超临界二氧化碳精制辣椒红色素的研究

采用超临界二氧化碳萃取技术对有机溶剂萃取的辣椒红粗提物进行提纯、精制,制备高色价、高质量的辣椒红色素产品。研究了萃取压力、萃取时间等因素对产品色价及收率的影响,添加夹带剂对萃取效果的影响,得到较佳的工艺条件为：萃取压力17MPa(添加夹带剂)、14MPa(添加夹带剂),萃取时间4h。结果：未添加夹带剂产品色价由原来的60提高到150,产品收率为93％;加有夹带剂的产品比未加夹带剂的产品色价高出20,产品收率高2％;辣素含量更低,基本无法检出：溶解性更好,无不溶物：脱辣、脱臭效果好,不含任何异味、杂味。     

辣椒红色素和辣椒碱的研究进展

综述了辣椒红色素和辣椒碱的性质、提取方法及用途。简要介绍了辣椒红色素和辣椒碱的应用前景。     

辣椒红色素制备新工艺研究

辣椒红色素在食品添加剂、饮料、化妆品和医药行业中应用广泛,有着较大的市场需求。今用正己烷(60℃,液固比5:1,提取时间3.5 h,提取2次)从辣椒中提取得到辣椒红色素粗提物,再用液-液萃取法精制;重点考察了乙醇溶液的浓度、原料液和乙醇溶液比值、萃取次数等对萃取过程的影响,建立了一条从辣椒中提取辣椒红色素的工艺路线。萃取过程合适的工艺条件为:常温下,选用60%(V/V)乙醇水溶液作萃取剂,原料液和萃取剂的体积比值为4:1,萃取一次。在上述条件下,得到的辣椒红色素的色价和辣椒素含量分别为87.3,0.16%,达到GB10783-2008要求。     

辣椒红色素的国内研究进展

综述了辣椒红色素的用途、性质、提取方法及分析方法。列举了油溶法、有机溶剂法和超临界CO2流体萃取等典型的提取方法,并简要介绍了辣椒红色素的应用前景。     

超临界CO2萃取辣椒红色素工艺条件的研究

本文通过对萃取压力、萃取温度、萃取时间等条件的探索,获得了最佳的工艺参数。实验结果表明,超临界萃取法具有工艺简单、操作安全、产品质量好、萃取效率高等优点。     

超临界CO2萃取红花药渣中挥发油和红色素

在0.5 L半连续装置上,考察了温度、压力、CO2流量及物料粒径等工艺条件对超临界CO2分级萃取红花水煮醇提药渣的影响,得到了红花挥发油和红花红色素,对红色素含量进行了测定,并同红花分级萃取进行了对比. 结果表明,温度、压力及CO2流量对分级萃取影响明显. 在考察范围内最佳工艺条件为：一级萃取温度35℃、压力9 MPa、CO2流量3.74 kg/h;二级萃取温度35℃、压力30 MPa、CO2流量3.74 kg/h. 在此条件下红花挥发油萃取率达2.74%,红色素相对收率达69.88%.     

辣椒红色素晶体制备技术的研究

色价为１００的油状辣椒红色素１００ｇ,加入１００ｍｌｃ（ＮａＯＨ）＝３．７５ｍｏｌ／Ｌ的溶液,并添加１％（ｗ）维生素Ｅ作为水解保护剂,９０℃下反应１．１７ｈ,得到吸附色素的固体皂化物,用饱和食盐水洗至中性,离心除去水分,用丙酮（３×５００ｍｌ）萃取皂化物中所吸附的色素,蒸馏除去丙酮,然后用３０ｍｌ石油醚（沸点６０～９０℃）结晶,得到辣椒红色素的晶体８．１ｇ,色价为１０１３。     

辣椒红色素乳状液制备工艺的研究

以辣椒油树脂为原料,以吸光度和色素上浮率为评价指标,分别考察了乳化剂的HLB值、复合乳化剂类型及用量、稳定剂类型及用量对辣椒红色素乳状液稳定性的影响。结果表明,乳液中色素含量为8.0%体系,所选的HLB值应在13.34左右;采用复合乳化剂Span-20(2.5%)+SE(37.5%)+Tween-80(60%),用量为0.6%;选用0.30%{海藻酸钠(0.20%)+羧甲基纤维素钠(0.10%)}时,乳化效果最佳,乳状液最稳定并观察其微观结构与粒径分布。     

辣椒红色素的提取工艺研究

本文以红辣椒为原料,考察了提取辣椒红色素的几个影响因素,确定了提取辣椒红色素的优化条件。实验结果表明,提取的最佳条件为:提取溶剂为石油醚,原料粒度为20~40目,液固比为9:1mL/g,提取时间4h。     

超临界气体提取技术进展

讨论了超临界气体提取技术中气体的选择原则、提取装置的现状及其应用中工艺条件的选定,并对国内的研究工作提出了建议。     

超临界流体萃取技术的应用及研究进展

超临界流体萃取技术近年来被广泛应用于中草药、食品、香料、化工及环境保护等领域。介绍了超临界流体萃取技术与传统的萃取方法相比所具备的优势及其发展前景。     

辣椒红色素提取工艺研究

以邱北辣为原料,以辣椒红色素相对量为评价指标,考察了提取温度、提取时间、液料比以及提取次数对辣椒红色素提取的影响。在单因素实验的基础上,采用正交实验对辣椒红色素的提取工艺进行优选。结果表明,以乙酸乙酯为提取溶剂,提取温度80℃,提取时间95 m in,液料比(mL/g)为20∶1,提取2次时,提取的辣椒红色素色价可达105.6,得率为9.68%。     

Titania aerogels prepared by low-temperature supercritical drying. Influence of extraction conditions

Titania aerogels with meso- to macroporosity and high specific surface area were prepared by varying the conditions of semicontinuous extraction of methanolic titania gels with CO₂. The conditions varied were extraction temperature, extraction duration, and CO₂ in liquid or supercritical state. The resulting titania aerogels were characterised by means of nitrogen physisorption, X-ray diffraction, thermal analysis and transmission electron microscopy. All uncalcined aerogels contained significant amounts of organic residues (12–14 wt% elemental carbon), and remained X-ray amorphous during calcination in air up to 673 K. Thermoanalytical studies showed that crystallization generally occurred in the range 730–745 K. The variation of the extraction temperature at either constant density or pressure of CO₂, the use of either liquid or supercritical CO₂, and the duration of extraction greatly influenced surface area, pore size distribution, and pore volume. The highest specific surface area (623 m² g^–1) and nitrogen pore volume (4.0 cm³ g^–1) were obtained, if the density of supercritical CO₂ corresponded to that of methanol at the lowest temperature applied (313 K). The studies indicate that textural properties can be varied over a wide range by choosing appropriate extraction conditions.     

超临界CO2萃取丁香油的数值模拟

为了预测超临界CO₂萃取挥发油动态过程,根据挥发油在超临界CO₂与物料之间的质量传递平衡,采用集总参数法建立超临界CO₂萃取丁香油过程的数学模型。结合不同温度、压力、粒径和CO₂流速条件下的实验结果,对方程进行了合理的简化,并利用实验数据拟合出模型中CO₂密度、粒径和流速的系数。验证结果表明模型的计算值和实验值的平均相对误差在6. 88%～57. 78%之间,建立的数值模型能较好地描述实际的超临界CO₂萃取丁香油行为。     

超临界CO_2流体萃取植物油的实验研究

建立了一套超临界流体萃取实验装置,就大豆和花生两种植物油超临界流体萃取进行了较为详细的实验研究.在探讨了压力、温度、颗粒度、空隙率以及时间等对萃取率的影响之后,获得了指导实际生产的最佳工艺参数条件.     

超临界CO2萃取含油污泥研究现状与进展

含油污泥是一种含有大量有机物、絮状体的复杂多相稳定乳化胶体体系,主要来源于油气开采和集输过程。污泥中的含油量一般为10%~30%（体积分数）,利用超临界二氧化碳（supercritical CO₂,scCO₂）提取和回收其中的油基成分可实现污泥的无害化处理,并产生可观的经济效益。本文综述了scCO₂萃取原理及工业化应用情况,分析了萃取条件及携带剂对萃取率的影响,重点论述了scCO₂萃取含油污泥的相平衡热力学及动力学机制研究进展。指出应坚持实验与理论相结合的手段,着重开展以下三方面的研究：①针对含油污泥组成复杂、极性组分含量高的特点,结合scCO₂与含油污泥多组分复杂体系相平衡实验,建立scCO₂萃取含油污泥的相平衡模型,阐明scCO₂萃取含油污泥的相平衡特征及影响因素;②考虑不同分子间的键结合能与非键结合能,从scCO₂萃取油基的微观效应出发,探究油基与污泥基质间的吸附、解吸及扩散规律,定性描述、定量揭示scCO₂萃取油的动力学特征与作用机制;③考虑萃取工艺的经济性,以萃取率最高为目标函数,建立萃取条件优化模型,为scCO₂萃取含油污泥工艺的设计、优化及工业化应用提供理论与技术支撑。     

Quality of wheat germ oil extracted by liquid and supercritical carbon dioxide

The extraction of wheat germ oil by liquid and supercritical CO₂ is described from the point of view of both operative method and pretreatment of raw material. The best conditions for wheat germ oil extraction are: pressure, 150 bar; temperature, 40°C; and solvent flow rate, 1.5 L/min at standard temperature and pressure. The yields and fatty acid compositions obtained are very similar to those resulting from the conventional extraction process using hexane as solvent (8.0 wt%), although a higher-quality oil is obtained by using CO₂ as solvent (free fatty acids, 12.4%; tocopherol content, 416.7 mg tocopherol/g wheat germ oil). These factors lead to the conclusion that the extraction process using CO₂ could be economically competitive with the conventional process, since it considerably simplifies the oil refinement stages and completely eliminates the solvent distillation stage, which are the most costly processing steps in terms of energy consumption.     

超临界流体萃取天然产物传质模型

为开发超临界流体萃取天然产物过程简单可靠的传质理论模型,对其传质机理进行了分析,由微分质量衡算方程经合理简化得到了动力学模型的解析解.定义了新准数B_z(可以确切地表征萃取过程的动态传质状况)和特征时间t_k,当t=t_k时,-dr_c/dt取得极小值,其原因可能是由内扩散传质阻力与内扩散传质推动力（浓度差）相竞争的结果.采用此数学模型计算了完全萃取时间t_ex、萃取收率Y随时间t的变化以及流体流率Q对萃取收率Y的影响,计算结果与文献中的实验数据吻合良好.本模型简单可靠,可用于超临界流体萃取天然产物过程的预测、分析、设计、模拟和优化.     

Preparative-scale supercritical fluid extraction/supercritical fluid chromatography of corn bran

A preparative-scale supercritical fluid extraction/supercritical fluid chromatography (SFE/SFC) procedure has been developed for the removal of oil from corn bran to obtain fractions enriched with free sterols and ferulate-phytosterol esters (FPE). Operational parameters from an analytical-scale supercritical fluid fractionation technique were translated to and optimized on a home-built, preparatory-scale SFE/SFC apparatus. SFE was performed at 34.5 MPa and 40°C using supercritical carbon dioxide. These conditions did not result in exhaustive extraction of the corn bran, but yielded about 96% of the available oil. SFC was conducted in three steps, followed by reconditioning of the sorbent bed. Preparative-scale SFE/SFC of corn bran produced a fraction enriched greater than fourfold in free sterols and 10-fold in FPE, suggesting that such a scheme could be used industrially to produce a functional food ingredient.