholate is stronger than that of conjugated cholate sodium glycocholate.(4)The effective ingredients of the traditional Chinese medicine Rhizoma Amorphophalli were extracted with traditional alkaline water extraction,and the ingredients were identified.The aqueous extract of Rhizoma Amorphophalli was analyzed by liquid quality analysis,and 19 compounds were obtained,including water-soluble monosaccharides,8 acids,6 lipids,2 amides,and 2 heterocyclics.It shows that the water extract of Rhizoma Amorphophalli contains a lot of fatty acids and lipids.The concentration of Rhizoma Amorphophalli water-soluble polysaccharide in the water extract was 7.918 mg/mL.