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1.
Volatile compounds were isolated from Costa Rican guava fruit by simultaneous steam distillation-solvent extraction according to the Likens-Nickerson method. Compounds were identified by capillary GC-MS and sensorially characterized by sniffing-GC. One hundred and seventy-three components were identified in the aroma concentrate, from which (E)-beta-caryophyllene, alpha-terpineol, alpha-pinene, alpha-selinene, beta-selinene, delta-cadinene, 4,11-selinadiene, and alpha-copaene were found to be the major constituents. The amounts of aliphatic esters and terpenic compounds were thought to contribute to the unique flavor of this fruit. 相似文献
2.
Flavor characteristics of lapsang souchong and smoked lapsang souchong, a special Chinese black tea with pine smoking process 总被引：1，自引：0，他引：1
The major volatile constituents of lapsang souchong, smoked lapsang souchong, and smoked souchong, a group of special black teas in China, were analyzed with GC and GC-MS analyses. Forty-nine constituents were identified. Longifolene and alpha-terpineol were the most abundant compounds in the aroma. Due to its special production process, the compounds longifolene, longicyclene, guaiacol, 4-methylguaiacol, 4-ethylguaiacol, etc., were identified only in this kind of black tea. The aroma constituents of tea origin decreased during the smoking process, whereas the pine terpenoids and the thermal pyrolysis products of the pine wood increased markedly. The pine material for smoking was also analyzed for the volatile constituents showing apparent selectivity of the tea leaves to absorb. There were apparent differences among the tea samples in the contents of aroma constituents. The characteristics of the aroma of the teas are discussed with their processes and the features of sensory qualities. 相似文献
3.
Koukos PK Papadopoulou KI Patiaka DT Papagiannopoulos AD 《Journal of agricultural and food chemistry》2000,48(4):1266-1268
The composition of essential oils from twigs and needles of Balkan pine (Pinus peuce Gris.) grown in northern Greece was investigated. The compounds were identified by using GC-MS analysis. The twig oil was rich in alpha-pinene (7.38%), beta-pinene (12.46%), beta-phellandrene (26.93%), beta-caryophyllene (4.48%), and citronellol (12.48%), and the needle oil was rich in alpha-pinene (23.07%), camphene (5.52%), beta-pinene (22.00%), beta-phellandrene (6.78%), bornyl acetate (9.76%), beta-caryophyllene (3.05%), and citronellol (13.42%). The mean oil yield was 2.85% for twigs and 0. 57% for needles. 相似文献
4.
5.
Volatile compounds were isolated from four cultivars of bullock's heart fruit (Cenizo, Rojo, Verde, and De Ojo) by simultaneous steam distillation-solvent extraction. Compounds were identified by HRGC and capillary GC-MS. One hundred and eighty compounds were identified in the aroma extracts, of which alpha-pinene, beta-pinene, myrcene, limonene, terpinen-4-ol, and germacrene D were found to be the major constituents. Fruit from cv. De Ojo containing the highest concentration of total volatile and the highest major terpenoid content had the highest custard-like and overall fruity aroma intensity. The presence of many terpenic compounds is thought to contribute to the unique flavor of the bullock's heart fruit. 相似文献
6.
Naef R Jaquier A Velluz A Maurer B 《Journal of agricultural and food chemistry》2006,54(24):9201-9205
The volatile constituents of two exquisite green tea varieties, Kiyosawa tea from Japan and Long Jing tea from China, were investigated in order to identify new compounds responsible for the characteristic flavor of a green tea brew. The extracts were prepared by solid-phase extraction using Oasis-HLB-cartridges. Besides the common compounds of green tea chemistry, the already described compounds 3-methyl-2,4-nonanedione (1) and 3-hydroxy-3-methyl-2,4-nonanedione (2), products of degradation of furan fatty acids, as well as three new compounds related to compound 1 were identified. These were 1-methyl-2-oxopropyl hexanoate (3), 1-methyl-2-oxoheptyl acetate (4) and 2-butyl-4,5-dimethyl-3(2H)-furanone (5). Their syntheses and spectroscopic data are reported. Compound 2 increases the sweet, creamy aroma and the characteristic mouthfeel of a green tea flavor, compounds 3 and 4 contribute to its floral, juicy notes and compound 5 exhibits an interesting sweet, buttery flavor. 相似文献
7.
Ito Y Sugimoto A Kakuda T Kubota K 《Journal of agricultural and food chemistry》2002,50(17):4878-4884
The odorants in Chinese jasmine green tea scented with jasmine flowers (Jasminum sambac) were separated from the infusion by adsorption to Porapak Q resin. Among the 66 compounds identified by GC and GC/MS, linalool (floral), methyl anthranilate (grape-like), 4-hexanolide (sweet), 4-nonanolide (sweet), (E)-2-hexenyl hexanoate (green), and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (sweet) were extracted as potent odorants by an aroma extract dilution analysis and sensory analysis. The enantiomeric ratios of linalool in jasmine tea and Jasminum sambac were determined by a chiral analysis for the first time in this study: 81.6% ee and 100% ee for the (R)-(-)-configuration, respectively. The jasmine tea flavor could be closely duplicated by a model mixture containing these six compounds on the basis of a sensory analysis. The omission of methyl anthranilate and the replacement of (R)-(-)-linalool by (S)-(+)-linalool led to great changes in the odor of the model. These two compounds were determined to be the key odorants of the jasmine tea flavor. 相似文献
8.
Yanagimoto K Ochi H Lee KG Shibamoto T 《Journal of agricultural and food chemistry》2003,51(25):7396-7401
Antioxidative activities of volatile extracts from six teas (one green tea, one oolong tea, one roasted green tea, and three black teas) were investigated using an aldehyde/carboxylic acid assay and a conjugated diene assay. The samples were tested at levels of 20, 50, 100, and 200 micrograms/mL of dichloromethane. The results obtained from the two assays were consistent. All extracts except roasted green tea exhibited dose-dependent inhibitory activity in the aldehyde/carboxylic acid assay. A volatile extract from green tea exhibited the most potent activity in both assays among the six extracts. It inhibited hexanal oxidation by almost 100% over 40 days at the level of 200 micrograms/mL. The extract from oolong tea inhibited hexanal oxidation by 50% in 15 days. In the case of the extract from roasted green tea, the lowest antioxidative activity was obtained at the level of 200 micrograms/mL, suggesting that the extract from roasted green tea contained some pro-oxidants. The extracts from the three black teas showed slight anti- or proactivities in both assays. The major volatile constituents of green tea and roasted green tea extracts, which exhibited significant antioxidative activities, were analyzed using gas chromatography-mass spectrometry. The major volatile chemicals with possible antioxidative activity identified were alkyl compounds with double bond(s), such as 3,7-dimethyl-1,6-octadien-3-ol (8.04 mg/kg), in the extract from green tea and heterocyclic compounds, such as furfural (7.67 mg/kg), in the extract from roasted green tea. Benzyl alcohol, which was proved to be an antioxidant, was identified both in a green tea extract (4.67 mg/kg) and in a roasted tea extract (1.35 mg/kg). 相似文献
9.
Heat processing during canning is responsible for the change in flavor of black tea infusion. The quantitative change in the volatile components of the black tea infusion during heat processing is not sufficient for explaining the sensory evaluation. In this study, application of aroma extract dilution analysis using the volatile fraction before and after black tea (Darjeeling) samples were heat processed resulted in the detection of 10 odor-active peaks for which flavor dilution (FD) factors changed. Seven potent odorants were identified from these peaks by gas chromatography-mass spectrometry. Among these components, 3-methylbutanal (stimulus), methional (potato-like), beta-damascenone (sweet), dimethyl trisulfide (putrid), and 2-methoxy-4-vinylphenol (clove-like) showed the highest FD factors after heat processing of the black tea sample. Therefore, these odorants were the most important components involved in changing the black tea odor during heat processing. In addition, the precursor of beta-damascenone in black tea infusion was investigated, and 3-hydroxy-7,8-didehydro-beta-ionol was determined to be one of the beta-damascenone-generating compounds for the first time. 相似文献
10.
Application of aroma extract dilution analysis on an extract of the dried fruits of the West African peppertree Xylopia aethiopica obtained by extraction with diethyl ether followed by sublimation in vacuo revealed 28 odor-active compounds in the flavor dilution (FD) factor range of 4-8192, all of which could be identified. The highest FD factor was found for linalol (floral), followed by (E)-beta-ocimene (flowery), alpha-farnesene (sweet, flowery), beta-pinene (terpeny), alpha-pinene (pine needle-like), myrtenol (flowery), and beta-phellandrene (terpeny). Vanillin (vanilla-like) and 3-ethylphenol (smoky, phenolic) showing somewhat lower FD factors (FD = 128) were detected for the first time as constituents of the dried fruit. 相似文献
11.
In a black tea (Dimbula) infusion, the potent "sweet and/or juicy" odorants were identified as the cis- and trans-4,5-epoxy-(E)-2-decenals by comparison of their gas chromatography retention indices, mass spectra, and odor quality to those of the actual synthetic compounds. Of the two odorants, cis-4,5-epoxy-(E)-2-decenal has been identified for the first time in the black tea. On the basis of the aroma extract dilution analysis on the flavor distillate obtained using the solvent-assisted flavor evaporation technique from the black tea infusion, these isomers showed higher flavor dilution (FD) factors. The FD factors and concentrations of these odorants in the black tea infusion were observed to be much higher than those from Japanese green tea. In addition, the model studies showed that these odorants were generated from linoleic acid and its hydroperoxides by heating, but the generated amounts of these odorants from linoleic acid were much less than those of its hydroperoxides. It can be assumed from these results that the withering and fermentation, which are characteristic processes during the manufacturing of the black tea, which includes the enzymatic reaction such as lipoxygenase, is one of the most important factors for the formation of the epoxydecenal isomers. 相似文献
12.
By application of the aroma extract dilution analysis on the volatile fraction isolated from a black tea infusion (Darjeeling Gold Selection), vanillin (vanilla-like), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel), 2-phenylethanol (flowery), and (E,E,Z)-2,4,6-nonatrienal (oat-flake-like) were identified with the highest flavor dilution (FD) factors among the 24 odor-active compounds detected in the FD factor range of 4-128. Quantitative measurements performed by means of stable isotope dilution assays and a calculation of odor activity values (OAVs; ratio of concentration to odor threshold in water) revealed, in particular, the previously unknown tea constituent (E,E,Z)-2,4,6-nonatrienal as a key odorant in the infusion and confirmed the important role of linalool and geraniol for the tea aroma. An aroma recombinate performed by the 18 odorants for which OAVs > 1 were determined in their "natural" concentrations matched the overall aroma of the tea beverage. In the black tea leaves, a total of 42 odorants were identified, most of which were identical with those in the beverage prepared thereof. However, quantitative measurements indicated that, in particular, geraniol, but also eight further odorants were significantly increased in the infusion as compared to their concentration in the leaves. 相似文献
13.
红茶与绿茶感官品质与其化学组分的相关性 总被引：6，自引：2，他引：4
对茶叶感官审评分属性与其化学组分的相关性进行探讨,该文以不同等级、产地红茶和绿茶为代表,利用传统感官审评方法鉴定茶叶品质（外形、香气、汤色、滋味和叶底）,并对各品质指标进行相关性分析,筛选出对茶叶品质影响最重要的品质指标,即滋味。在利用尺度评价法对茶叶滋味品质的10个分属性（浓度、厚度、甘度、鲜度、醇度、涩度、嫩度、陈味、纯正度、火工度）进行更为细致的评定和对茶叶中主要呈味物质—茶多酚、咖啡碱、茶氨酸进行定量分析的基础上,对不同等级、不同产地茶叶的滋味分属性进行差异分析,并对化学组分与滋味分属性进行相关性分析,结果表明,各种茶样之间的产地和等级间差异主要是鲜度和涩度,而与之相关的组分主要是茶氨酸和咖啡碱,茶多酚的影响还有待进一步考察。该研究实现了茶叶感官品质的定量分析,提高了感官审评结果的客观性和确定性,为茶叶原产地保护和分等分级提供核心技术和标准支撑。 相似文献
14.
Application of aroma extract dilution analysis using the volatile fraction of a Japanese green tea (Sen-cha) sample resulted in the detection of 36 odor-active peaks with flavor dilution (FD) factors between 10 and 5000. Thirty-six potent odorants were identified from 36 odor-active peaks by gas chromatography/mass spectrometry (GC/MS) and/or the multidimensional GC/MS (MDGC/MS) system. Among these components, 4-methoxy-2-methyl-2-butanethiol (meaty), (Z)-1, 5-octadien-3-one (metallic), 4-mercapto-4-methyl-2-pentanone (meaty), (E,E)-2,4-decadienal (fatty), beta-damascone (honey-like), beta-damascenone (honey-like), (Z)-methyl jasmonate (floral), and indole (animal-like) showed the highest FD factors. Therefore, these odorants were the most important components of the Japanese green tea odor. In addition, 4-methoxy-2-methyl-2-butanethiol, 4-mercapto-4-methyl-2-pentanone, methional, 2-ethyl-3, 5-dimethylpyrazine, (Z)-4-decenal, beta-damascone, maltol, 5-octanolide, 2-methoxy-4-vinylphenol, and 2-aminoacetophenone were newly identified compounds in the green tea. 相似文献
15.
Volatile compounds were isolated from strawberry guava fruit by simultaneous steam distillation-solvent extraction according to Likens-Nickerson. Compounds were identified by capillary GC-MS and sensorially characterized by sniffing GC. Two hundred and four compounds were identified in the aroma concentrate, of which ethanol, alpha-pinene, (Z)-3-hexenol, (E)-beta-caryophyllene, and hexadecanoic acid were found to be the major constituents. The presence of many aliphatic esters and terpenic compounds is thought to contribute to the unique flavor of the strawberry guava fruit. 相似文献
16.
Identification of the astringent taste compounds in black tea infusions by combining instrumental analysis and human bioresponse 总被引：4，自引：0，他引：4
Application of taste dilution analyses on freshly prepared black tea infusions revealed neither the high molecular weight thearubigen-like polyphenols nor the catechins and theaflavins, but a series of 14 flavon-3-ol glycosides as the main contributors to the astringent taste perceived upon black tea consumption. Among these glycosides, the apigenin-8-C-[alpha-l-rhamnopyranosyl-(1-->2)-O-beta-d-glucopyranoside] was identified for the first time in tea infusions. Depending on the structure, the flavon-3-ol glycosides were found to induce a velvety and mouth-coating sensation at very low threshold concentrations, which were far below those of catechins or theaflavins; for example, the threshold of 0.001 micromol/L found for quercetin-3-O-[alpha-l-rhamnopyranosyl-(1-->6)-O-beta-d-glucopyranoside] is 190000, or 16000 times below the threshold determined for epigallocatechin gallate or theaflavin, respectively. Moreover, structure/activity considerations revealed that, besides the type of flavon-3-ol aglycon, the type and the sequence of the individual monosaccharides in the glycosidic chain are key drivers for astringency perception of flavon-3-ol glycosides. 相似文献
17.
The volatile components from intact tea shoots (ITS), obtained by air entrainment, were identified by their mass spectra and retention times and confirmed by comparison with standard samples. They are E-2-hexenal, ocimene, Z-3-hexenyl acetate, Z-3-hexen-1-ol, butanoic acid-3-hexenyl ester, linalool, 1-octanol, geraniol, and indole. Volatiles from mechanically pierced tea shoots (MPTS) were identified as E-2-hexenal, ocimene, Z-3-hexen-1-ol, butanoic acid-3-hexenyl ester, linalool, geraniol, indole, E-2-hexenoic acid, Z-3-hexenyl formate, methyl salicylate, and benzyl alcohol, and volatiles from tea aphid-tea shoot complexes (TATSC) were identified as E-2-hexenal, ocimene, Z-3-hexenyl acetate, Z-3-hexen-1-ol, linalool, geraniol, indole, benzaldehyde, and E-2-hexenoic acid. Z-3-Hexen-1-ol is the main component in the three different types of volatiles, and the amount of benzaldehyde in TATSC volatiles is very ample. The attraction of the volatiles from ITS, MPTS, and TATSC, and the nine components of TATSC volatiles to the natural enemies, the coccinellid, Coccinella septempunctata, the parasite, Aphidius sp., and the lacewing, Chrysopa sinica, were determined by electroantennogram (EAG) and the wind tunnel bioassay. TATSC volatiles and benzaldehyde elicited much larger EAG responses and stronger upwind flight and arresting behavior from each natural enemy in the wind tunnel than other infochemicals. 相似文献
18.
采用气相色谱-离子迁移谱分析黄大茶加工过程挥发性成分 总被引：1，自引：1，他引：0
茶叶加工对茶叶香气的形成至关重要。为了研究黄大茶加工过程中香气成分的组成及变化规律,采用气相色谱-离子迁移谱(Gas Chromatography-Ion Mobility Spectrometry,GC-IMS)技术对黄大茶加工过程的挥发性成分进行分析。定性分析、鉴定茶叶挥发性成分,构建黄大茶加工过程挥发性成分的差异谱图,并以鉴定的挥发性成分对黄大茶加工过程进行主成分分析。共鉴定出挥发性成分40种,主要有醇类、酮类、醛类、酯类和杂环类化合物。杂环类和醛类化合物是黄大茶挥发性成分的主体部分,且杀青之后,杂环类化合物的含量随着加工过程的进行逐渐增加,醛类化合物的相对含量在初烘之后呈现显著性增加,而醇类及酮类挥发性成分的相对含量在初烘之后显著性降低(P0.05)。具花香的氧化芳樟醇只在初闷之前的样品中得到鉴定,在鲜叶中的含量最高,达21.98%,而1-辛烯-3-酮及苯乙酮只在初烘之后的样品中得到鉴定。通过GC-IMS的指纹图谱可知,苯甲醛、2,5-二甲基呋喃、糠醛及二甲基二硫等挥发性成分构成了经"拉老火"工序的黄大茶的特征峰区域。在一定程度上,主成分分析能够将黄大茶加工过程样品进行区分,表明气相色谱-离子迁移谱分析可为黄大茶加工过程的判别区分提供可能。相较于传统的茶叶挥发性成分检测分析技术,气相色谱-离子迁移谱具有快速、高效、绿色环保的特点。研究结果提供一种新的茶叶挥发性成分的检测分析方法,同时为茶叶加工过程监测及品质控制等提供了一定参考依据和理论基础。 相似文献
19.
Identification of potent odorants in different green tea varieties using flavor dilution technique 总被引：1，自引：0，他引：1
Two kinds of pan-fired green teas (Japanese Kamairi-cha and Chinese Longing tea) were compared with the common Japanese green tea (Sen-cha). Application of the aroma extract dilution analysis (AEDA) using the volatile fraction of the Sen-cha, Kamairi-cha and Longing tea infusions revealed 32, 51, and 52 odor-active peaks with flavor dilution factors between 16 and 1024, respectively. (Z)-1,5-Octadien-3-one (metallic, geranium-like), 4-mercapto-4-methyl-2-pentanone (meaty, black currant-like), methional (potato-like), (E,Z)-2,6-nonadienal (cucumber-like), and 3-methylnonane-2,4-dione (green, fruity, hay-like) showed high flavor dilution factors in all varieties. In addition, 2-acetyl-1-pyrroline (popcorn-like), 2-ethyl-3,5-dimethylpyrazine (nutty), 2,3-diethyl-5-methylpyrazine (nutty), and 2-acetyl-2-thiazoline (popcorn-like) belonged to the most potent odorants only in the pan-fired green teas. Among these odorants, 2-acetyl-1-pyrroline and 2-acetyl-2-thiazoline were identified for the first time among the tea volatiles. 相似文献
20.
Pu-erh tea, a well-known traditional beverage in China, has attracted more attention because of its beneficial health effects and special flavor and taste. Generally, it is believed that Pu-erh tea with a longer preservation period has better quality and taste. Antioxidant activity is one of the major beneficial activities of tea. In this study, a HPLC-DAD-MS coupled with 2,2'-azinobis (3-ethylbenzthiazolinesulfonic acid) diammonium salt (ABTS) assay was employed for identification and quantification of free radical scavengers in different samples of Pu-erh tea. Among 12 main peaks detected in Pu-erh raw tea, 11 compounds were identified as gallic acid, (-)-gallocatechin, (-)-epigallocatechin, (+)-catechin, caffeine, (-)-epicatechin, (-)-epigallocatechingallate, rutin, (-)-epicatechingallate, quercetin-3-glucoside, and kaempferol-3-glucoside by comparison of their UV and MS data with standard compounds or literature data, respectively. The contents of 12 investigated compounds were also determined or estimated using caffeine, (-)-epicatechin, or rutin as standard. ABTS assay showed that 10 out of 12 compounds were free radical scavengers. Their total amount was used as the marker for evaluation of free radical scavenging activities of different Pu-erh teas, which indicated that the activity of different Pu-erh teas varied; Pu-erh raw tea was stronger than the ripe one, and the activity decreased with the increase of preservation period. 相似文献