黄芪多糖超声-微波协同提取研究

本论文采用超声-微波协同提取新工艺,通过单因素实验分别考察提取时间、微波功率、料液比等因素对黄芪多糖提取率及纯度的影响;通过正交实验得出最佳提取工艺参数;通过平行提取实验,与水提法、微波及超声波辅助提取进行比照。得出最佳提取条件为微波功率120 W,提取时间为150 s,料液比1∶25(g/mL)时,黄芪多糖的提取率最高达4.25%,并且证明了超声微波协同提取法的提取效率高于水提法、微波法及超声波法等传统的提取方法。     

酶解破壁促进废次烟叶中茄尼醇溶浸

协同应用纤维素酶和木质素酶催化降解废次烟叶,探讨清洁高效的酶解破壁效应及浸提茄尼醇工艺条件。结果发现复配酶催化裂解溶浸茄尼醇效果明显优于单一酶,酶解时间、温度、pH值以及酶投加量等条件均影响酶破壁浸提茄尼醇能效。结果表明,采用纤维素酶：木质素酶酶活比15∶1 (U/U) 的复配酶,在体积为5倍烟草质量的水介质环境中,当复配酶投加量为175 U/g,水浴温度40 ℃,pH=6时,催化酶解烟叶8 h后,茄尼醇溶浸浓度可达0.33 g/L。在此条件下,茄尼醇平均提取率可达96.53％,是化学回流浸提方法的1.68倍。该方法为有效提取废次烟草中茄尼醇提供了一种新途径。     

超临界CO2萃取烟叶中茄尼醇的工艺研究

采用超临界二氧化碳萃取烟叶中的茄尼醇,考察了萃取过程温度、压力、二氧化碳流量、萃取方式、夹带剂种类及其用量对萃取过程的影响。采用四因素三水平的正交设计,以茄尼醇的提取率为指标,对萃取条件进行了优化。并建立了能较准确测定烟叶中游离茄尼醇含量的方法,采用高效液相色谱对萃取产物进行了分析。以探索提高提取率的方法,为其工业化生产提供参考。结果表明：最佳萃取工艺条件为：甲醇为夹带剂,萃取温度45℃,萃取压力25 MPa,CO₂流量15 kg·h^-1。在最佳工艺条件下茄尼醇的提取率为：92.1%。     

皂化法分离测定三孢布拉氏霉菌体中辅酶Q10的研究

目的:为研究醇碱皂化法分离三孢布拉氏霉菌体中辅酶Q10的最佳工艺。方法:采用正交实验,对醇碱皂化法分离测定三孢布拉氏霉菌体中辅酶Q10的各工艺条件进行了研究。结果:皂化时间、醇碱浓度及焦性没食子酸添加量对皂化效果影响显著,而温度(50~90℃)对其影响较小。醇碱皂化法提取三孢布拉氏霉中辅酶Q10的最佳工艺条件为:KOH加入量为湿菌体的1/2(w/w),醇碱浓度为10%,焦性没食子酸量添加量为湿菌体的10%(w/w),在70℃下皂化60min。此提取工艺平均回收率达81.8%,RSD为2.6%。     

超声微波协同萃取(UMAE)番茄中番茄红素的研究

研究了超声微波协同萃取番茄中的番茄红素。以乙酸乙酯为萃取溶剂并以不同的提取时间、微波功率和液固比作为参数进行实验,并进行了工艺优化。在提取时间367s、微波功率98W和液固比10．6：1的条件下实际提取率可达到97．4％。实验结果表明：UMAE法是一种能够快速有效的提取番茄红素的方法。     

超临界CO2萃取烟叶中茄尼醇的工艺研究

采用超临界二氧化碳萃取烟叶中的茄尼醇,考察了萃取过程温度、压力、二氧化碳流量、萃取方式、夹带剂种类及其用量对萃取过程的影响。采用四因素三水平的正交设计,以茄尼醇的提取率为指标,对萃取条件进行了优化。并建立了能较准确测定烟叶中游离茄尼醇含量的方法,采用高效液相色谱对萃取产物进行了分析。以探索提高提取率的方法,为其工业化生产提供参考。结果表明:最佳萃取工艺条件为:甲醇为夹带剂,萃取温度45℃,萃取压力25MPa,CO2流量15kg·h-1。在最佳工艺条件下茄尼醇的提取率为:92.1%。     

提取防风多糖的工艺优化

采用超声波强化和微波辅助提取2种方法提取防风多糖,并与传统热水浸提法在多糖的提取率上进行比较。防风多糖超声提取的最佳工艺条件为超声功率1 000 W、提取时间25 min、液固体积质量比为25,防风多糖微波提取的最佳工艺条件为微波功率560 W、液固体积质量比为30、提取时间10 min,在最佳提取工艺下,2种方法的提取率分别为6.103%和7.639%。与传统热水浸提法相比,超声法和微波法提取防风多糖具有迅速、节能、高效、提取率高等诸多优点。     

松花粉黄色素的超声/微波协同提取工艺及其稳定性研究北大核心CSCD

本文以东北野生马尾松松花粉为原料,研究超声/微波协同提取松花粉黄色素的工艺和松花粉黄色素的溶解性以及p H值、温度、光照、食品添加剂和6种常见金属离子对其稳定性的影响。结果表明:超声/微波协同提取松花粉黄色素的最佳工艺参数为微波功率351.4 W,液料比25.4 m L/g,提取时间11.9 min;松花粉黄色素在酸性条件下稳定性较好,碱性环境对其有增色作用,对光和热有较好的耐受性,K+、Mg2+、Ca2+和Al3+的影响小,Cu2+和Fe3+对其有一定的影响,食盐、葡萄糖、蔗糖、苯甲酸钠的影响较小,碳酸钠和苯甲酸钠对色素稍有增色作用,维生素C和柠檬酸稍有减色作用。试验结果表明松花粉黄色素稳定性良好,本研究结果为开发应用松花粉黄色素奠定了基础,为松花粉黄色素的提取加工及工业应用提供了依据。     

松花粉黄色素的超声/微波协同提取工艺及其稳定性研究

本文以东北野生马尾松松花粉为原料,研究超声/微波协同提取松花粉黄色素的工艺和松花粉黄色素的溶解性以及p H值、温度、光照、食品添加剂和6种常见金属离子对其稳定性的影响。结果表明:超声/微波协同提取松花粉黄色素的最佳工艺参数为微波功率351.4 W,液料比25.4 m L/g,提取时间11.9 min;松花粉黄色素在酸性条件下稳定性较好,碱性环境对其有增色作用,对光和热有较好的耐受性,K+、Mg2+、Ca2+和Al3+的影响小,Cu2+和Fe3+对其有一定的影响,食盐、葡萄糖、蔗糖、苯甲酸钠的影响较小,碳酸钠和苯甲酸钠对色素稍有增色作用,维生素C和柠檬酸稍有减色作用。试验结果表明松花粉黄色素稳定性良好,本研究结果为开发应用松花粉黄色素奠定了基础,为松花粉黄色素的提取加工及工业应用提供了依据。     

超声微波协同提取小米糠总黄酮工艺及其抗炎活性研究

对小米糠总黄酮的超声微波协同提取工艺和抗炎活性进行研究。在单因素试验基础上,采用Box-Behnken方法设计多因素试验,研究超声微波时间、乙醇浓度、料液比、微波功率对小米糠总黄酮提取量的影响,建立试验工艺参数与提取量之间的数学模型,确立最佳提取工艺,并对其进行光谱表征;并通过小米糠总黄酮对脂多糖(LPS)诱炎症RAW264.7巨噬细胞的增殖及促炎性细胞因子试验,测定其抗炎活性。超声微波协同萃取小米糠总黄酮的最佳工艺参数为:超声微波时间为0.87 h,乙醇浓度为77%,料液比为1∶19 g/m L,微波功率为486 W,此时提取量为31.26 mg/g,较传统的乙醇回流法提高205%;结果表明小米糠总黄酮结构与芦丁基本一致;小米糠总黄酮浓度在50~200μg/m L范围内,可以明显降低LPS对巨噬细胞增殖的抑制作用、修复细胞形态及显著下调胞内促炎性因子的分泌,并且呈剂量依赖性关系。这表明小米糠总黄酮具有一定的抗炎效果,是一种潜在的免疫调节剂。     

Recovery of solanesol from tobacco as a value-added byproduct for alternative applications

Solanesol in the waste streams of a bioprocess designed for alternative applications of low-alkaloid tobacco was recovered using three different extraction methods. Compared to the conventional heat-reflux extraction (HRE) and ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) using 1:3 hexane:ethanol (v/v) as the solvent after saponification treatment of tobacco biomass was found the most effective in terms of solanesol yield, processing time, and volume of solvent consumed. Quantification of solanesol was achieved by optimizing the mobile phase at 60/40 acetonitrile–isopropanol and lowering the oven temperature to 22 °C using a standard reverse-phase high performance liquid chromatography (RP-HPLC). The total solanesol recovered from tobacco biomass and chloroplast accounted for 30% (w/w) of the total solanesol in the fresh leaves. Since solanesol is the precursor of metabolically active quinones such as coenzyme Q10 and vitamin K analogues, extraction of solanesol from tobacco bioprocess waste is a feasible operation and could leverage the overall profitability of biorefining tobacco for alternative, value-added uses.     

Rapid determination of solanesol in tobacco by high-performance liquid chromatography with evaporative light scattering detection following microwave-assisted extraction

Solanesol is the starting material for many high-value biochemicals, including coenzyme Q(10) and Vitamin-K analogues. The aim of the current study was to develop a reliable and fast analytical procedure for the determination of solanesol in tobacco using high-performance liquid chromatography (HPLC) with evaporative light scattering detection (ELSD) coupled with microwave-assisted extraction (MAE) as an efficient sample preparation technique. The HPLC conditions were Agilent C18 column using acetonitrile-isopropanol (60:40, v/v) as mobile phase at a flow rate of 1 ml/min. ELSD conditions were optimized at nebulizer-gas flow rate of 1.5 l/min and drift tube temperature of 65 degrees C. The method was validated to achieve the satisfactory precision and recovery, and the calibration range was 0.1-1.5 mg/ml. The developed analytical procedure was successfully applied to determine solanesol content in tobacco samples from different growing regions in China.     

β-环糊精包合雨生红球藻皂化产物可行性研究

本文以雨生红球藻皂化产物中虾青素含量为评价指标,对β-环糊精包合雨生红球藻皂化产物可行性进行了实验研究。试验结果表明,当雨生红球藻粉在优选的实验条件下皂化产物经β-环糊精包合后,HPLC检测主要成分组成未见明显变化,包合率可达到90%。于温度40℃,湿度75%条件下进行稳定性加速实验,结果表明,经皂化后包合物中虾青素稳定性较好,达到了药物和保健食品原料的稳定性要求,说明该方法可行。     

HPLC法测定烟草不同部位、不同提取方法茄尼醇的含量

为了建立烟草不同部位、不同烟草原料中茄尼醇的含量测定方法,本文取烟草不同部位经甲醇超声提取及烟草不同提取方法的提取物,分别用高效液相色谱法测定茄尼醇的含量。结果显示,烟草茎及叶柄中茄尼醇含量极低,烤烟中的茄尼醇的含量：中部烟〉上部烟〉下部烟,烟叶档次越高茄尼醇含量越高。提取溶媒为石油醚〉丙酮〉乙醇。     

Extraction of astaxanthin from Haematococcus pluvialis by supercritical carbon dioxide fluid with ethanol modifier

Conventional solvent extraction methods cannot attain high‐quality antioxidant extracts from microalgae and also require solvent recovery and posttreatment. In this study, we utilized environmental friendly supercritical carbon dioxide fluid extraction (SFE‐CO₂) techniques to obtain pigment (i.e. astaxanthin) from Haematococcus pluvialis. The effects of key operating parameters on the extraction efficiency of astaxanthin were investigated, giving an optimal condition of H. pluvialis weight, 6.5 g; CO₂‐flow rate, 6.0 NL/min; extraction time, 20 min; extraction pressure, 4500 psi; volume of ethanol modifier added, 9.23 mL/g; extraction temperature, 50°C; modifier composition, 99.5%. Under these optimum conditions, the astaxanthin yield was 73.9% (10.92 mg/g dry H. pluvialis powder) after eight cycle of extraction cycles. The saponification index (C_S/C₀, representing the ratio of astaxanthin concentration after and before the saponification procedures) of the extract could be increased from 1 to 12.78 by saponification with 3.5 M NaOH.     

Saponification of esters of chiral alpha-amino acids anchored through their amine function on solid support.

Anchoring an alpha-amino acid residue by its amine function onto a solid support is an alternative to develop chemistry on its carboxylic function. This strategy can involve the use of amino-acid esters as precursors of the carboxylic function. A complete study on the Wang-resin was performed to determine the non racemizing saponification conditions of anchored alpha-amino esters. The use of LiOH, NaOH, NaOSi(Me)3, various solvents and temperatures were tested for this reaction. After saponification and cleavage from the support, samples were examined through their Marfey's derivatives by reversed phase HPLC to evaluate the percentage of racemization.     

Selective extraction of free astaxanthin from Haematococcus culture using a tandem organic solvent system

A novel tandem solvent process of dodecane and methanol was developed for the selective extraction of free astaxanthin from red encysted Haematococcus culture. The process consists of dodecane extraction for astaxanthin mixture from the culture (stage 1) and methanol extraction for free astaxanthin from the dodecane extract (stage 2). In the first stage, astaxanthin mixture was directly extracted to dodecane from the culture broth without cell harvest process, followed by a rapid separation of the dodecane extract and the culture medium containing cell debris by simple settling. In the second stage, free astaxanthin was selectively collected to methanol from the dodecane extract, accompanied with saponification of astaxanthin-esters by the addition of NaOH to methanol. During saponification, use of the optimum NaOH concentration (0.02 M) and low temperature (4 degrees C) reaction minimized the degradation of free astaxanthin, resulting in a total recovery yield of free astaxanthin of over 85%. The free-astaxanthin-containing methanol extract was also simply separated from dodecane by gravity settling, after which the astaxanthin-free dodecane was effectively recycled to the first stage, yielding a stable extractability of astaxanthin mixture during repeated extraction. Our results indicate the potential of the proposed tandem solvent process as an alternative extraction technology for the high-value antioxidant Haematococcus astaxanthin.     

淀粉类保水剂合成过程中皂化介质对吸水性的影响

合成适用于工业生产的淀粉接枝共聚物保水剂。系统地考察了淀粉接枝共聚物在皂化过程中,分散介质对产物吸水性能的影响。     

Coenzyme Q10 production by Sphingomonas sp. ZUTE03 with novel precursors isolated from tobacco waste in a two-phase conversion system

Coenzyme Q10 (CoQ10) is a widely used supplement in heart diseases treatment or antioxidative dietary. The microbial production of CoQ10 was enhanced by addition of solanesol and novel precursors recovered from waste tobacco. The novel precursors were separated by silica gel and identified as alpha-linolenic acid (LNA) and butylated hydroxytoluene (BHT) based on the effect on CoQ10 production and GC-MS. The effects of novel precursors on CoQ10 production by Sphingomonas sp. ZUTE03 were further evaluated in a two-phase conversion system. The precursor's combination of solanesol (70 mg/l) with BHT (30 mg/l) showed the best effect on the improvement of CoQ10 yield. A maximal CoQ10 productivity (9.5 mg l-1 h-1) was achieved after 8 h conversion, with a molar conversion rate of 92.6% and 92.4% on BHT and solanesol, respectively. The novel precursors, BHT and LNA in crude extracts from waste tobacco leaves, might become potential candidates for application in the industrial production of CoQ10 by microbes.