We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituen...We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS). Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion, HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.展开更多
In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile com...In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100?C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishtin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishtin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.展开更多
The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw R...The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.展开更多
Jiaozi Steamed Bread(JSB)has a unique aroma as a traditional staple food in China.The volatile compounds in JSBwere extracted by simultaneous distillation and extraction(SDE)and headspace solid-phasemicroextraction(HS...Jiaozi Steamed Bread(JSB)has a unique aroma as a traditional staple food in China.The volatile compounds in JSBwere extracted by simultaneous distillation and extraction(SDE)and headspace solid-phasemicroextraction(HS-SPME).These volatile substances were analyzed by gas chromatography-mass spectrometry(GC-MS)and gas chromatographyolfactometry-mass spectrometry(GC-O-MS).The results demonstrated that 61 volatile compounds were identified totally in samples,of which 15 were confirmed as potent aroma compounds with odor active values(OAVs)>1.The 15 potent aroma compounds were ethanol,1-butanol,1-pentanol,1-hexanol,heptanol,1-octen-3-ol,3-methyl-1-butanol,hexanal,heptanal,nonanal,(E)-2-heptenal,benzaldehyde,(E,E)-2,4-decadienal,2-pentylfuran and naphthalene.The SDEmethod had better linearity with coefficients of determination(R2)equal to or higher than 0.9991.Furthermore,the SDE method also achieved lower sensitivity and better repeatability and recovery than HS-SPME.This work provides reference method and parameters for future research on the flavor of JSB for commercial products.展开更多
The volatile compounds emitted from Mosla chinensis Maxim were analyzed by headspace solid-phase micro- extraction （HS-SPME） and headspace liquid-phase microextraction （HS-LPME） combined with gas chromatography-ma...The volatile compounds emitted from Mosla chinensis Maxim were analyzed by headspace solid-phase micro- extraction （HS-SPME） and headspace liquid-phase microextraction （HS-LPME） combined with gas chromatography-mass spectrometry （GC-MS）. The main volatiles from Mosla chinensis Maxim were studied in this paper. It can be seen that 61 compounds were separated and identified. Forty-nine volatile compounds were identified by SPME method, mainly including myrcene, a-terpinene, p-cymene, （E）-ocimene, thymol, thymol acetate and （E）-fl-farnesene. Forty-five major volatile compounds were identified by LPME method, including a-thujene, a-pinene, camphene, butanoic acid, 2-methylpropyl ester, myrcene, butanoic acid, butyl ester, a-terpinene, p-cymene, （E）-ocimene, butane, 1,1-dibutoxy-, thymol, thymol acetate and （E）-fl-farnesene. After analyzing the volatile compounds, multiple linear regression （MLR） method was used for building the regression model. Then the quantitative structure-retention relationship （QSRR） model was validated by predictive-ability test. The prediction results were in good agreement with the experimental values. The results demonstrated that headspace SPME-GC-MS and LPME-GC-MS are the simple, rapid and easy sample enrichment technique suitable for analysis of volatile compounds. This investigation provided an effective method for predicting the retention indices of new compounds even in the absence of the standard candidates.展开更多
[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japon...[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japonica Houtt. were analyzed by the headspace solid-phase microextraction( HS-SPME) combined with GC-MS,and the relative percentage of each component was determined by peak area normalization. [Results] Thirty kinds of volatile components were identified from the leaves and rhizomes of P. japonica Houtt.,mainly including olefins,aromatic hydrocarbons,alkanes and esters. [Conclusions] The volatile components in different parts of P. japonica Houtt. were different,and there may be difference in the medicinal value of volatile components in different parts,thus it is required to take an overall consideration of these differences in the development and utilization of P. japonica Houtt.展开更多
Methyl jasmonate（MeJA） was widely applied in promoting food quality.Aroma is one of the key indicators in judging the quality of tea.This study examined the effect of exogenous MeJA treatment on tea aroma.The aroma ...Methyl jasmonate（MeJA） was widely applied in promoting food quality.Aroma is one of the key indicators in judging the quality of tea.This study examined the effect of exogenous MeJA treatment on tea aroma.The aroma components in black tea prepared from MeJA-treated fresh tea leaves were extracted using headspace solid-phase microextraction（HS-SPME） and were analyzed using gas chromatography-mass spectrometry（GC-MS） and GC-olfactometry（GC-O）.Forty-five volatile compounds were identified.The results revealed that the MeJA-treated black tea had higher levels of terpene alcohols and hexenyl esters than the untreated tea.Moreover,several newly components,including copaene,cubenol,and indole,were induced by the MeJA treatment.The activities of polyphenol oxidase and β-glucosidase in fresh tea leaves changed after the MeJA treatment.Quantitative real-time polymerase chain reaction（qRT-PCR） analysis indicated that the gene expression levels of polyphenol oxidase and β-primeverosidase were upregulated by two and three folds,respectively,by the MeJA treatment（P0.01）; however,the gene expression of β-glucosidase was downregulated to a half level.In general,the aroma quality of the MeJAtreated black tea was clearly improved.展开更多
Forty-eight vinegar samples including white vinegar, rice vinegar and mature vinegar were collected from several markets in Beijing. Butyltin compounds were determined by headspace solid-phase microextraction coupled ...Forty-eight vinegar samples including white vinegar, rice vinegar and mature vinegar were collected from several markets in Beijing. Butyltin compounds were determined by headspace solid-phase microextraction coupled with gas chromatography and flame photometric detector after in situ ethylation with sodium tetraethylborate. Butyltin species were detected in sixteen vinegar samples and ranged from 0.012 to 14.10 lag Sn L 1. The detection rate of white vinegar is higher than that of rice vinegar and mature vinegar. Vinegar samples with relatively high butyltin concentration (〉1.5 μg Sn L-1) were those stored in plastic bags, indicating that the plastic bag was one of the possible sources of butyltin contamination. This was further confirmed by the leaching experiments of three selected plastic bags, and monobutyltin was detected in the leaching solvents. According to the estimation, the average daily intake of total butyltin compounds through vinegar consumption is about 0.04 ng Sn/kg b.w., much lower than the Tolerable Daily Intake (TDI) of 100 ng Sn/kg b.w. set by the European Food Safety Authority (EFSA).展开更多
文摘We have investigated the use of flash evaporation, headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) as sample concentration and preparation techniques for the analysis of volatile constituents present in Houttuynia cordata Thunb. The samples were analyzed by gas chromatography (GC) and identified by mass spectrometry (MS). Comparison studies were performed. It was found that the results obtained between Headspace solid-phase microextraction HS-SPME and SD techniques were in good agreement. Seventy-nine compounds in Houttuynia cordata Thunb were identified by MS. In flash evaporation, thirty-nine compounds were identified. Discrimination in the response for many constituents studied was not observed, which can be clearly observed in SD and HS-SPME techniques. As a conclusion, HS-SPME is a powerful tool for determining the volatile constitutes present in the Houttuynia cordata.
文摘In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100?C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishtin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishtin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.
基金supported by the Agricultural Science and Technology Innovation Program, China (ASTIP)the Building of Modern Agricultural Industry (Bees) R&D Systems in China (NYCYTI-43-KXJ17)
文摘The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.
基金This project was supported by the National Natural Science Foundation of China(No.31701635)the Key Laboratory of Staple Grain Processing,Ministry of Agriculture(No.DZLS201703)the Henan University of Technology High-level Talents Fund(No.2015BS009).
文摘Jiaozi Steamed Bread(JSB)has a unique aroma as a traditional staple food in China.The volatile compounds in JSBwere extracted by simultaneous distillation and extraction(SDE)and headspace solid-phasemicroextraction(HS-SPME).These volatile substances were analyzed by gas chromatography-mass spectrometry(GC-MS)and gas chromatographyolfactometry-mass spectrometry(GC-O-MS).The results demonstrated that 61 volatile compounds were identified totally in samples,of which 15 were confirmed as potent aroma compounds with odor active values(OAVs)>1.The 15 potent aroma compounds were ethanol,1-butanol,1-pentanol,1-hexanol,heptanol,1-octen-3-ol,3-methyl-1-butanol,hexanal,heptanal,nonanal,(E)-2-heptenal,benzaldehyde,(E,E)-2,4-decadienal,2-pentylfuran and naphthalene.The SDEmethod had better linearity with coefficients of determination(R2)equal to or higher than 0.9991.Furthermore,the SDE method also achieved lower sensitivity and better repeatability and recovery than HS-SPME.This work provides reference method and parameters for future research on the flavor of JSB for commercial products.
基金Project supported by the Natural Science Foundation Programof Zhejiang Province （No. Y407308）, the Ministry of Science and Technology of Zhejiang Province （No. 201 OR 10044） and the Sprout Talented Project Program of Zhejiang Province （No. 2008R40G2020019）.
文摘The volatile compounds emitted from Mosla chinensis Maxim were analyzed by headspace solid-phase micro- extraction （HS-SPME） and headspace liquid-phase microextraction （HS-LPME） combined with gas chromatography-mass spectrometry （GC-MS）. The main volatiles from Mosla chinensis Maxim were studied in this paper. It can be seen that 61 compounds were separated and identified. Forty-nine volatile compounds were identified by SPME method, mainly including myrcene, a-terpinene, p-cymene, （E）-ocimene, thymol, thymol acetate and （E）-fl-farnesene. Forty-five major volatile compounds were identified by LPME method, including a-thujene, a-pinene, camphene, butanoic acid, 2-methylpropyl ester, myrcene, butanoic acid, butyl ester, a-terpinene, p-cymene, （E）-ocimene, butane, 1,1-dibutoxy-, thymol, thymol acetate and （E）-fl-farnesene. After analyzing the volatile compounds, multiple linear regression （MLR） method was used for building the regression model. Then the quantitative structure-retention relationship （QSRR） model was validated by predictive-ability test. The prediction results were in good agreement with the experimental values. The results demonstrated that headspace SPME-GC-MS and LPME-GC-MS are the simple, rapid and easy sample enrichment technique suitable for analysis of volatile compounds. This investigation provided an effective method for predicting the retention indices of new compounds even in the absence of the standard candidates.
文摘[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japonica Houtt. were analyzed by the headspace solid-phase microextraction( HS-SPME) combined with GC-MS,and the relative percentage of each component was determined by peak area normalization. [Results] Thirty kinds of volatile components were identified from the leaves and rhizomes of P. japonica Houtt.,mainly including olefins,aromatic hydrocarbons,alkanes and esters. [Conclusions] The volatile components in different parts of P. japonica Houtt. were different,and there may be difference in the medicinal value of volatile components in different parts,thus it is required to take an overall consideration of these differences in the development and utilization of P. japonica Houtt.
基金supported by the National Natural Science Foundation of China(No.31270734)the Construction Project of Modern Agricultural Technology System(No.CARS-23)the Zhejiang Provincial Science and Technology Plan Project(No.2007C12G3020014),China
文摘Methyl jasmonate（MeJA） was widely applied in promoting food quality.Aroma is one of the key indicators in judging the quality of tea.This study examined the effect of exogenous MeJA treatment on tea aroma.The aroma components in black tea prepared from MeJA-treated fresh tea leaves were extracted using headspace solid-phase microextraction（HS-SPME） and were analyzed using gas chromatography-mass spectrometry（GC-MS） and GC-olfactometry（GC-O）.Forty-five volatile compounds were identified.The results revealed that the MeJA-treated black tea had higher levels of terpene alcohols and hexenyl esters than the untreated tea.Moreover,several newly components,including copaene,cubenol,and indole,were induced by the MeJA treatment.The activities of polyphenol oxidase and β-glucosidase in fresh tea leaves changed after the MeJA treatment.Quantitative real-time polymerase chain reaction（qRT-PCR） analysis indicated that the gene expression levels of polyphenol oxidase and β-primeverosidase were upregulated by two and three folds,respectively,by the MeJA treatment（P0.01）; however,the gene expression of β-glucosidase was downregulated to a half level.In general,the aroma quality of the MeJAtreated black tea was clearly improved.
基金support under the National Basic Research Program of China (2009CB421605)National Key Water Program(2009ZX07207-002-03)National Natural Science Foundation of China (20977096)
文摘Forty-eight vinegar samples including white vinegar, rice vinegar and mature vinegar were collected from several markets in Beijing. Butyltin compounds were determined by headspace solid-phase microextraction coupled with gas chromatography and flame photometric detector after in situ ethylation with sodium tetraethylborate. Butyltin species were detected in sixteen vinegar samples and ranged from 0.012 to 14.10 lag Sn L 1. The detection rate of white vinegar is higher than that of rice vinegar and mature vinegar. Vinegar samples with relatively high butyltin concentration (〉1.5 μg Sn L-1) were those stored in plastic bags, indicating that the plastic bag was one of the possible sources of butyltin contamination. This was further confirmed by the leaching experiments of three selected plastic bags, and monobutyltin was detected in the leaching solvents. According to the estimation, the average daily intake of total butyltin compounds through vinegar consumption is about 0.04 ng Sn/kg b.w., much lower than the Tolerable Daily Intake (TDI) of 100 ng Sn/kg b.w. set by the European Food Safety Authority (EFSA).
