回流法提取银杏叶总黄酮的研究

研究了乙醇回流法提取银杏叶总黄酮的工艺条件。通过单因素实验考察料液比、乙醇体积分数、提取时间、提取温度对银杏叶总黄酮提取率的影响,通过正交实验确定优化的提取工艺条件为:料液比1∶45(g∶mL)、乙醇体积分数50%、提取时间2.0h、提取温度70℃,在此条件下,银杏叶总黄酮提取率为0.918%。以优化的工艺条件为基础进一步运用微波辅助提取银杏叶总黄酮,发现在微波功率为640W时,采用间歇式提取,提取时间为15×10s,总黄酮提取率达到0.91%,接近传统方法提取3h的提取率。     

微波辅助提取党参皂甙工艺研究

本文以烘干恒重的党参粉末为原料,研究微波提取法和乙醇浸提法的提取工艺和影响因素,并将这两种优化工艺条件进行比较。这两种方法都是以乙醇作为提取溶剂,分别研究溶剂浓度、液固比、提取时间、乙醇浸提的提取温度或微波提取的微波功率对党参皂甙提取率的影响。结果表明,微波提取法中4个因素影响党参皂甙提取率的主次顺序为乙醇浓度加热时间液固比微波功率,此方法的最佳提取工艺条件为:乙醇浓度为70%,液固比为80mL.g-1,提取时间为10×20s,微波功率为320W,皂甙提取率为3.15%。乙醇浸提法中4个因素影响党参皂甙提取率的主次顺序为乙醇浓度液固比加热时间提取温度,此方法的最佳提取工艺条件优化条件为:乙醇浓度为70%,液固比80mL.g-1,加热时间为80min,提取温度70℃,提取率为2.17%。结果证明,微波提取党参皂甙具有简便快速、高效节能、重复性好的优点。     

微波辅助提取牡丹雄蕊总生物碱工艺研究

采用微波辅助法提取牡丹雄蕊中的总生物碱。考察了料液比、浸润时间、微波加热提取时间、微波功率、pH值和乙醇浓度等对提取率的影响。结果表明,牡丹雄蕊总生物碱的最佳提取工艺条件为:料液比1∶20,浸润时间24 h,微波加热提取时间15 min,微波功率500 W,pH值3和乙醇浓度80%。在此最佳工艺条件下,牡丹雄蕊中总生物碱提取率为2.16%。     

微波辅助提取竹叶黄酮的研究

用微波辐射技术辅助乙醇提取竹叶总黄酮的结果表明,微波辅助萃取的最佳工艺条件为:固液比为1∶25(w/w),溶剂乙醇的体积分数为60%,微波功率为600 W,辐射时间为6 min。在此条件下,竹叶中的总黄酮提取率可达2.93%。     

微波提取苹果渣中总黄酮的工艺研究

采用微波辐射技术,以乙醇提取苹果渣中黄酮类化合物。考察了乙醇浓度、微波功率、处理时间、料液比和浸泡时间对总黄酮提取率的影响。结果表明,最佳工艺条件为:70%乙醇,微波萃取2 min,微波功率为350 W,料液比1∶30(g/mL),总黄酮1次提取率0.683 7%。     

微波辅助提取松针中莽草酸的工艺研究

研究了微波辅助提取松针中莽草酸的提取工艺,考察了微波温度、料液比、微波功率、乙醇浓度和微波时间等因素对莽草酸提取率的影响,通过正交试验优化了提取工艺。结果表明,松针中莽草酸提取的最佳工艺条件为:微波温度35℃,料液比1∶20(g/mL),微波功率550W,乙醇浓度35%,微波时间90s,在此条件下,莽草酸的提取率可达11.312mg/g。     

银杏叶总黄酮的提取及其抗氧化性的研究

采取微波辅助乙醇法提取银杏叶总黄酮,探讨最佳提取条件及产品的抗氧化性活性。研究表明,提取的影响因素顺序为乙醇浓度>固液比>微波时间>微波功率,最佳工艺条件为:乙醇浓度90%,固液比1∶40(g/mL),微波时间20 min,微波功率600 W。抗氧化的实验表明,银杏叶黄酮提取物对超氧阴离子、羟自由基和DPPH自由基均有较强的清除作用,且随着添加量的增大而增强。同浓度的银杏提取物比同浓度的Vc溶液清除效果好。     

微波法提取薏苡仁油的研究

以薏苡仁油的提取率为指标,考察了微波法提取薏苡仁油的主要影响因素微波辐射功率、微波辐射时间、料液比和药材粒度;采用气相色谱法考察微波对薏苡仁油成分的影响,并与加热回流法进行了比较.结果表明,微波法提取薏苡仁油的优化工艺条件为:采用无水乙醇作溶剂、药材粒度60目、微波辐射功率300 W、微波辐射时间7 min、料液比1∶5,在此条件下薏苡仁油的提取率为6.87%;气相色谱分析表明,微波法与加热回流法提取的薏苡仁油的主要化学成分基本相同,微波辐射对薏苡仁油成分无影响.     

微波辅助提取万寿菊花总黄酮的工艺研究

以万寿菊花粉末为原料,采用单因素和正交实验考察了微波辅助提取的微波功率、微波辐射时间、乙醇浓度和料液比对万寿菊花总黄酮得率的影响。结果表明,微波辅助提取万寿菊花总黄酮的最佳工艺条件为:微波功率480 W,微波辐射时间120 s,乙醇浓度70%,料液比1∶40,提取次数2次。在此最佳工艺条件下,万寿菊花总黄酮得率达到40.45 mg/g。     

微波法提取川木香中的木香烃内酯和去氢木香内酯的研究

∶微波法提取川木香中的木香烃内酯和去氢木香内酯,考察了微波功率、辐射时间、料液比对提取率的影响。最优工艺条件是微波辐射功率为400 W,辐射时间为3 min,料液比为1∶30(g/mL)。在此工艺条件下,提取率可以分别达到0.76%和2.31%。     

微波辅助法提取栀子黄色素工艺研究

采用微波辅助提取法对栀子中黄色素成分的提取工艺进行了优选。在单因素试验的基础上,采用正交表L₉(3⁴),以提取剂乙醇体积分数、固液比、微波功率、微波处理时间为因素,以黄色素溶液的吸光度为指标进行试验,得到最佳工艺参数: 1 g栀子粉末,60%的乙醇20 mL,功率280W的微波处理40 s,黄色素得率为17.83%,提取率达到98.20%,与传统的水提和有机溶剂提取相比,不仅提取率高,而且快速、节能。     

Study on the microwave-assisted extraction of polyphenols from tea

This study demonstrated a promising method for quickly extracting tea polyphenol (TP) by microwave-assisted extraction (MAE) technology. Some influential parameters, including MAE temperature, microwave power, concentration of extraction solvent, MAE time and the solid/liquid ratio, were investigated. The optimum condition of MAE was obtained by dual extraction with 60% ethanol (v/v) and the solid/liquid ratio 1:12 g/mL at 80°C for 10 minutes under the microwave power 600W. The yield of TP was 96.5% under the described condition. Compared with traditional methods, including hot reflux extraction (HRE), ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE), the extraction time was saved 8 times than that of HRE, and the yield was increased by 17.5%. The extraction time at comparable levels of production was saved 2 times, and the energy consumption was one fourth that of UAE. The extraction time was saved 5 times than that of SFE, and the yield of TP was increased by 40%. Moreover, compared with MAE of TP studied by others, it decreased the solid/liquid ratio from 1: 20 to 1: 12 g/mL without 90-min pre-leaching time, and the yield of TP was increased by 6%–40%.     

Determination of Anti-Tumor Constitute Mollugin from Traditional Chinese Medicine Rubia cordifolia: Comparative Study of Classical and Microwave Extraction Techniques

Abstract

Rubia cordifolia is a common traditional Chinese medicine (TCM) used for centuries for the treatment of cough, inflammation of the joints, uterine hemorrhage, and uteritis. Mollugin is a major active component present in R. cordifolia and recognized as a potential anti-tumor compound. In this work, a microwave-assisted extraction (MAE) method has been developed for extracting mollugin from R. cordifolia. Several variables that can potentially affect the extraction yield, namely extracting solvent, microwave power, extraction time, and solid-liquid ratio were optimized. The separation and quantitative determination of mollugin was carried out by HPLC with UV detection at 254 nm. Under appropriate MAE conditions, such as extraction time of 4 min, ethanol concentration of 70% (v/v), microwave power of 460 W, and solid-liquid ratio of 1:20 (g/mL), the extraction yield of mollugin from R. cordifolia with MAE was higher than conventional extraction methods such as Soxhlet extraction, heat reflux extraction, and ultrasonic-assisted extraction. Due to the considerable saving in time and its higher extraction yield, the proposed MAE procedure was obviously a more rapid and effective sample preparation technique.     

Study on the microwave-assisted extraction of polyphenols from tea

This study demonstrated a promising method for quickly extracting tea polyphenol (TP) by microwave-assisted extraction (MAE) technology. Some influential parameters, including MAE temperature, microwave power, concentration of extraction solvent, MAE time and the solid/liquid ratio, were investigated. The optimum condition of MAE was obtained by dual extraction with 60% ethanol (v/v) and the solid/liquid ratio 1:12 g/mL at 80°C for 10 minutes under the microwave power 600 W. The yield of TP was 96.5% under the described condition. Compared with traditional methods, including hot reflux extraction (HRE), ultrasound-assisted extraction (UAE) and supercritical fluid extraction (SFE), the extraction time was saved 8 times than that of HRE, and the yield was increased by 17.5%. The extraction time at comparable levels of production was saved 2 times, and the energy consumption was one fourth that of UAE. The extraction time was saved 5 times than that of SFE, and the yield of TP was increased by 40%. Moreover, compared with MAE of TP studied by others, it decreased the solid/liquid ratio from 1 ∶ 20 to 1 ∶ 12 g/mL without 90-min pre-leaching time, and the yield of TP was increased by 6%–40%.     

Optimization of microwave-assisted extraction of wedelolactone from Eclipta alba using response surface methodology

An efficient microwave-assisted extraction technique was used to extract wedelolactone from Eclipta alba. To optimize the effects of the microwave-assisted extraction (MAE) processing parameters on the yield of wedelolactone, a response surface methodology with a central composite rotatable design was employed. Four independent variables were investigated: microwave power, ethanol concentration, extraction time and the solvent-to-solid ratio. The optimum conditions were: microwave power, 208W; ethanol concentration, 90%; extraction time, 26.5min; and solvent-tosolid ratio, 33mL·g^?1. Under the optimal conditions, the extraction yield of wedelolactone was (82.67±0.16)%, which is in close agreement with the value predicted by the statistical model. MAE was also compared to other conventional methods, including ultrasonic assisted extraction, extraction at room temperature and heat reflux extraction. MAE has distinct advantages for the extraction of wedelolactone in terms of both time and efficiency. Therefore, MAE is a reliable method for the extraction of wedelolactone from Eclipta alba.     

加勒比松树皮中原花青素的提取工艺研究

系统研究了以加勒比松树皮为原料提取原花青素的方法及工艺条件。研究对比了常规溶剂浸提、超声波提取及微波辅助提取等方法对原花青素提取得率的影响。实验结果表明,溶剂浸提采用 70% 乙醇溶液时原花青素的得率最高。在3种提取方法中,超声波提取法和微波辅助提取法提取效果较优。前者能在短时间内取得较高的提取得率,而后者需进一步延长微波辅助作用后溶剂浸提的时间才能达到较好的提取效果。超声波提取法的适宜提取条件为: 提取温度 50℃,功率 100 W,料液比1:11,提取时间 1.5 h;微波辅助提取法的适宜提取条件为: 功率 200 W,微波处理时间 30 s,料液比1:11,提取温度 50℃,提取时间 6 h。在上述条件下原花青素得率分别为 7.47% 和 7.69%。     

微波-超声波协同萃取银杏黄酮的工艺研究

以银杏叶为材料,研究了乙醇浓度、微波功率、微波处理时间、料液比、银杏叶粉碎颗粒大小以及微波-超声波协同作用对银杏黄酮提取效率的影响。结果表明微波处理,微波-超声波协同处理可以显著提高银杏黄酮的提取率。确定了最佳的微波处理条件:70%乙醇为萃取液,料液比1∶20,粉末颗粒80目,微波功率50W,微波处理时间4 m in,处理后水浴回流提取2 h所得提取液的黄酮提取率达到81.76%,比直接水浴提取提高了1.3倍,微波-超声波协同处理的黄酮提取率达到83.54%。     

植物药提取废渣中再次提取有效成分的研究

利用微波萃取技术针对某中药厂双黄连制剂生产过程中产生的废弃黄芩提取药渣进行了有效成分的再次提取并同传统水提工艺进行了对比。以有效成分(黄芩苷)收率做为考察指标,用正交设计结合单因素分析方法考察微波提取黄芩苷的最佳提取条件,旨在探讨植物药提取废渣的再利用价值、探寻植物药提取废渣资源化的有效途径。结果表明:各因素对黄芩苷收率的影响依次为:乙醇浓度粒径功率提取时间,其中乙醇浓度为显著性影响因素,最佳工艺为:以30%乙醇作为提取溶剂,黄芩药渣粒径80目,微波功率选择500W,微波提取2min。与水提工艺相比,在最佳工艺条件下,微波提取工艺能够获得较高收率的黄芩苷。