[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) com...[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.展开更多
Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was deve...Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was developed for the determination of organochlorine pesticides(OCPs)in bottled juice drinks using GC-MS.Sample pretreatment was performed using dispersive solid-phase microextraction(D-μ-SPE)for matrix desorption and dispersive liquid-liquid microextraction(DLLME)for analyte enrichment.In this study,an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE.The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analysis.The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME,which made the combination of D-μ-SPE with DLLME much easier.The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME.Then after,the optimal values were determined for the real sample analysis.Accordingly,there was good linear dynamic range with a coefficient of determination(r2)≥0.9989.The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively.The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100%.Intraday and interday precisions were≤4%.Compared with other reported methods,this method is a one-step,simple,cheap,fast,and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions.These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples.展开更多
采用液液萃取(liquid-liquid extraction,LLE)和顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometr...采用液液萃取(liquid-liquid extraction,LLE)和顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOFMS)技术解析了天龙泉米香型白酒挥发性组分特征。采用该技术并结合多种检索比对方式在天龙泉米香型白酒中鉴定出挥发性化合物505种,其中339种为天龙泉米香型白酒的潜在香气活性组分,包括86种酯类、50种芳香族、42种醇类、40种醛类、32种含氧杂环化合物、30种酮类、25种萜烯类、19种有机酸类、11种含硫化合物和4种含氮杂环化合物,表明了米香型白酒中香气成分的多样性和复杂性。在挥发性香气化合物含量角度上,不同贮存期的米香型白酒样品呈现明显差异,在时间维度上具有一定规律。其中,变化较大的化合物是醇类化合物、酯类化合物和醛类化合物,可能是受到了企业生产工艺的调整和陈化过程中发生的化学反应共同影响。该研究更深入地认识了米香型白酒的挥发性风味物质,丰富了米香型白酒风味化学的研究体系。展开更多
为探究汽蒸前后六堡茶风味品质和挥发性物质的差异,采用感官评价和顶空固相微萃取(headspace solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time of flight...为探究汽蒸前后六堡茶风味品质和挥发性物质的差异,采用感官评价和顶空固相微萃取(headspace solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time of flight mass spectrometry,GC×GC-TOF-MS)对汽蒸前后六堡茶进行分析。结果表明,汽蒸能够有效提升六堡茶品质,汤色由橙色、较亮转变为橙红明亮,滋味方面酸味、涩味以及醇厚感得到有效改善,香气方面汽蒸后堆味、豆豉味等不利于六堡茶品质的气味得到有效去除,发酵气也得到减弱;分别从汽蒸前后六堡茶中检测出189种和188种挥发性化合物,碳氢类化合物最多,其次为醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、含氮类、内酯类和酚类化合物。T检验分析表明,汽蒸前后六堡茶中碳氢类、醛类、呋喃类和酚类化合物总含量无显著差异(p>0.05);内酯类和含氮类化合物的总含量显著降低(p<0.05);醇类、酮类、酯类和甲氧基苯类的总含量极显著降低(p<0.01),其中碳氢类、醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、酚类、内酯类和含氮类化合物中差异显著(p<0.05)的化合物分别有10、3、3、5、2、1、2、0、2种和1种;差异极显著(p<0.01)的化合物分别有32、24、11、4、14、6、6、1、2种和4种。展开更多
为探究油炸对牦牛肉风味物质及品质的影响,对不同油炸温度和时间下的牦牛肉进行感官评分、水分含量、色差值、质构指标的测定;采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid phase microextraction combined with gas chro...为探究油炸对牦牛肉风味物质及品质的影响,对不同油炸温度和时间下的牦牛肉进行感官评分、水分含量、色差值、质构指标的测定;采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid phase microextraction combined with gas chromatography-mass spectrometry,HS-SPME-GC-MS)分析油炸前后牦牛肉风味物质的种类和含量变化。结果表明:E_2组(160℃、80 s)牦牛肉感官评分、色差值、质构品质指标均最优。HS-SPME-GC-MS共鉴定出41种挥发性风味物质,包括醛类20种、醇类5种、酯类2种、酮类1种、呋喃类1种、烃类7种、有机酸类1种、其它类4种化合物;A组(参照组)检测出27种化合物,E_2组检测出38种化合物,两组牦牛肉中挥发性成分种类及相对含量有较大差异。根据香气特征雷达图得出,E_2组的香气种类更丰富。利用相对气味活度值对牦牛肉关键风味成分分析得出,A组关键挥发性风味物质有10种,E_2组关键挥发性风味物质有17种,其中反式-2-癸烯醛、壬醛、1-辛烯-3-醇相对气味活度值最大,分别为47.35、35.14、17.63,赋予油炸牦牛肉烤肉味、果香味、蘑菇香味。通过韦恩图得出,A组特有的挥发性风味物质有3种,E_2组特有的挥发性风味物质有14种,A组特有关键香气成分2种,E_2组特有关键香气成分9种。综合风味指标、质构指标和感官评价指标得出,油炸工艺对牦牛肉的风味及品质有明显提升。展开更多
基金Supported by Key Science and Technology Project of Gansu Province(1302NKDA028)Science and Technology Planning Project of Lanzhou(2010-1-239+2 种基金 2016-3-4)Talent Project of Lanzhou Science and Technology Bureau(2015-RC-87)Project of Science and Technology Cooperation between Gansu Academy of Agricultural Sciences and Local Areas(2017GAAS63)
文摘[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.
基金This work was financially supported by the College of Natural Sciences,Jimma University through the grand research project(CNS-Chem-11-2020/21-SP1).
文摘Analysis of pesticide residue levels in juice beverages is important to ensure safe consumption and avoid global trade concerns associated to pesticide contaminations.A simple,inexpensive and effective method was developed for the determination of organochlorine pesticides(OCPs)in bottled juice drinks using GC-MS.Sample pretreatment was performed using dispersive solid-phase microextraction(D-μ-SPE)for matrix desorption and dispersive liquid-liquid microextraction(DLLME)for analyte enrichment.In this study,an affordable and effective sorbent for the adsorption of OCPs from juice samples was synthesized from avocado seeds mixed with magnetic precursors for D-μSPE.The ground avocado seeds combined with a magnetic precursor nanocomposite were characterized using various instruments including scanning electron microscopy(SEM),X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),and Brunauer-Emmett-Teller(BET)analysis.The solution obtained from D-μ-SPE desorption was used as a dispersant for the subsequent DLLME,which made the combination of D-μ-SPE with DLLME much easier.The effectiveness of the method was enhanced by optimizing the influential parameters in both D-μ-SPE and DLLME.Then after,the optimal values were determined for the real sample analysis.Accordingly,there was good linear dynamic range with a coefficient of determination(r2)≥0.9989.The limit of detection and quantification were 0.02–0.69 and 0.06–2.10 ng/L respectively.The method showed high enrichment factors ranging from 96 to 313 with recoveries of 87–100%.Intraday and interday precisions were≤4%.Compared with other reported methods,this method is a one-step,simple,cheap,fast,and environmentally friendly alternative and straightforward method for adsorbing organochlorine pesticides from sample solutions.These results demonstrates the high potential of the proposed method for the extraction and cleanup of contaminants in selected juices and other related samples.
文摘采用液液萃取(liquid-liquid extraction,LLE)和顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry,GC×GC-TOFMS)技术解析了天龙泉米香型白酒挥发性组分特征。采用该技术并结合多种检索比对方式在天龙泉米香型白酒中鉴定出挥发性化合物505种,其中339种为天龙泉米香型白酒的潜在香气活性组分,包括86种酯类、50种芳香族、42种醇类、40种醛类、32种含氧杂环化合物、30种酮类、25种萜烯类、19种有机酸类、11种含硫化合物和4种含氮杂环化合物,表明了米香型白酒中香气成分的多样性和复杂性。在挥发性香气化合物含量角度上,不同贮存期的米香型白酒样品呈现明显差异,在时间维度上具有一定规律。其中,变化较大的化合物是醇类化合物、酯类化合物和醛类化合物,可能是受到了企业生产工艺的调整和陈化过程中发生的化学反应共同影响。该研究更深入地认识了米香型白酒的挥发性风味物质,丰富了米香型白酒风味化学的研究体系。
文摘为探究汽蒸前后六堡茶风味品质和挥发性物质的差异,采用感官评价和顶空固相微萃取(headspace solid phase microextraction,HS-SPME)结合全二维气相色谱-飞行时间质谱(comprehensive two-dimensional gas chromatography-time of flight mass spectrometry,GC×GC-TOF-MS)对汽蒸前后六堡茶进行分析。结果表明,汽蒸能够有效提升六堡茶品质,汤色由橙色、较亮转变为橙红明亮,滋味方面酸味、涩味以及醇厚感得到有效改善,香气方面汽蒸后堆味、豆豉味等不利于六堡茶品质的气味得到有效去除,发酵气也得到减弱;分别从汽蒸前后六堡茶中检测出189种和188种挥发性化合物,碳氢类化合物最多,其次为醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、含氮类、内酯类和酚类化合物。T检验分析表明,汽蒸前后六堡茶中碳氢类、醛类、呋喃类和酚类化合物总含量无显著差异(p>0.05);内酯类和含氮类化合物的总含量显著降低(p<0.05);醇类、酮类、酯类和甲氧基苯类的总含量极显著降低(p<0.01),其中碳氢类、醇类、酮类、醛类、甲氧基苯类、酯类、呋喃类、酚类、内酯类和含氮类化合物中差异显著(p<0.05)的化合物分别有10、3、3、5、2、1、2、0、2种和1种;差异极显著(p<0.01)的化合物分别有32、24、11、4、14、6、6、1、2种和4种。
文摘为探究油炸对牦牛肉风味物质及品质的影响,对不同油炸温度和时间下的牦牛肉进行感官评分、水分含量、色差值、质构指标的测定;采用顶空固相微萃取-气相色谱-质谱联用技术(headspace solid phase microextraction combined with gas chromatography-mass spectrometry,HS-SPME-GC-MS)分析油炸前后牦牛肉风味物质的种类和含量变化。结果表明:E_2组(160℃、80 s)牦牛肉感官评分、色差值、质构品质指标均最优。HS-SPME-GC-MS共鉴定出41种挥发性风味物质,包括醛类20种、醇类5种、酯类2种、酮类1种、呋喃类1种、烃类7种、有机酸类1种、其它类4种化合物;A组(参照组)检测出27种化合物,E_2组检测出38种化合物,两组牦牛肉中挥发性成分种类及相对含量有较大差异。根据香气特征雷达图得出,E_2组的香气种类更丰富。利用相对气味活度值对牦牛肉关键风味成分分析得出,A组关键挥发性风味物质有10种,E_2组关键挥发性风味物质有17种,其中反式-2-癸烯醛、壬醛、1-辛烯-3-醇相对气味活度值最大,分别为47.35、35.14、17.63,赋予油炸牦牛肉烤肉味、果香味、蘑菇香味。通过韦恩图得出,A组特有的挥发性风味物质有3种,E_2组特有的挥发性风味物质有14种,A组特有关键香气成分2种,E_2组特有关键香气成分9种。综合风味指标、质构指标和感官评价指标得出,油炸工艺对牦牛肉的风味及品质有明显提升。
