【作者】 唐璇；

【导师】 李稳宏；

【作者基本信息】 西北大学 ， 化学工程， 2008， 博士

【摘要】 胡芦巴为一年生豆科草本植物,具有营养、滋补的功效,一直以来被作为药食同源之品。胡芦巴种子含有一定量的半乳甘露聚糖胶以及薯蓣皂苷、油脂、色素等有效成分。目前半乳甘露聚糖胶已被广泛应用于石油开采、食品、医药化工等行业,而脱半乳甘露聚糖胶后胡芦巴渣中其他成分基本未加利用,造成资源浪费。针对以上社会上迫切需要解决的现实问题,本课题系统地开展了从脱胶后胡芦巴渣中有效成分提取及其下游产品合成研究。以期达到对植物胡芦巴进行资源化综合利用并提高经济效益的目的。首先对从胡芦巴渣中提取薯蓣皂苷元的七种工艺路线进行了系统的对比研究,在筛选出最为理想的超声波提取工艺路线基础上,通过对比研究了五种超声波不同组合工艺,得到了优化的提取工艺路线:预浸泡-超声法提取工艺。在单因素实验基础上,通过响应面设计和回归分析得到了预浸泡-超声法优化的工艺操作参数。对优化工艺条件下得到的薯蓣皂苷元产品进行了分析及表征。结果表明:优化工艺的提取率优于现有工艺,达87%,且所得产品纯度较高。此外对在原料预处理阶段所得胡芦巴油脂进行了成分分析,结果表明脱胶胡芦渣巴中不饱和脂肪酸几乎占脂肪酸总量80%以上,为进一步合理开发胡芦巴油脂提供了科学依据。采用吸附澄清法与大孔吸附树脂吸附法联合工艺对胡芦巴超声波水提取液中的总皂苷进行分离纯化。以改性膨润土为澄清剂,对其工艺参数进行了优化。通过对改性膨润土、壳聚糖、ZTC1+1等不同澄清工艺以及传统醇沉工艺的对比研究,表明改性膨润土对于该体系的澄清效果较好。通过对AB-8、XDA-1、HPD400A等10余种大孔吸附树脂对胡芦巴总皂苷吸附及解吸性能的比较,确定了具有良好吸附和洗脱性能的树脂类型。研究了静态吸附条件下胡芦巴总皂苷在大孔树脂上的吸附动力学、热力学以及动态吸附条件下的不同流速的穿透曲线方程,为该技术进一步工业化提供了一定的依据。通过以上分离纯化处理,粗提物中的总皂苷含量可由11.38%提高到42.75%。对胡芦巴渣中提取黄色素工艺进行了研究,在单因素基础上通过正交实验得到了优化工艺操作参数。对胡芦巴黄色素稳定性进行系统研究。通过紫外光谱和显色反应等方法可确定该色素属于黄酮类化合物。研究表明胡芦巴中黄色素耐光性、耐热性均较好。在酸性条件下稳定性较好,碱性环境对其有破坏作用;抗氧化性较好,抗还原性较差。常见食品添加剂(除苯甲酸钠外)和金属离子对色素无显著影响。以上研究结果表明此胡芦巴色素具有较好的稳定性,具有深入开发研究的价值。开展了以胡芦巴渣中提取的薯蓣皂苷元为原料合成双烯醇酮醋酸酯(简称双烯)的研究。分别对合成过程中的开环、氧化及水解消除反应工艺过程以及工艺参数进行了优化研究,采用高效液相色谱对中间产物和产品双烯进行定量分析。考虑到现有氧化工艺中氧化剂铬酐造成严重环境污染的问题,制备了负载型固体杂多酸催化剂,研究了以过氧化氢为氧化剂催化氧化制备双烯环境友好的“绿色”工艺,采用均匀设计的方法对氧化工艺参数进行优化;在优化工艺条件下双烯的收率为63.38%。采用红外光谱(IR)、X射线粉末衍射(XRD)、热重-差热(TGA-SDTA)、高效液相色谱(HPLC)等分析手段对催化剂及合成的双烯产品进行了分析及表征。以上研究结果为胡芦巴资源的综合利用提供了有效途径,具有较好的经济、社会价值以及应用前景。更多还原

【Abstract】 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.更多还原