Study on the green extraction of corncob xylan by deep eutectic solvent

Corn as one of the world's major food crops,its by-product corn cob is also rich in resources.However,the unreasonable utilization of corn cob often causes the environmental pollution,waste of resources and other problems.As one of the most abundant polymers in nature,xylan is widely used in food,medicine,materials and other fields.Corn cob is rich in xylan,which is an ideal raw material for extracting xylan.However,the intractable lignin is covalently linked to xylan,which increases the difficulty of xylan extraction.It has been reported that the deep eutectic solvent(DES)could preferentially dissolve lignin in biomass,thereby dissolving the xylan.Then,the xylan in the extract was separated by ethanol precipitation method.The xylan precipitate was obtained after centrifugation,while the supernatant was retained.The components of the supernatant after ethanol precipitation were separated by the rotary evaporator.The ethanol,water and DES were collected for the subsequent extraction of corn cob xylan.In this study,a novel way was provided for the green production of corn cob xylan.The DES was used to extract xylan from corn cob which was used as the raw material.The effects of solid-liquid ratio,reaction time,reaction temperature and water content of DES on the extraction rate of corn cob xylan were investigated by the single factor test.Furthermore,the orthogonal test was designed to optimize the xylan extraction process.The structure of corn cob xylan was analyzed and verified.The results showed that the optimum extraction conditions of corn cob xylan were as follows:the ratio of corn cob to DES was 1:15(g:mL),the extraction time was 3 h,the extraction temperature was 60℃,and the water content of DES was 70%.Under these conditions,the extraction rate of xylan was 16.46%.The extracted corn cob xylan was distinctive triple helix of polysaccharide,which was similar to the structure of commercially available xylan.Xylan was effectively and workably extracted from corn cob by the DES method.This study provided a new approach for high value conversion of corn cob and the clean production of xylan.

Removal of chromium(Ⅲ) from aqueous waste solution by predispersed solvent extraction

The extraction experiments of chromium（W） from aqueous waste solution by predispersed solvent extraction （PDSE） process with extractant （HEHPEHE） and its mixture, including acidic extractant （D2EHPA）, alkaline extractant （TOA） and neutral extractant （TBP） were carried out respectively. It is found that the extractant HEHPEHE exhibited high extraction selectivity to chromium（III） from aqueous waste solution. The colloidal liquid aphrons （CLAs） were successfully generated using kerosene as a solvent, HEHPEHE as an extractant, sodium dodecyl benzene sulphate （SDBS） as a surfactant in aqueous phase and polyoxyethylene sorbitol anhydride monolaurate （Tween-20） in oil phase. To study the extraction efficiency and advantages of the PDSE process in the removal of chromium（III）, the effects of major factors, such as initial chromium（III） concentration, volume of colloidal gas aphrons （CGAs）, HEHPEHE volume fraction, phase ratio （solvent phase to water phase）, mass fraction of dodecyl trimethylammonium bromide （HTAB）, mass fraction of SDBS, mass fraction of Tween-20 and initial pH of aqueous waste solution were also investigated and the appropriate process conditions were obtained. Under the appropriate conditions, the extraction efficiency of chromium（III） above 99.9 % can be achieved and the treated aqueous waste solution can be discharged directly without polluting the environment.

Optimization of Sesame Oil Extraction Process Conditions

In this study, the optimum operating conditions for sesame oil extraction were studied. N-hexane was used as a solvent. Different variables were investigated;sesame seeds particle sizes, ratio of solvent to seeds mass, contact time, stirring effect, roasting impact and extraction temperatures. Results obtained showed that higher rates of extraction were obtained when roasting sesame seed to 15℃. The ratio of solvent to seeds found to be 6:1 gave higher extraction. Moreover, stirring speed was tested and had been optimized to 600 rpm. Finally, the extraction under heating was studied and results showed that increasing operating temperature to more than 40℃ did not increase extraction efficiency.

Analysis of volatile components in saffron from Tibet and Henan by ultrasonic-assisted solvent extraction and GC-MS

To determine the chemical constituents of volatile components in saffron from the Tibet Autonomous Region and the Henan Province of China and to compare the chemical composition difference in the saffron,the total volatile components were extracted by ultrasonic-assisted solvent extraction（USE）,using five different solvents：diethyl ether,ethanol,ethyl acetate, dichloromethane and acetone,analyzed using gas chromatography-mass spectrometry（GC-MS）and compared to the standard MS data,and their relative contents were calculated by area normalization.The results showed both that USE was an efficient and rapid method for the extraction of the volatile components from saffron and that the components extracted from the same sample using different solvents were different.Comparison of the experimental results of saffron from the Tibet Autonomous Region and the Henan Province of China showed that their volatile components were different in their chemical composition and in their relative percentages.USE/GC-MS is a simple,rapid,and effective method for the analysis of volatile oil components in saffron.

Optimization of separation processing of copper and iron of dump bioleaching solution by Lix 984N in Dexing Copper Mine

The effects of the concentration of Lix 984N,phase ratio,initial pH value of aqueous phase and extraction time on the extraction of copper and iron under the condition of low Cu2+ /Fe3+ ratio in dump bioleaching solution of Dexing Copper Mine were explored.The optimal conditions of extraction are as follows: the concentration of Lix 984N 10%; the phase ratio (O/A) 1:1; the initial pH value of aqueous phase 1.5 and the mixing time 2 min.The stripping experiments show that H2SO4 solution could efficiently recover copper from the organic phase under the optimal conditions.

金银花总黄酮低共熔溶剂提取工艺优化

目的优化金银花总黄酮低共熔溶剂提取工艺。方法在单因素试验基础上,以1,3-丁二醇与氯化胆碱比例、液料比、超声时间为影响因素,总黄酮得率为评价指标,响应面法和BP神经网络优化提取工艺。结果BP神经网络优化总黄酮得率高于响应面法优化。最优条件为1,3-丁二醇与氯化胆碱比例2.7∶1,液料比27∶1,超声时间29 min,总黄酮得率为7.85%。结论该方法稳定可靠,可用于低共熔溶剂提取金银花总黄酮。

超声辅助低共熔溶剂法提取太白贝母总黄酮及其抗氧化活性研究

采用超声辅助低共熔溶剂法提取太白贝母总黄酮,以太白贝母总黄酮提取率为考察指标,通过单因素实验和响应面法对提取工艺进行了优化,并通过DPPH自由基清除实验和ABTS自由基清除实验研究了其抗氧化活性。结果表明,在超声功率为69 W、料液比为1∶18(g∶mL)、超声温度为79℃、超声时间为27 min的最优工艺条件下,太白贝母总黄酮提取率可以达到17.7004%,与预测值相差极小;太白贝母总黄酮是一种强抗氧化剂,对DPPH自由基、ABTS自由基具有较强的清除能力,在浓度为16 mg·mL^(-1)时,清除率分别达到82.15%、90.42%,与VC无明显差异。超声辅助低共熔溶剂法操作简便、提取率高,适用于太白贝母总黄酮的提取。该研究为太白贝母药材资源的开发利用提供了参考。

甲乙酮丁烯提浓萃取剂再生工艺优化

通过对甲乙酮装置萃取溶剂组成进行分析,确定了萃取溶剂中杂质的组成。通过流程模拟对萃取剂再生系统工艺进行了研究,找到了装置杂质脱除效果不佳的关键因素。根据模拟计算结果,对装置现有操作条件进行优化调整,优化后萃取剂杂质脱出效果明显,达到萃取溶剂再生的指标要求。

黄连生物碱超声辅助低共熔溶剂提取工艺优化

目的优化黄连生物碱超声辅助低共熔溶剂提取工艺。方法以葡萄糖-乳酸(1∶5)为低共熔溶剂。在单因素试验基础上,以提取时间、含水量、液料比为影响因素,生物碱得率为评价指标,Box-Behnken响应面法优化提取工艺。结果最佳条件为提取时间35 min,含水量26%,液料比33∶1,生物碱得率为7.22%。结论该方法稳定可靠,切实可行,可为黄连开发利用提供参考。

铁皮石斛多糖的低共熔溶剂提取工艺优化

为提高铁皮石斛的综合利用率,建立一种绿色高效的铁皮石斛多糖提取方法。本研究以铁皮石斛多糖提取率为指标,通过单因素考察了低共熔溶剂浓度、提取温度及液料比对铁皮石斛多糖提取率的影响,采用响应面设计优化铁皮石斛多糖的提取工艺,并对纯化后的多糖进行结构分析。结果表明:响应面优化后得到最佳工艺为低共熔溶剂(deep eutectic solvent,DES)浓度40%、提取温度80℃、液料比110:1(mL/g),在此条件下实际提取率为33.2%±0.28%,与预测值33.5%接近,多糖的纯度为56.95%±1.2%。多糖经阴离子交换柱及葡聚糖凝胶柱纯化后,纯度可达90.8%,其单糖主要由葡萄糖和甘露糖构成,质量比约为43:37,此外还含有少量的木糖、鼠李糖、核糖等,结构中同时含有α糖苷键和β糖苷键。本研究提供了一种低共熔溶剂提取铁皮石斛多糖的高效绿色提取方案,具有多糖提取率高及绿色的特点,为后续铁皮石斛多糖的开发提供了借鉴。

低共熔溶剂提取黄酮类化合物的研究进展

植物多糖是植物细胞代谢产生的聚合度超过10个的聚糖,是维持生命活动正常运转的基本物质之一,包括淀粉、纤维素、多聚糖、果胶等,常被当作原料或添加剂,在食品、保健品、药品、化妆品等领域广泛应用。随着绿色化学理念的不断深入,低共熔溶剂作为一种新型溶剂可用于植物多糖的提取,具有高效性、可降解、制备简单、易设计等特点。本文总结了近年来应用低共熔溶剂对植物多糖提取的研究进展,旨在为植物多糖的相关研究提供理论依据和参考。

赤泥中稀土提取与分离技术研究进展

稀土元素被誉为“工业维生素”,具有优异的磁、光、电性能。随着新能源汽车等新兴行业对稀土需求量的不断增加,稀土资源日益紧缺,从二次资源中回收稀土已成大势所趋。作为一种重要的二次资源,赤泥的产量高、堆存量大、稀土含量较高。本文介绍了赤泥中稀土元素的赋存状态,概述了从赤泥中提取分离稀土元素的湿法浸出工艺和火法-湿法联合工艺;介绍了溶剂萃取法和离子交换法两种分离工艺的研究现状,对比分析了不同处理工艺的优缺点,并通过比较不同工艺的优劣,指出降低回收成本、提高环境效益是未来赤泥资源化利用研究的重要方向。

低共熔溶剂提取植物多糖的研究进展

植物多糖是植物细胞代谢产生的聚合度超过10的聚糖,是维持生命活动正常运转的基本物质之一,包括淀粉、纤维素、多聚糖、果胶等,常被当作原料或添加剂,在食品、保健品、药品、化妆品等领域广泛应用。随着绿色化学理念的不断深入,低共熔溶剂作为一种新型溶剂可用于植物多糖的提取,具有高效性、可降解、制备简单、易设计等特点。本文总结了近年来应用低共熔溶剂对植物多糖提取的研究进展,旨在为植物多糖的相关研究提供理论依据和参考。

低共熔溶剂提取动物源加工副产物活性物质的研究进展

动物源加工副产物是一座产量巨大、价格低廉的活性物质宝库,对其进行高效开发具有重要研究意义。低共熔溶剂是一种可设计的新型“绿色溶剂”,由比例不同的氢键供体与氢键受体制备而得,具有原料易得、制备简单、结构可设计、可生物降解等优点,广泛应用于化学、食品和药品等多个领域。本文就低共熔溶剂在动物源加工副产物活性物质提取方面的应用进行了简要的综述和展望,以期为动物源加工副产物活性物质的绿色提取提供新策略。

不同热加工工艺下花椒主要苦味物质的鉴定

花椒作为重要的香辛料,其苦味成分的存在对食品的整体风味具有显著影响。为了深入探究花椒苦味成分的形成机制及其影响因素,本研究以苦味强度为指标,利用感官评价对花椒在水煮和油炸时的工艺条件进行单因素优化。进一步地,通过有机溶剂萃取、固相萃取和制备型高效液相色谱技术,从花椒水和花椒油中分离并富集了苦味馏分。随后,利用滋味稀释分析评估了这些苦味馏分对食品感官特性的贡献。此外,采用高效液相色谱-质谱联用技术,对花椒水和花椒油中的苦味成分进行了成分鉴定。研究结果表明,在水煮过程中,花椒用量的增加和水煮时间的延长会增强苦味,而花椒的苦味在油炸过程中会随着温度升高、时间延长和用量增加而增强。推荐花椒水和花椒油的食用、加工条件如下:花椒水推荐在100℃下煮制5 min,花椒用量控制在2 g以下,以减少苦味。而花椒油建议在105~120℃的油炸温度下炸制10~30 min,花椒用量可适量添加,以保持较低苦味。花椒水中主要的苦味物质可能是槲皮素-3-鼠李糖龙胆二糖苷、槲皮素-3,7-二-O-β-D-吡喃葡萄糖苷、槲皮素-3-O-槐糖和荷叶碱,而花椒油中主要的苦味物质是羟基-α-山椒素和羟基-β-山椒素。本研究为花椒的加工利用、品质调控以及除苦抑苦等提供数据参考和理论依据。

Box-Behnken响应面法优选低共熔溶剂提取巴西人参总皂苷工艺

[目的]响应面法优选巴西人参总皂苷提取工艺,为其进一步开发利用提供参考。[方法]以苋科植物巴西人参为研究对象,采用超声辅助低共熔溶剂法提取总皂苷,通过单因素试验对尿素与氯化胆碱摩尔比、含水量、液料比、提取时间进行考察,以总皂苷得率作为评价指标,运用Box-Behnken响应面法对巴西人参总皂苷提取工艺进行优化。[结果]超声辅助低共熔溶剂提取巴西人参总皂苷的最佳工艺为尿素∶氯化胆碱=1∶1、含水量38%、液料比18∶1(mL∶g)、提取时间37 min,在此条件下,总皂苷得率为6.26%。[结论]该方法提取效率高、重复性好、操作简便,可用于巴西人参总皂苷的提取。

超声辅助低共熔溶剂提取车前草总黄酮的工艺研究

为探究车前草总黄酮的最佳提取工艺,以总黄酮提取率为评价指标,在提取温度、反应时间、低共熔溶剂含水量、摩尔比等单因素试验基础上进行响应面优化。结果表明,车前草总黄酮的最佳提取工艺为提取温度34℃,反应时间41 min,低共熔溶剂含水量47%,摩尔比2.2:1。在此条件下,总黄酮的提取率可达6.28%。研究为车前草的开发及综合利用提供理论支撑。

超声辅助低共熔溶剂提取海带多糖工艺优化及其抗氧化活性

为实现海带多糖的高效提取及开发利用,该研究采用超声辅助低共熔溶剂(deep eutectic solvent,DES)对海带多糖进行提取,并评估其抗氧化活性。以海带为原料,以提取的海带多糖量为评价指标,从8种不同的DES中筛选,发现氯化胆碱和乳酸组成的DES可作为最佳溶剂体系。在超声时间2.0 h的基础上,通过单因素试验,进一步使用Box-Behnken试验设计优化超声辅助DES提取海带多糖的工艺。建立三因素回归模型,确定最优的提取条件:提取最佳温度为93℃,DES中氯化胆碱与乳酸的最佳摩尔比为1:2,最佳含水量为20%。在此条件下,海带多糖的提取量达到58.34 mg/g,是传统水提法的4.71倍。此外,该工艺制备的海带多糖显示出较高的自由基清除率和铁离子还原能力。对DPPH自由基和ABTS+自由基清除率的IC50分别为1.53 mg/mL和0.91 mg/mL,当海带多糖浓度为3.5 mg/mL时铁离子还原能力为1.12,羟基自由基清除率为96.01%,提取的海带多糖表现出良好的抗氧化活性,表明超声辅助DES具有提取海带多糖的潜力。

湿法冶金领域脉冲萃取技术与设备研究进展

脉冲萃取塔作为一种高效的液液萃取设备,是湿法冶金技术塔式萃取设备开发的重要方向之一。系统综述了脉冲萃取塔的开发过程,重点探讨了传递过程规律的研究、数学模型的构建,以及计算流体力学(CFD)在设备开发中的应用。回顾了脉冲萃取塔操作与结构参数对流体力学以及传质性能的影响,揭示了传质、传动量等过程中的规律性和影响因素。在此基础上,介绍了CFD模拟和其他计算技术的应用,进一步优化塔的设计与性能。最后,总结了脉冲萃取塔内构件和塔型式的改进方案,指出了未来研究的方向和潜在应用场景,旨在为今后的研究与应用提供有价值的参考。

Box-Behnken响应面法优选低共熔溶剂提取马蹄金总黄酮工艺

目的 优选低共熔溶剂提取马蹄金总黄酮的工艺。方法 以低共熔溶剂体系摩尔比、含水量、超声功率、超声时间为单因素变量,以马蹄金中黄酮类成分提取率为评价指标,采用Box-Behnken响应面法优选总黄酮提取工艺,并进行验证试验。结果 优选的提取工艺为低共熔溶剂氯化胆碱-乳酸(摩尔比1∶2),含水量为70%,超声(功率为180 W)提取30 min。验证试验结果显示,在此条件下的总黄酮提取率与回归模型预测值的相对误差为0.55%。结论 该优选工艺操作简便、重复性好,可用于马蹄金总黄酮的提取。