Study On The Extraction And Separation Process Of Effective Components From Fenugreek And Its Application

Fenugreek (Trigonella foenum graecum L.) is an annual herbaceous plant from the family of Leguminosae. Fenugreek has long been known as a traditional food and medicine, which are assumed to have restorative and nutritive properties. Fenugreek seeds have components of galactomannan gum, protein, fatty acid, dioscin and pigment. At present, the fenugreek gum has been used broadly in petroleum exploitation, food and curatorial-chemical industry, while the other effective components have not been used sufficiently. The objective of present study is to develop the comprehensive utilization of fenugreek seeds. For this purpose, the remainder of fenugreek seeds separated fenugreek gum is the raw material of this study. The extraction and separation technology of effective components from fenugreek was investigated and the synthetic method of steroid hormone drugs with diosgenin had been studied also.Firstly, seven processing methods were compared to extract diosgenin from fenugreek. The results showed that pre-soaking-ultrasound extraction was the optimal method. Experiment factors and levels were firstly selected by one-factor tests. According to the central composite experimental design, the Response Surface Methodology with 4 factors and 5 levels was adopted. The factors influencing the technological parameters were determined by means of regression analysis. Under the optimization conditions, the extraction rate could be up to 87%. The product was analyzed and confirmed by HPLC analysis and IR spectrum respectively. Compared with present extraction technology, pre-soaking-ultrasound technology had the advantages of higher extraction rate and higher purity of product. In addition, the fatty acid components extracted from fenugreek were analyzed. It was found that the content of unsaturated fatty acid was higher than that of saturated fatty acid. The relative content of unsaturated fatty acid was more than 80%, of which oleic acid, linolenic acid and linoleic acid were main components. The results provide the basis for its exploitation and utilization.Secondly, the separation and purification technology for saponins from aqueous solution by the way of clarificant combined with macroporous resin was studied. Functional performance tests of modified bentonite, ZTC1+1 clarify agent, chitosan flocculant and traditional ethanol disposal method were studied. It indicated that modified bentonite was fit for the system. Including AB-8,XDA-1,HPD400A macroporous resin, eleven kinds of resins were selected to compare their absorbing and desorbing capacity of saponins from aqueous solution. HPD400A was considered as the optimal macroporous resin for the adsorption of saponins. HPD400A in aqueous was investigated in static experiments. The data obtained from kinetic and isotherm experiments could be well described by pseudo-second-order rate model and Freundlich isotherm model respectively. The velocity of flowing adsorption and the leak carve were determined by dynamic experiments. The content of saponins in raw extract increased from 11.38% to 42.75% after purification.Thirdly, yellow pigment was extracted from fenugreek. Based on the results of single factor experiments and orthogonal experiments, the optimal processing parameter was obtained. The pigment was confirmed to be flavonoid by using method of UV spectrum and color reactions. Experiments were carried out to study its physical and chemical properties. The effects of different pH values, metal ions, light, heat, oxidants, reductants and common food additives on the stability of the pigment were studied. The results show that the pigment could resist heat, sunlight and oxygenation. The pigment is stable in acidic environment, but sensitive to basic environment. Most food additives and most metal ions do not show deteriorative effects on the pigment except sodium benzoate. It indicates that the pigment has good stability.Finally, the synthesis of 16-dehydropregnenolone acetate (16-DPA) was investigated with diosgenin of fenugreek as raw material. 16-DPA was synthesized by three steps reaction including acetolysis, oxidation and hydrolysis. HPLC quantitative analysis method was exploited to analysis the intermediate product pseudodiosgenin diacetate and 16-DPA.Using phosphotungstic acid supported on silica molecular sieve as catalyst; hydroperoxide was used as environmentally friendly and benign oxidizing agent to accomplish the oxidation reaction efficiently instead of environmentally toxic chromium oxidant. The optimal parameters of the synthesis of 16-DPA had been obtained via the single factor experiments and uniform design method. The results showed that the yield of 16-DPA was about 63.38%. The catalyst and 16-DPA were analyzed and characterized by IR, XRD, TGA-SDTA, HPLC method respectively.