响应面优化水–乙醇法提取云南咖啡生豆绿原酸工艺研究

以云南卡蒂姆咖啡生豆为原料,采用水–乙醇法对9种绿原酸异构体进行提取。通过单因素实验对物料目数、液料比、水提温度、提取时间、醇浓度和醇提温度进行研究,并采用响应面设计优化水醇提取工艺。结果表明,水–乙醇法提取率（5.21%）显著高于水提法（4.29%）;醇浓度和液料比对绿原酸提取率具有显著性影响（P≤0.01）,单因素和响应面优化得到的水–乙醇法提取绿原酸的最佳工艺条件为：醇提温度60 ℃,提取时间11.67 min,物料目数60目,液料比16.07,醇浓度20.16%,绿原酸提取率为5.31%。     

多因素交互作用导致烘焙咖啡中绿原酸快速降解

研究烘焙温度、时间及基质pH值对咖啡绿原酸的影响,采用小粒生咖啡豆进行不同程度的烘焙实验,分析不同烘焙温度和时间下pH值、质量损失率、水分质量分数、新绿原酸含量、绿原酸含量、隐绿原酸含量及3种异绿原酸异构体的变化情况,并建立绿原酸降解动力学模型,采用化学反应模型验证绿原酸单体的降解情况.结果表明,烘焙咖啡中水分质量分数...     

绿咖啡豆绿原酸的体外抗氧化性活性测定

通过铁离子还原法和DPPH自由基清除法测定绿咖啡豆绿原酸的体外抗氧化活性,结果显示绿咖啡豆绿原酸具有抗氧化能力和清除自由基能力。稳定性试验结果表明,温度对绿咖啡豆绿原酸的DPPH自由基清除稳定性影响不显著;光照对稳定性有一定程度影响;pH值对稳定性影响显著,且绿咖啡豆绿原酸在酸性条件下比在碱性条件下稳定。     

Correlation Between the Stability of Chlorogenic Acids,Antioxidant Activity and Acrylamide Content in Coffee Beans Roasted in Different Conditions

The aim of this study was to determine the effect of different roasting conditions, including temperature, humidity, and roasting air velocity on acrylamide contents in roasted Robusta coffee. In addition, acrylamide concentrations were correlated with the degradation of coffee bean polyphenols and its antioxidant activity. In the process of roasting in a quarter-technological scale apparatus used temperatures ranged from 190 to 216°C. Dry or moist air at a velocity of 0.5 or 1 m s^?1 was used. Beans were roasted to achieve optimal sensory properties. The increase of roasting air velocity regardless of its temperature resulted in the intensification of acrylamide formation. The increase of humidity of roasting air caused a reduction of acrylamide formation, but only at the highest used roasting temperature. However, the modification of roasting conditions to achieve a drop in acrylamide concentration resulted in increased degradation of polyphenols and/or deterioration of antioxidant activity. The optimal roasting parameters were: Temperature 203°C, dry air, and low velocity of roasting air. Under these conditions, the roasted beans were characterized by relatively low level of acrylamide and moderate degradation of polyphenols.     

HPLC法测定焙烤咖啡中咖啡因的含量

建立高效液相色谱法简便准确测定焙烤咖啡中咖啡因的含量.采用色谱分析柱(UltimateTM XB-C18,5μm,4.6×150 mm),流动相:甲醇-水(含2 mL/L乙酸),梯度洗脱,柱温30℃;流速1.0 mL/min;检测波长286 nm;咖啡因质量浓度在5～200 μg/L范围内与色谱峰面积呈良好线形关系(R2=0.9997),平均回收率有97.93%,精密度测试结果的RSD为0.14%.该方法操作简单、结果准确、重复性好.     

高效液相色谱法测定青梅花、枝、叶中绿原酸类化合物

目的：建立反相高效液相色谱法同时测定青梅非果部位(花、枝、叶)中新绿原酸(NCA)、绿原酸(CA)及隐绿原酸(CCA)3 种绿原酸异构体的含量。方法：采用高效液相色谱法梯度洗脱,使用Luna C18 色谱柱,以体积分数2% 乙酸溶液和乙腈为流动相,二极管阵列检测器在波长328nm 处进行检测。结果：该方法线性范围宽,3种绿原酸异构体的线性范围均为5～200μg/mL,NCA、CA、CCA 的检出限分别为0.21、0.16、0.29μg/mL,定量限分别为0.76、0.50、0.98μg/mL,测得青梅花、枝、叶的30% 乙醇提取物中3 种绿原酸异构体的总含量分别为(48.26 ± 0.11)、(10.82 ± 0.04)、(21.33 ± 0.08)μg/g。结论：该方法简便、快速、准确,青梅花、枝、叶是优良的绿原酸类化合物天然资源。     

高效液相色谱法测定结石通胶囊中绿原酸含量

目的建立高效液相色谱法(HPLC)测定结石通胶囊中绿原酸含量的方法。方法采用C18柱(250 mm×4.6 mm,5μm),乙腈-0.5%磷酸溶液(7:93)为流动相,柱温35℃,流速1.0 mL/min,检测波长326 nm。结果绿原酸在0.020 42~1.0210μg范围内,峰面积与进样量线性关系良好,r=0.9999,平均回收率为99.00%,RSD 2.54%(n=9)。结论该方法重复性、准确性良好,可用于测定结石通胶囊中绿原酸含量。     

RP-HPLC测定咽清颗粒中绿原酸含量

目的建立测定咽清颗粒中绿原酸含量的方法。方法以反相C18色谱柱为固定相(250mm×4.60mm,5μm),乙腈-0.4%磷酸溶液(12∶88)为流动相,流速1.0mL·min-1,检测波长327nm。结果绿原酸进样量10～60μg·mL-1范围内与峰面积积分值呈良好的线性关系(r=0.9999);平均回收率97.17%,RSD=1.73%(n=9)。结论本方法简便、可靠、准确,可用于测定咽清颗粒中绿原酸的含量。     

高效液相色谱法测定南果梨中绿原酸的含量

目的建立测定南果梨中绿原酸含量的高效液相色谱法。方法C18色谱柱(250×4.6mm,5μm);流动相甲醇-0.4%磷酸溶液(2575);检测波长327nm。结果精密度试验RSD为1.9%,n=6;加样回收率98.5%～102.6%,RSD为1.6%～2.1%。结论南果梨果心、果肉、果皮中绿原酸的含量分别为1.785、0.271、0.714mg/g。     

高效液相色谱法测定马铃薯块茎的绿原酸含量

目的:建立测定马铃薯块茎中绿原酸含量的高效液相色谱方法,并测定不同品质特点的马铃薯的绿原酸含量。方法:对甲醇浓度、固液比和超声提取时间三个试验因素进行正交试验设计:ZOBAX C18色谱柱,250mm×4．6mm 5μm;流动相:水-甲醇-冰醋酸（20∶80∶2;30∶70∶2;40∶60∶2）;甲醇-0．4%磷酸溶液（10∶90）:流速: 1．0ml/min;柱温:室温;进样体积:5μl;检测波长为327nm。结果:精密度:RSD为3．2%,n=6,加样回收率为97．5%,提取条件为:甲醇浓度70%,固液比1∶100,超声提取时间40min。确定水∶甲醇∶冰醋酸=30∶70∶2为流动相。     

Determination of Organic Acids and Sucrose in Roasted Coffee by Capiillary Gas Chromatography

Capillary gas chromatography was used to obtain high resolution profiles of 27 organic acids, caffeine, and sucrose in dimethylsulfoxide extracts of roast and ground coffees in a sixty-minute analysis. A shortened procedure was also reported for the quantitative determination of S-caffeoylquinic (SCQA) and quinic (QA) acids and sucrose. Nanogram detection limits were achieved and the reproducibility of the method was under 5% relative. Major, commercial brands of caffeinated and decaffeinated coffee produced under different roasting conditions could be distinguished based on their 5-CQA and sucrose content and on the ration of QA-to-SCQA.     

HPLC法同时测定金银花等样品中6种绿原酸异构体的含量

目的:建立HPLC法同时测定茶叶、枸杞叶、地瓜叶、咖啡、金银花中新绿原酸、绿原酸、隐绿原酸、异绿原酸B、异绿原酸A和异绿原酸C的含有量。方法:采用50%甲醇溶液为提取剂,超声波辅助提取30 min,提取液的分析采用Agilent Eclipse XDB-C18色谱柱(4.6 mm×250 mm,5μm),流动相乙腈-0.1%甲酸溶液,梯度洗脱;流速1.0 mL/min,进样量10μL,检测波长327nm,柱温30℃。结果:6种绿原酸异构体在0.50~50 mg/L范围内线性关系良好(r>0.9995),检出限1.1~1.5 mg/kg,定量限3.7~5.0 mg/kg;在不同植物样品基质中平均加样回收率93.5%~102%,RSD>3.17%。结论:该方法简便,重复性好,准确度高,可用于植物样品中绿原酸及其异构体的含量测定及产品质量控制。     

基于高效液相色谱法分析烘焙程度对咖啡中绿原酸含量的影响（网络首发、推荐阅读）

探究烘焙程度对10支不同产地（产地一：云南,产地二：非洲,产地三：美洲）卡蒂姆咖啡豆中7种绿原酸化合物含量影响。采用高效液相色谱法测定生豆和烘焙豆中绿原酸、新绿原酸、隐绿原酸、异绿原酸A、异绿原酸B、异绿原酸C和5-阿魏酰奎宁酸含量。经响应面法优化7种绿原酸化合物的最佳提取条件为100 mL 0.1%磷酸溶液沸水浴提取30 min,7种绿原酸化合物在2~150 mg/L质量浓度范围内,线性相关系数良好,相关系数均大于0.999 4,方法检出限0.005~0.500 mg/g,定量限0.02~2.00 mg/g,咖啡生豆中绿原酸的含量最高,其次是5-阿魏酰奎宁酸。随着烘焙程度增加,绿原酸和5-阿魏酰奎宁酸含量显著降低（P<0.05）,新绿原酸和隐绿原酸含量先升高再降低,异绿原酸A的降解速度明显高于异绿原酸B和异绿原酸C,绿原酸、5-阿魏酰奎宁酸的降解速度与其余5种绿原酸相比,较为稳定。通过对不同烘焙程度下7种绿原酸化合物含量变化的研究,可以进一步针对咖啡绿原酸功效成分进行评价,为咖啡烘焙和品质控制提供参考依据。     

龟苓膏中绿原酸含量测定及衰减跟踪监测

提出了高效液相色谱法测定龟苓膏中绿原酸含量的方法.样品经50％甲醇超声提取,以Gemini-C18色谱柱(250 mmnx4.60mm,5μm)为分离柱,以甲醇-0.4％瞵酸溶液(22:78)为流动相,用紫外检测器于327nm处检测,外标法定量.方法检出限为0.05μg/mL,加标回收率为97％,相对标准偏差(n=6)...     

反相高效液相色谱法测定山楂中绿原酸的含量

本实验中运用反相高效液相色谱对山楂中的有效成分绿原酸进行了分离,并对其进行了含量测定,建立了反相HPLC测定山楂中绿原酸含量的方法。色谱柱:KromasilC18(250mm×4.6mm,5μm),流动相:乙腈-水-甲酸(9:91:0.1),流速:0.8ml/min,检测波长:327nm,柱温:35℃。加样回收率为98.2%,RSD为0.80%。     

Characterization of Chlorogenic Acids in Coffee by Flow-Through Chronopotentiometry

In this study, flow-through chronopotentiometry (FTCP) has been developed as an electroanalytical method for characterization (identification and quantification) of chlorogenic acids (CGAs) in coffees. The characterization of CGAs in coffee was based on the electrochemical behavior of the main chlorogenic acid (CGAs) isomers presented in coffee (caffeoylquinic acids (CQAs), dicaffeoylquinic acids (diCQAs), and feruloylquinic acids (FQAs)) and the spiking of CGAs standards in coffee samples. The FTCP study has shown that electrochemical properties of CGAs strongly depend on their chemical structure and electronic properties, particularly on the presence of electron-donating ?OH, ?CH═CH? and ?OCH₃ groups and strong electron-withdrawing ester (?COOR) group presented in their structure. The FTCP measurements of coffee samples show that their electrochemical behavior is very similar to that of CGAs. Therefore, FTCP can be used for characterization of CGAs and determination of their content in coffees. 5-O-Caffeoylquinic acid (5-CQA), prevailed CGAs in coffees, was used as a standard for quantification of total CGA content in coffee. The linear calibration curve of 5-CQA was observed within the concentration range of 5 to 100 μmol L^?1 with the limit of detection 5.7·10^?7 mol L^?1. The total CGA content of coffees has been expressed in 5-CGA equivalents per 100 g of coffee. It was shown that FTCP is a very sensitive, precise, and acurate method for determination of total CGA content in coffee. It should be noted that in presented investigation, FTCP was for the first time used for the study of electrochemical properties of polyphenolic antioxidants (including CGAs) and their characterization in some of the food samples.     

甜叶菊毛状根培养系统的建立及绿原酸类成分的诱导

本文利用发根农杆菌A4诱导甜叶菊毛状根再生,建立毛状根生产绿原酸类物质的培养体系,并研究茉莉酸甲酯和水杨酸对毛状根中绿原酸类物质积累的影响。结果表明,经发根农杆菌A4侵染的甜叶菊叶片外植体在共培养14 d后诱导出了毛状根;PCR检测结果表明,发根农杆菌Ri质粒中rolB和rolC基因均已整合到毛状根中;毛状根在MS液体培养基中,培养到第14 d时分别加入不同浓度（50、100、200 μmol/L）的水杨酸和茉莉酸甲酯进行诱导,处理第1、3、6 d后均抑制了毛状根的生长,但茉莉酸甲酯促进了毛状根中绿原酸类物质的积累,而水杨酸却抑制了毛状根中绿原酸类物质的积累。由此说明,发根农杆菌A4侵染甜叶菊可诱导出毛状根,该毛状根可用于绿原酸类物质的生产,茉莉酸甲酯可提高绿原酸类物质的含量。     

咖啡中功能性成分分离检测技术及安全性评价

咖啡以其独特的风味口感以及生理活性成为世界范围内最重要的食品类商品之一。咖啡的生理活性主要来自于咖啡中的咖啡因、绿原酸以及类黑精等功能性成分,这些成分具有醒脑提神、抗忧郁、抗氧化、抗菌以及预防癌症等方面的生物活性。因此,咖啡中功能性成分的分离提取、分析检测以及其安全性评价已经成为目前研究的热点。本文对咖啡中功能性成分咖啡因、绿原酸和类黑精的分离检测技术及其安全性评价研究进展进行综述,为咖啡中功能性成分的分离分析以及科学使用提供前沿的科学参考。