响应曲面优化喜树生物碱醇提工艺研究

对喜树果中喜树碱的最佳醇提工艺条件进行了研究。采用乙醇浸提法,考查了乙醇浓度、液料比、提取温度及提取时间对喜树碱提取率的影响,经过一系列的单因素实验,结合响应曲面实验设计法及响应曲面分析(RSM),得到喜树碱的最佳提取工艺为:乙醇浓度88.53%,液料比21.4∶1(m L/g),时间2.23 h,提取温度40℃,经验证,在此提取工艺条件下,喜树碱提取率可达0.847 mg/g。     

莲子心总黄酮的超声波萃取工艺研究

研究了超声波萃取法从莲子心中提取总黄酮的最佳工艺。通过单因素控制法和正交试验,以乙醇为溶剂,总黄酮提取率为考察指标,在超声波辅助下研究了乙醇浓度、提取时间、料液比和提取温度对总黄酮提取率的影响。结果表明影响莲子心中总黄酮提取率的主要因素是乙醇的浓度,其次依次为提取温度、料液比、超声波萃取时间;提取的最佳条件是:乙醇的浓度为60%,提取温度是70℃,料液比为1:24,超声波萃取时间为30 min,此条件下得到的总黄酮的提取率是10.86 mg/g。     

响应面法优化余甘叶中黄酮提取工艺

以余甘叶为试材,利用超声波辅助提取余甘叶黄酮,研究料液比、乙醇浓度、超声时间、超声功率对黄酮提取率的影响,并在单因素试验的基础上,通过响应面分析法优化提取工艺。结果表明,余甘叶中黄酮最佳超声提取条件为：料液比1∶73、乙醇浓度50%、超声时间30 min、超声功率210 W,在此条件下黄酮实际提取率为19.51%。     

球面设计优化金线莲黄酮类物质提取工艺及糖耐受性的研究(英文)

以金线莲为材料,利用统计学实验设计方法对黄酮类物质的提取工艺进行了优化。选定液料比、乙醇浓度和时间三个因素的五个水平进行球面设计实验,建立黄酮提取率的二次回归方程,通过回归分析及岭脊分析得到优化提取组合条件。研究结果表明,当提取工艺条件为:液料比24,乙醇浓度63%,提取时间48 h时,黄酮提取率的最大预测值为1.107%,验证值为1.05%。葡萄糖耐受性试验结果表明:金线莲黄酮类萃取物能够提高正常小鼠对糖的耐受性。     

桑枝总黄酮的提取工艺研究

研究桑枝总黄酮的最佳提取工艺,本试验以桑枝（Tang10）为材料,以桑枝总黄酮得率为考察目标,采用二次回归正交旋转组合设计方法研究了提取温度、提取时间、乙醇浓度、料液比对桑枝总黄酮提取得率的影响,运用DPS软件对最佳工艺进行优化和验证。结果显示：试验范围内各因子对桑枝总黄酮提取率作用影响大小依次为提取温度〉料液比〉乙醇浓度〉提取时间;最佳提取参数为温度80℃,提取时间3．5h,乙醇浓度60％,料液比1：40部。因此,所建立数学回归模型在试验范围内能较准确的预测桑枝总黄酮的提取率．预测值与实测值相吻合,证明最佳工艺条件切实可行。     

响应面法优化乌骨藤通光藤苷G提取工艺

利用响应面法对乌骨藤Marsdenia tenacissima通光藤苷G的提取工艺进行优化。以通光藤苷G提取率为指标,在单因素试验的基础上,选取乙醇浓度、料液比、提取时间、提取次数进行4因素3水平的Box-Behnken中心组合研究,并运用Design Expect 8.0软件对试验参数进行分析,研究各自变量及其交互作用对通光藤苷G提取率的影响。结果显示,通光藤苷G的最佳提取条件为：乙醇溶液浓度80%,料液比1∶20(W/V),提取时间1.5 h,提取2次,在此条件下,通光藤苷G提取率为0.253%。     

玫瑰茄花色素的提取工艺研究

通过单因素和正交实验对玫瑰茄花色素提取工艺条件进行了比较筛选和优化。结果表明:玫瑰茄花色素提取的适宜溶剂为乙醇,适宜的酸碱度为p H 2.0;影响提取效果因素依次是提取时间、乙醇浓度、温度、料液比;最佳提取工艺条件为粉碎粒度40目、乙醇浓度70%(V∶V)、提取温度40℃、提取时间1.5 h、最佳料液比1∶20,在此优化条件下,玫瑰茄花色素的提取率可达0.485%。     

千年健总黄酮的超声提取工艺

为了研究千年健黄酮的超声提取工艺,通过单因素实验,研究了超声功率、超声时间、乙醇浓度、液固比等因素对黄酮得率的影响,利用正交试验对提取工艺进行优化。结果表明,各因素的影响次序为:超声功率乙醇浓度液固比超声时间,其最佳提取工艺条件为:超声功率为300W、超声时间15min、乙醇浓度50%、液固比30:1,最佳工艺条件下黄酮提取率为0.5868%。     

新疆紫花苜蓿单宁提取工艺优化探讨

目的:从新疆紫花苜蓿中提取单宁酸.方法:采用正交试验法研究新疆紫花苜蓿单宁酸的最佳提取工艺条件,考察了乙醇浓度、乙醇中盐酸的浓度、提取时间、及温度四因素对新疆紫花苜蓿单宁酸提取率的影响.结果:确立了新疆紫花苜蓿单宁酸最佳提取条件为:盐酸浓度2.5%,乙醇浓度70%,提取温度50℃,回流提取5h,在最佳提取工艺条件下,新疆紫花苜蓿中单宁提取量为2.15mg/g.     

余甘子总黄酮超声波辅助提取工艺的优化

以余甘子干粉为材料,利用超声波辅助提取余甘子总黄酮。单因素试验分析液料比、乙醇浓度、超声时间、超声功率对余甘子总黄酮提取率的影响,在此基础上,利用响应面分析法对提取工艺进行优化。结果表明,余甘子总黄酮最佳提取条件为：液料比82:1(V/W)、乙醇浓度45%、超声时间41 min、超声功率210 W,在此条件下余甘子总黄酮的实际提取率为6.12%。     

吉林长白山刺五加总皂苷超声提取工艺研究

以吉林长白山野生刺五加果实为原料,采用正交试验设计通过香草醛—高氯酸显色法对不同超声处理条件下刺五加果实粗提物中总皂甙得率进行测定,优化野生刺五加果实总皂甙超声提取工艺.结果表明:超声提取吉林长白山野生刺五加果实总皂甙的最佳工艺条件为料液比1∶20、乙醇体积分数70％、超声波功率450W、超声提取时间50 min,测得刺五加粗提物中总皂甙含量为3.57 mg/g,该提取方法简便、快捷,可用于长白山野生刺五加果实总皂甙提取和测定.     

Acid hydrolysis of sweet potato for ethanol production

Studies were conducted to establish optimal conditions for the acid hydrolysis of sweet potato for maximal ethanol yield. The starch contents of two sweet potato cultivars (Georgia Red and TG-4), based on fresh weight, were 21.1 +/- 0.6% and 27.5 +/- 1.6%, respectively. The results of acid hydrolysis experiments showed the following: (1) both hydrolysis rate and hydroxymethylfurfural (HMF) concentration were a function of HCL concentration, temperature, and time; (2) the reducing sugars were rapidly formed with elevated concentrations of HCl and temperature, but also destroyed quickly; and (3) HMF concentration increased significantly with the concentration of HCl, temperature, and hydrolysis time.Maximum reducing sugar value of 84.2 DE and 0.056% HMF (based on wet weight) was achieved after heating 8% SPS for 15 min in 1N HCl at 110 degrees C. Degraded 8% SPS (1N HCl, 97 degrees C for 20 min or 110 degrees C for 10 min) was utilized as substrate for ethanol fermentation and 3.8% ethanol (v/v) was produced from 1400 mL fermented wort. This is equal to 41.6 g ethanol (200 proof) from 400 g of fresh sweet potato tuber (Georgia Red) or an ethanol yield potential of 431 gal of 200-proof ethanol/acre (from 500 bushel tubers/acre).     

Combined microwave-assisted extraction and high-speed counter-current chromatography for separation and purification of xanthones from Garcinia mangostana

A microwave-assisted extraction (MAE) method is presented for the extraction of xanthones, α-mangostin and γ-mangostin from Garcinia mangostana. The MAE conditions including extraction temperature, liquid/solid ratio, extraction time and concentration of ethanol were optimized with an orthogonal test, and 5 g sample was extracted with the optimized conditions. The crude extraction of MAE was successfully isolated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (0.8:0.8:1:0.6, v/v) in one-step separation. The separation yielded 75 mg of α-mangostin at 98.5% purity, and 16 mg of γ-mangostin at 98.1% purity from 360 mg crude extract of G. mangostana in less than 7h. The purity of the two xanthones was determined by HPLC. Their structures were further identified by ESI-MS, (1)H NMR and (13)C NMR.     

The use of tamarind waste to improve ethanol production from cane molasses

Tamarind wastes such as tamarind husk, pulp, seeds, fruit and the effluent generated during tartaric acid extraction were used as supplements to evaluate their effects on alcohol production from cane molasses using yeast cultures. Small amounts of these additives enhanced the rate of ethanol production in batch fermentations. Tamarind fruit increased ethanol production (9.7%, w/v) from 22.5% reducing sugars of molasses as compared to 6.5% (w/v) in control experiments lacking supplements after 72 h of fermentation. In general, the addition of tamarind supplements to the fermentation medium showed more than 40% improvement in ethanol production using higher cane molasses sugar concentrations. The direct fermentation of aqueous tamarind effluent also yielded 3.25% (w/v) ethanol, suggesting its possible use as a diluent in molasses fermentations. This is the first report, to our knowledge, in which tamarind-based waste products were used in ethanol production. Received 2 April 1998/ Accepted in revised form 13 November 1998     

Box-Behnken响应面法优化超声波辅助提取辣木叶多酚工艺研究

采用超声波辅助提取辣木Moringa oleifera叶多酚,通过单因素试验考察乙醇浓度、料液比、提取时间和提取次数对辣木叶多酚得率的影响,进一步利用四因素三水平Box-Behnken组合设计响应面试验对提取工艺参数进行优化。结果表明,超声波辅助提取辣木叶多酚的最佳工艺条件为乙醇浓度62%、料液比1∶30(W/V)、提取时间30 min、提取3次,在此条件下辣木叶多酚得率为27.32 mg·g-1,所得回归模型拟合情况良好。     

Ethanol fermentation in an immobilized cell reactor using Saccharomyces cerevisiae

Fermentation of sugar by Saccharomyces cerevisiae, for production of ethanol in an immobilized cell reactor (ICR) was successfully carried out to improve the performance of the fermentation process. The fermentation set-up was comprised of a column packed with beads of immobilized cells. The immobilization of S. cerevisiae was simply performed by the enriched cells cultured media harvested at exponential growth phase. The fixed cell loaded ICR was carried out at initial stage of operation and the cell was entrapped by calcium alginate. The production of ethanol was steady after 24 h of operation. The concentration of ethanol was affected by the media flow rates and residence time distribution from 2 to 7 h. In addition, batch fermentation was carried out with 50 g/l glucose concentration. Subsequently, the ethanol productions and the reactor productivities of batch fermentation and immobilized cells were compared. In batch fermentation, sugar consumption and ethanol production obtained were 99.6% and 12.5% v/v after 27 h while in the ICR, 88.2% and 16.7% v/v were obtained with 6 h retention time. Nearly 5% ethanol production was achieved with high glucose concentration (150 g/l) at 6 h retention time. A yield of 38% was obtained with 150 g/l glucose. The yield was improved approximately 27% on ICR and a 24 h fermentation time was reduced to 7 h. The cell growth rate was based on the Monod rate equation. The kinetic constants (K(s) and mu(m)) of batch fermentation were 2.3 g/l and 0.35 g/lh, respectively. The maximum yield of biomass on substrate (Y(X-S)) and the maximum yield of product on substrate (Y(P-S)) in batch fermentations were 50.8% and 31.2% respectively. Productivity of the ICR were 1.3, 2.3, and 2.8 g/lh for 25, 35, 50 g/l of glucose concentration, respectively. The productivity of ethanol in batch fermentation with 50 g/l glucose was calculated as 0.29 g/lh. Maximum production of ethanol in ICR when compared to batch reactor has shown to increase approximately 10-fold. The performance of the two reactors was compared and a respective rate model was proposed. The present research has shown that high sugar concentration (150 g/l) in the ICR column was successfully converted to ethanol. The achieved results in ICR with high substrate concentration are promising for scale up operation. The proposed model can be used to design a lager scale ICR column for production of high ethanol concentration.     

Optimization of extraction process by response surface methodology and preliminary structural analysis of polysaccharides from defatted peanut (Arachis hypogaea) cakes

In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from defatted peanut cake. A central composite design including independent variables, such as extraction temperature (x₁), extraction time (x₂), and ethanol concentration (x₃) was used. Selected response which evaluates the extraction process was polysaccharide yield, and the second-order model obtained for polysaccharide yield revealed coefficient of determination of 97.81%. The independent variable with the largest effect on response was ethanol concentration (x₃). The optimum extraction conditions were found to be extraction temperature 48.7 °C, extraction time 1.52 h, and ethanol concentration of 61.9% (v/v), respectively. Under these conditions, the extraction efficiency of polysaccharide can increase to 25.89%. The results of structural analysis showed that the main composition of defatted peanut cake polysaccharide was α-galactose.     

Yellow Mealworm Protein for Food Purposes - Extraction and Functional Properties

A protocol for extraction of yellow mealworm larvae proteins was established, conditions were evaluated and the resulting protein extract was characterised. The freeze-dried yellow mealworm larvae contained around 33% fat, 51% crude protein and 43% true protein on a dry matter basis. The true protein content of the protein extract was about 75%, with an extraction rate of 70% under optimised extraction conditions using 0.25 M NaOH, a NaOH solution:ethanol defatted worm ratio of 15:1 mL/g, 40°C for 1 h and extraction twice. The protein extract was a good source of essential amino acids. The lowest protein solubility in distilled water solution was found between pH 4 and 5, and increased with either increasing or decreasing pH. Lower solubility was observed in 0.5 M NaCl solution compared with distilled water. The rheological tests indicated that temperature, sample concentration, addition of salt and enzyme, incubation time and pH alterations influenced the elastic modulus of yellow mealworm protein extract (YMPE). These results demonstrate that the functional properties of YMPE can be modified for different food applications.     

Production of fuel ethanol at high temperature from sugar cane juice by a newly isolated Kluyveromyces marxianus

Kluyveromyces marxianus DMKU 3-1042, isolated by an enrichment technique in a sugar cane juice medium supplemented with 4% (w/v) ethanol at 35 degrees C, produced high concentrations of ethanol at both 40 and 45 degrees C. Ethanol production by this strain in shaking flask cultivation in sugar cane juice media at 37 degrees C was highest in a medium containing 22% total sugars, 0.05% (NH(4))(2)SO(4), 0.05% KH(2)PO(4), and 0.15% MgSO(4).7H(2)O and having a pH of 5.0; the ethanol concentration reached 8.7% (w/v), productivity 1.45 g/l/h and yield 77.5% of theoretical yield. At 40 degrees C, a maximal ethanol concentration of 6.78% (w/v), a productivity of 1.13 and a yield 60.4% of theoretical yield were obtained from the same medium, except that the pH was adjusted to 5.5. In a study on ethanol production in a 5l jar fermenter with an agitation speed of 300 rpm and an aeration rate of 0.2 vvm throughout the fermentation, K. marxianus DMKU 3-1042 yielded a final ethanol concentration of 6.43% (w/v), a productivity of 1.3g/l/h and a yield of 57.1% of theoretical yield.     

Preparation of the particles of Acanthopanax senticosus

The main objective of this study is to establish the best preparation technology of the particles of Acanthopanax senticosus. First, take the reflux extraction method extract of Acanthopanax senticosus coarse powder, optimized by orthogonal experimental method, to flavonoids flavonoids extraction extraction rate as the indexes to determine the effects of extraction temperature, ethanol concentration, extraction time on flavonoids content. Then by a wet granulation of thorn slender acanthopanax particles, taste with granules, forming rate, melting rate as index to investigate the influences of materials adding amount of granules effect. The results showed that the ethanol water heating reflux extraction method to extract the temperature of 70 deg, the percentage of ethanol 75%, extraction time 2.5 h, the highest content of total flavonoids in the extract. Join the 5 ml and 10 g in the extract of acacia honey, dextrin, starch, sugar ratio for 3:4:8, the best taste of Acanthopanax granules. In the end, the best preparation technology of the granules is established, and the process is simple, which is suitable for the large-scale production of the factory.