响应面法优化黄参多糖的提取工艺及其体外抗氧化活性

探讨常规热水法提取黄参多糖的最佳工艺并研究了黄参多糖的生物活性。在单因素实验的基础上,采用响应面法对黄参多糖的提取工艺参数进行优化。响应面实验表明,提取时间、温度以及料液比对响应值黄参多糖提取率均有显著的影响,优化得到常规热水法提取黄参多糖的最佳工艺条件为:时间5.45 h,温度为75℃,料液比为1∶34(g/m L),提取3次,在此条件下多糖得率为12.52%。通过考察黄参多糖对DPPH自由基、·OH自由基和超氧阴离子自由基的清除能力以及对亚铁离子螯合作用和还原力,结果表明,黄参多糖具有良好的抗氧化活性,值得进一步关注和对其进行深入研究。     

少花龙葵茎总黄酮提取工艺及其抗氧化性研究

采用乙醇浸提法对Solanum photeinocar pum茎总黄酮的提取工艺及其抗氧化性能进行了研究,探讨了溶剂浓度、温度、提取时间、料液比等因素对总黄酮含量提取的影响,并采用正交实验对提取工艺进行优化。结果表明,最佳提取工艺参数乙醇浓度为40%,提取温度为80℃,时间为1h,料液比1:16(g:mL)。在此条件下测得总黄酮含量为4.39mg/g,提取物对羟自由基具有较好的清除效果。     

若羌大枣多糖提取及分离工艺研究

目的：确定大枣多糖提取分离工艺的参数。方法：采用热水浸提法取多糖,乙醇沉淀法分离多糖。对液固比、浸提时间、浸提温度进行了单因素和L9（3^3）正交实验,并对提取过程中影响提取率的因素进行了统计分析。对多糖浸提液浓缩倍数、乙醇沉淀体积、醇沉时间对大枣多糖得率的影响进行了研究。结果：最佳提取工艺条件为：提取时间6h,料水比1：24,提取温度90℃。最佳分离工艺：浓缩倍数为8倍,4倍体积乙醇,醇沉12h,大枣多糖的得率最大。结论：实验结果为新疆次级大枣的深加工提供了可参数据。     

广东石豆兰多糖的提取工艺及其抗氧化活性

为优化广东石豆兰多糖的提取工艺并评价其抗氧化活性。在单因素试验基础上,采用正交设计和方差分析,研究液料比、提取温度、时间及沉淀多糖的乙醇浓度对石豆兰多糖浸提量的影响并优化了工艺条件,确定最优条件为液料比50∶1 (mL/g),提取温度90℃,时间6 h,醇沉浓度为95%,此条件下多糖提取量为79.060 mg/g,RSD为0.132%。抗氧化结果表明广东石豆兰多糖的总还原力为L-抗坏血酸的3.46%;对DPPH、·OH、·O■自由基半清除浓度(EC₅₀)分别为2769.58、594.60、586.94μg/mL,其清除能力分别是L-抗坏血酸的0.68%、47.17%和29.00%;对Fe²⁺的半螯合浓度(EC₅₀)为160.83μg/mL,螯合能力是EDTA的2.12%。本研究结果为石豆兰多糖的提取及进一步开发利用提供参考依据。     

超临界CO_2流体萃取苦丁茶多糖的工艺优化

为了探讨超临界CO_2萃取广西苦丁茶中多糖的工艺条件,该研究采用超临界CO_2流体萃取技术分离苦丁茶多糖,利用苯酚-硫酸法对苦丁茶多糖含量进行测定,并考察不同萃取温度(35、40、45、50、55、60℃)、萃取压力(20、25、30、35、40、45、50 MPa)、萃取时间(30、60、90、120、150 min)、夹带剂(甲醇、95%甲醇、50%甲醇、无水乙醇、95%乙醇、50%乙醇)以及夹带剂(95%乙醇)用量(2.0、2.5、3、3.5、4.0、4.5、5.0 mL·min~(-1))对多糖得率的影响,通过设计正交实验方案,对超临界CO_2萃取广西苦丁茶多糖的提取工艺进行优化。结果表明:通过单因素和正交实验考察了苦丁茶多糖提取的主要影响因素,得到的最佳萃取工艺条件为萃取温度50℃,萃取压力40 MPa,夹带剂流量3.5 mL·min~(-1),萃取时间150 min;采用苯酚-硫酸法对苦丁茶多糖含量进行测定。在最优萃取条件下得到的苦丁茶多糖的提取率为7.05%。由此可知,采用超临界CO_2流体萃取,具有提取温度低、萃取率高、萃取周期短、低耗以及污染小等优点,适用于苦丁茶多糖的提取。     

变色疣柄牛肝菌子实体水溶性粗多糖的提取方法

试验就变色疣柄牛肝菌多糖的提取方法进行了初浅探索,结果表明变色疣柄牛肝菌干燥子实体萃取粗多糖较佳的条件为:粒度以粉碎60目筛、提取剂为蒸馏水、选择菌盖、选择料水比为1∶35(W/V)、沉淀剂达到85%的乙醇浓度、萃取温度选择在80℃、萃取时间为3 h、提取2次可得到粗多糖3%~5%。正交试验表明影响变色疣柄牛肝菌多糖得率的主次因素为乙醇浓度、提取温度、提取时间、料水比,各因素的最佳配合、最优工艺为A3B2C1D3,即乙醇浓度为85%、温度80℃、时间3 h、料水比为1∶15,在此条件下多糖得率为5.008%,提取粗多糖含量在47.995%。     

野生黄精的多糖含量测定及提取工艺研究

采用3,5-二硝基水杨酸法(DNS法)测定了宁波四明山区野生黄精的多糖含量,并对水煎煮法提取黄精多糖的工艺进行优化。通过单因素实验获得了提取温度、提取时间、液料比对黄精多糖得率的影响;在单因素实验的基础上采用L_9(3~4)正交试验优化黄精多糖提取工艺。研究结果表明,宁波野生黄精多糖的含量为25.09%;各因素对黄精多糖得率的影响不同,液料比对黄精多糖得率的影响最大,其次是提取温度和提取时间。黄精多糖最佳提取工艺为:提取温度为80℃,提取时间为2 h,液料比为20∶1,在该条件下,黄精多糖得率为27.43%。为黄精多糖的开发利用奠定了理论基础。     

响应面法优化玫瑰茄粗多糖提取工艺及其抗氧化活性的研究

利用响应面法优化玫瑰茄粗多糖的提取工艺条件,测定粗多糖的抗氧化活性。按照Box-Behnken中心组合试验设计原理,以玫瑰茄粗多糖的得率为响应值,在单因素试验的基础上,进行响应面分析试验,考察料液比、提取时间和提取温度对得率的影响。玫瑰茄粗多糖最佳提取工艺条件为：料液比1∶26 (g/mL)、提取时间3.1 h、提取温度90℃,在该最优条件下所得玫瑰茄粗多糖的得率为14.41%,与预测值接近;玫瑰茄粗多糖对DPPH、羟基、超氧阴离子自由基具有一定的清除作用。研究结果为玫瑰茄粗多糖的研究、开发和利用提供了理论基础。     

裂蹄木层孔菌多糖的提取工艺及抗氧化活性研究

以多糖提取率为检测指标,采用水提醇沉法提取裂蹄木层孔菌多糖。正交实验考察提取温度、提取时间和料液比对多糖提取率的影响。结果显示,提取温度和料液比对多糖提取率有显著性影响,提取时间对多糖提取率无显著性影响。最佳提取工艺为提取温度80℃、提取时间2 h、料液比1∶40(g/m L)。在此条件下,多糖平均提取率为3.20%。选用终体积分数70%的乙醇沉淀多糖12 h时,多糖得率最高。体外抗氧化活性实验结果显示,裂蹄木层孔菌多糖的总抗氧化能力、清除羟自由基和超氧阴离子自由基的能力在实验范围内随着多糖质量浓度的增加而增强。裂蹄木层孔菌多糖是一种具有抗氧化功能的药用真菌多糖。     

羊肚菌多糖提取及其抗氧化活性研究

为了探讨碱法提取羊肚菌多糖的工艺条件并测定其抗氧化活性,该研究以四川北川羊肚菌为原料,采用碱法提取羊肚菌多糖,利用苯酚-硫酸法对羊肚菌多糖得率进行测定,并通过单因素探讨提取温度(70、80、90、100℃)、提取时间(2、4、6、8 h)、碱液浓度(0.4、0.6、0.8、1.0 mol·L~(-1))、料液比(1∶15、1∶20、1∶25、1∶30 g·mL~(-1))对羊肚菌多糖得率的影响,同时采用正交试验优化提取工艺,对其抗氧化活性进行测定。结果表明:在提取温度90℃、提取时间5 h、碱液浓度0.7 mol·L~(-1)、料液比1∶20(g·mL~(-1))条件下得到的羊肚菌多糖得率为5.39%。羊肚菌多糖具有较强的清除DPPH自由基、羟自由基、超氧阴离子的能力和较好的还原能力,其IC50分别为0.468、0.208、0.022、0.014 mg·mL~(-1),抗氧化能力依次为还原能力超氧阴离子清除能力羟自由基清除能力DPPH自由基清除能力。优化后的羊肚菌多糖提取工艺合理、可行,且羊肚菌多糖具有较强的抗氧化活性。     

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.     

酶法脱蛋白提取大枣多糖工艺的研究

讨论了从提取环磷酸腺苷后的枣汁中提取枣多糖的最佳工艺条件,包括枣汁浓缩4倍,加无水乙醇调枣汁中乙醇体积分数为60%,醇沉5 h;木瓜蛋白酶脱蛋白效果最佳,木瓜蛋白酶液与枣汁的体积比为0.4∶ 1,温度60℃、pH5.0,酶解90 min,蛋白脱除率可达91.8%;AB-8树脂脱色,脱色率为73.64%,多糖得率为94.4%.红外光谱显示,提取的多糖与常规方法提取的多糖成分相同.     

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).     

Application of a biosensor for monitoring of ethanol

An alcohol biosensor for the measurement of ethanol has been developed. It comprises an alcohol oxidase/chitosan immobilized eggshell membrane and a commercial oxygen sensor. Ethanol determination is based on the depletion of dissolved oxygen content upon exposure to ethanol solution. The decrease in oxygen level was monitored and related to the ethanol concentration. The biosensor response depends linearly on ethanol concentration between 60 microM and 0.80 mM with a detection limit of 30 microM (S/N=3) and 1 min response time. In the optimization studies of the enzyme biosensor the most suitable enzyme and chitosan amounts were found to be 1.0 mg and 0.30% (w/v), respectively. The phosphate buffer (pH 7.4, 25 mM) and room temperature (20-25 degrees C) were chosen as the optimum working conditions. In the characterization studies of the ethanol biosensor some parameters such as interference effects, operational and storage stability were studied in detail. The biosensor was also tested with various wine samples. The results of this newly developed biosensor were comparable to the results obtained by a gas chromatographic method.     

响应面法优化Zn-Mn-Co/HZSM-5催化乙醇脱水制乙烯

采用响应面法研究温度、乙醇浓度、质量空速对锌、锰、钴改性的HZSM-5催化乙醇脱水制备乙烯过程中乙烯收率的影响。结果表明反应温度对乙烯收率影响最大,并且各因素之间存在交互作用。用响应面方法确定乙醇脱水制备乙烯的最佳工艺条件是：温度261.3 ℃,乙醇浓度34.4％,质量空速1.18 h?1,在该条件下乙烯收率达到98.69％。     

Optimization of antibacterial activity by Gold-Thread (Coptidis Rhizoma Franch) against Streptococcus mutans using evolutionary operation-factorial design technique

This study was conducted to find the optimum extraction condition of Gold-Thread for antibacterial activity against Streptococcus mutans using The evolutionary operation-factorial design technique. Higher antibacterial activity was achieved in a higher extraction temperature (R2 = -0.79) and in a longer extraction time (R2 = -0.71). Antibacterial activity was not affected by differentiation of the ethanol concentration in the extraction solvent (R2 = -0.12). The maximum antibacterial activity of clove against S. mutans determined by the EVOP-factorial technique was obtained at 80 degrees C extraction temperature, 26 h extraction time, and 50% ethanol concentration. The population of S. mutans decreased from 6.110 logCFU/ml in the initial set to 4.125 logCFU/ml in the third set.     

Optimization of fermentation conditions for the production of ethanol from sago starch using response surface methodology

The quantitative effects of temperature, pH and time of fermentation were investigated on simultaneous saccharification and fermentation (SSF) of ethanol from sago starch with glucoamylase (AMG) and Zymomonas mobilis ZM4 using a Box–Wilson central composite design protocol. The SSF process was studied using free enzyme and free cells and it was found that with sago starch, maximum ethanol concentration of 70.68 g/l was obtained using a starch concentration of 140 g/l, which represents an ethanol yield of 97.08%. The optimum conditions for the above yield were found to be a temperature of 36.74 °C, pH of 5.02 and time of fermentation of 17 h. Thus by using the central composite design, it is possible to determine the accurate values of the fermentation parameters where maximum production of ethanol occurs.     

Optimization of medium constituents and fermentation conditions for the production of ethanol from palmyra jaggery using response surface methodology

The quantitative effects of sugar concentration, nitrogen concentration, EDTA, temperature, pH and time of fermentation on ethanol production were optimized using a Box-Wilson central composite design (CCD) experiment. It was found that palmyra jaggery (sugar syrup from the palmyra palm) is a suitable substrate for the production of high concentrations of ethanol using Saccharomyces cerevisiae NCIM 3090 by submerged fermentation. A maximum ethanol concentration of 129.4 g/l was obtained after optimizing media components and conditions of fermentation. The optimum values were a temperature of 26.2 °C, pH of 8.4, time of fermentation of 4.2 days with 398.5 g of substrate/l, 3.1 g of urea/l and 0.51 g of EDTA/l. Thus by using the CCD, it is possible to determine the accurate values of the fermentation parameters where maximum production of ethanol occurs.     

酶法提取桑葚多糖的工艺研究

利用纤维素酶从桑葚中提取桑葚多糖,通过单因素实验和L9(34)正交实验研究酶用量、酶解时间、酶解温度对桑葚多糖提取率的影响。实验结果表明:纤维素酶能够显著提高桑椹多糖的提取率,并且提取温度是最重要的影响因素,其次是酶解时间,酶用量在此实验范围内对测定结果的影响最小,提取的最佳工艺条件为:酶解温度45℃,酶解时间150 min,酶用量4.0 mL。