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1.
Four alcohols, 1-penten-3-ol, n-amylalcohol, trans-2-hexenol and one of the linalool oxides, were newly identified as the components of carbonyl-free neutral fraction of the essential oil of black tea.

On the gas chromatogram of carbonyl fraction three unknown peaks were identified with those of n-valeraldehyde, n-heptanal and trans-2-octenal.

From these results almost all main components of carbonyl and carbonyl free fractions were clarified.

Flavor change during the manufacture of black tea was investigated by gas chromatography. During withering, hexylalcohol, nerol, trans-2-hexenoic acid, trans-2-heхenol, linalool oxide (cis, furanoid), n-valeraldehyde, capronaldehyde, n-heptanal, trans-2-hexenal, trans-2-octenal, benzaldehyde, phenylacetaldehyde, n-butyric, isovaleric, n-caproic, cis-3-hexenoic and salicylic acids and o-cresol were increased, especially the former three greatly increased, while cis-2-pentenol, linalool, geraniol, benzylalcohol, phenylethanol and acetic acid diminished markedly. In the process of fermentation almost all constituents increased, especially, 1-penten-3-ol, cis-2-pentenol, benzylalcohol, trans-2-hexenal, benzaldehyde, n-caproic, cis-3-hexenoic and salicylic acids were remarkable.

On firing, most alcohols, carbonyl and phenolic compounds decreased remarkably whereas acetic, propionic and isobutyric acids greatly increased.  相似文献   

2.
To investigate the aroma components characteristic of spring green tea, analysis of the aroma concentrates of green tea and fresh tea-leaves was accomplished. The research on the changes in aroma constituents of spring green tea and the aroma concentrate from fresh tea-leaves during storage, showed that cis-3-hexenylhexanoate and cis-3-hexenyl-trans-2-hexenoate contributed to the typical fresh aroma of spring green tea. Twelve isomers of hexenol esters were synthesized for comparison of the fresh green note.  相似文献   

3.
Acidic fraction of the essential oil of black tea has a characteristic odor and affects the tea flavor. Eight aliphatic acids were identified by gas chromatography with the authentic samples known as the constituents of tea flavor. Two unknown substances were separated and identified as cis-3-hexenoic acid and trans-2-hexenoic acid respectively.

Three kinds of black tea (i.e. Assam, Shan and Benihomare) have same acidic components and the percent composition of these acids is different among them.  相似文献   

4.
Intermediate and high boiling neutral compounds in the aroma concentrate from black tea were isolated by fractional distillation, silica-gel column chromatography and gas chromatography.

Identification of the compounds was verified by the agreement of IR and mass spectra as well as gas chromatographic data with those of authentic compounds.

Eleven compounds; α-muurolene, δ-cadinene, furfuryl alcohol, methyl phenyl carbinol, cadinenol, geranial, pyrrole-2-aldehyde, benzyl formate, phenylethyl formate, cis-3-hexenyl benzoate and indole, were newly identified as constituents of black tea aroma and ten known components; α-terpineol, 3, 7-dimethyl-l, 5, 7-octatrien-3-ol, trans, trans-2, 4-decadienal, 2-phenyl-2-butenal, α- and β-ionone, cis-jasmone, theaspirone, lactone of 2-hydroxy-2, 6, 6-trimethylcyclohexylidene-l-acetic acid and phenylacetonitrile were confirmed. The geometric structure of theaspirone in tea aroma was determined as the cis-form.  相似文献   

5.
The aroma concentrates from Vietnamese green tea and lotus tea were prepared and analyzed. Characterization of the components were carried out using coupled gas chromatography and mass spectrometry and infrared spectrometry, besides gas chromatographic retention data.

Anethole and 1,4-dimethoxybenzene have been identified for the first time as the flavor constituents in green tea. Linalool, two linalooloxides (cis and trans, five membered), 3,7-dimethyl-1,5,7-octatriene-3-ol, 2,5 (or 2,6)-dimethylpyrazine and 1-ethyl-2-formylpyrrole were the predominant components in Vietnamese green tea.

1,4-Dimethoxybenzene has been identified as the main component in lotus tea. The compound was also isolated from both dried and fresh lotus pollen.  相似文献   

6.
The constituents of steam volatile aroma, which were responsible for topnote of Ceylon tea aroma, were identified. A total of 57 compounds were identified, of which 10 (ter-pinolene, n-nonanal, trans-2-pentenal, trans-3-octen-2-one, 6-methyl-3,5-heptadien-2-one, n-nonanol, cis-3-hexenylbutyrate, cis-3-hexenylcaproate, α-terpinylacetate and nerylacetate) had not previously been reported as associated with aroma of black tea. Approximate composition of topnote aroma from Ceylon flavory tea was also determined.  相似文献   

7.
The neutral fraction of the essential oils from three kinds of black tea (same samples as described in the previous paper,1) i.e., Assam, Shan and Benihomare) was separated into carbonyl and carbonyl-free fractions and analysed by gas chromatography. On the basis of relative retentions and aroma of effluents with the references of the chromatographic data obtained by the previous works,2–4) the major alcohols were found to be cis-2-pentenol, n-hexanol, cis-3-hexen-1-ol, three isomers of linalooloxide, linalool, nerol, geraniol, benzylalcohol, and phenylethylalcohol. In the carbonyl fraction, phenylacetaldehyde was newly identified, and besides it, the presence of iso- and n-butyr-, iso- and n-valer- aldehyde, methylethylketone, trans-2-hexenal, benzaldehyde were recognized. There were no differences in the components among three kinds of black tea, but the relative quantity of each component in the essential oil was different among three varieties.  相似文献   

8.
The first effluent of essential oil of black tea in the gas chromatographic analysis is important for characterizing black tea flavor. The isolation and identification of main unknown components were conducted by means of gas chromatography, and also by infrared spectra and ultraviolet spectra. Ethylacetate, ethylalcohol and β-myrcene were identified as the increasing compounds during fermentation. cis-β-Ocimene and trans-β-ocimene were also identified only in completely manufactured black tea. These three terpenoid hydrocarbons are newly found constituents of essential oil of black tea and are supposed to contribute considerably to the black tea flavor.  相似文献   

9.
The enzyme system producing cis-3-hexenal, a precursor of cis-3-hexenol(leaf alcohol) and trans-2-hexenal (leaf aldehyde), from linolenicacid showed high activity in summer and no activity in winterin tea (Thea sinensis) leaves and isolated chloroplasts. Theenzyme system producing n-hexanal from linoleic acid also showedsimilar seasonal changes in activity. These changes were closelyrelated to temperature and solar radiation. Enzyme activitycould not be induced after the leaves had been cut and was notaccompanied by de novo protein synthesis. (Received July 9, 1976; )  相似文献   

10.
Fresh tea leaves were homogenized in a chloroform-methanol mixture (1:1, v/v), and separated into chloroform-soluble and methanol-water-soluble fractions after addition of water. From the chloroform-soluble fraction, the volatile forms of the aroma compounds were obtained. The non-volatile forms of the aroma compounds were associated with the methanol-water-soluble fraction, and were converted to volatile forms by hydrolysis with dilute acid.

The amount of the aroma compounds in the free form, such as cis-3-pentenol, hexanol, cis-3-hexenol, trans-2-hexenol, linalool, linalool oxide (cis, 5-membered), linalool oxide (trans, 5-membered), linalool oxide (trans, 6-rnembered), linalool oxide (cis, 6-membered), nerol, geraniol, phenylmethanol, and 2-phenylethanol, markedly increased during black tea manufacture. However, those in the bound form, showed a slight decrease during the manufacture. The increases in the former were also brought about by maceration, or treatment of the tea leaves with monoiodoacetate or malonate.  相似文献   

11.
The main aroma components of oolong and black tea, linalool and four diastereomers of linalool oxides (LOs), were enantioselectively isolated by capillary gas chromatography, using a column coated with an optically active liquid phase, permethylated β-cyclodextrin.

The R/S ratio varied among linalool and LOs, and among the different types of tea, the ratio for a particular compound also being different. However, the complete patterns of R/S ratio were similar in the semi-fermented and fermented teas, respectively.

Using a specific cultivar of black tea, the R/S ratio for each of the five compounds was compared in the free state in black tea with that of an aglycone of the glycoside in fresh tea leaves or in black tea. While the e.e. values of the compounds varied, those for a specific compound were similar, except for linalool, regardless of their free or combined state.

These results show that LOs are not directly transformed from linalool, but are formed enzymatically from glycoside precursors.  相似文献   

12.
Selenium-enriched tea was suggested as a possible source of supplemental Se. The result of this study indicates that it is not practicable to make selenium-enriched tea as a beverage like traditional green tea or black tea for the supplementation of selenium in human diet. The selenium dispersibilities of fresh tea leaves, green tea, and black tea highly correlated with those of protein (r 2 = 0.998). The high protein dispersibility (85.0%) of fresh tea leaves in water solution was accompanied by that of selenium (93.8%). Decreases in protein dispersibility of green tea and black tea to 2.5% and 4.2 % coincided with those of selenium to only 8.3% and 10.1%, respectively. The amount (14.90 μg) of selenium in saturated ammonium sulphate (a protein precipitating reagent) precipitate was 83.8% of that (17.79 μg) in fresh tea leaf extract, and after the saturated ammonium sulphate precipitate was dialyzed against distilled water overnight, the amount (14.37 μg) of selenium remaining in the dialyzed precipitate (protein) was still 80.8% of that in the fresh tea leaf extract. However, there were no significant differences (p > 0.05) between the amount of selenium in the saturated ammonium sulphate precipitate and that in the saturated ammonium sulphate precipitate that was dialyzed.  相似文献   

13.
ABSTRACT

Awa-bancha is a post-fermented tea produced in Naka and Kamikatsu, Tokushima, Japan. We investigated the lactic acid bacteria in each stage of production of Awa-bancha and evaluated the relationships with the components. Lactic acid bacteria were isolated from tea leaves cultured with de Man, Rogosa, and Sharpe (MRS) agar plates, and the species were identified by homology of the 16 S rRNA gene and multiplex polymerase chain reaction (PCR) of the recA gene to distinguish the Lactobacillus plantarum group. As a result, a variety of species were isolated from the raw tea leaves, and Lactobacillus pentosus was isolated most frequently after anaerobic fermentation. Regarding the tea leaf components, organic acids, such as lactic acid, increased, free amino acids decreased, and catechins changed owing to anaerobic fermentation. Our results suggest that the microbial flora mainly composed of L. pentosus is important in the anaerobic fermentation process for flavor formation of Awa-bancha.  相似文献   

14.
By continuing flavor analysis of green tea from a previous paper, further twenty seven compounds were newly identified. These compounds are limonene, α-cubebene, α-copaene, caryophyllene, α-humulene, α- and γ-muurolene, β-sesquiphellandrene, δ-cadinene, calamenene, cubenol, α-cadinol, α-terpineol, n-heptanol, n-nonanol, furfurylalcohol, n-nonanal, N-ethylformylpyrrole, pyrrylmethylketone, 6-methyl-trans-3,5-heptadien-2-one, 2′,2″-dihydro-α-ionone, 6,10,14-trimethyl-2-pentadecanone, cis-3-hexenylcaproate, cis-3-hexenylbenzoate, α-terpinylacetate, coumarin and diphenylamine.

Relative quantities of known compounds in intermediate- and high-boiling fraction were determined.  相似文献   

15.
Leaf Alcohol     
Successful oxidations with chromic acid-sulfuric acid mixture of synthetic isomeric hex-2-en-l-ols to give trans-hex-2-en-l-al (leaf aldehyde) and the failure of those of synthetic isomeric hex-3-en-l-ols pointed out the probable contamination of the 2-enol isomer in the earlier “leaf alcohol preparation” of plant origin, which might lead the workers to an erroneous conclusion.

In support of the present worker’s opinion, trans-hex-2-en-l-ol was actually isolated from fresh tea leaves and identified in the present investigation and a mechanistic rational was invoked to account for the results of oxidations of isomeric n-hexenols.  相似文献   

16.
Thea sinensis; Theaceae; tea; cis-3-hexenal: leaf aldehyde; leaf alcohol; linolenic acid; biosynthesis of leaf alcohol.Linolenic acid and cis-3-hexenal were found in macerated leaves of Thea sinensis and this aldehyde may be produced from linolenic acid by an enzyme contained in macerated leaves in the presence of oxygen. This aldehyde was easily isomerized to trans-2-hexenal, and was converted to cis-3-hexenol by alcohol dehydrogenase. During maceration of freshly picked tea leaves, the amounts of trans-2-hexenal quickly increased and were influenced by maceration time, heating, oxygen and the pH. But in unpicked tea leaves the occurrence of trans-2-hexenal is extremely doubtful.  相似文献   

17.
The ester and lactone fraction possessing the most attractive aroma was separated from the aroma concentrate of Ceylon flavory tea by silica-gel column chromatography and analyzed by GC-MS.

Methyl 2-(cis-2′-pentenyl)-cyclopentanone-3-acetate(methyl jasmonate), 5-(cis-2′-pentenyl)-5-pentanolide (jasmine lactone), 2,3-dimethyl-2-nonen-4-olide, 4-octanolide, 4-nonanolide and 5-decanolide were newly identified as the constituents of tes aroma. Former two compounds seemed to carry a major share of aroma character of Ceylon flavory tea.  相似文献   

18.
滕杰  曾贞  黄亚辉 《广西植物》2018,38(5):568-576
该研究采用分光光度法和高效液相色谱法,分不同叶位对秃房茶(Camellia gymnogyna)的嘌呤生物碱组成特点以及茶多酚、儿茶素组分、游离氨基酸、黄酮、茶氨酸等生化品质成分进行了测定。结果表明:秃房茶的嘌呤生物碱组成及配比显著区别于茶叶植物凤凰单从(C.sinensis),同时具有可可碱、咖啡碱和苦茶碱三种组分,而且可可碱含量最多,为13.46~39.72 mg·g~(-1),咖啡碱含量最低,为0.51~2.02 mg·g~(-1),苦茶碱含量介于两者中间并随芽叶成熟度增加而升高。茶叶植物只存在咖啡碱和可可碱,含量变化分别为22.22~53.13 mg·g~(-1)和0.47~12.82 mg·g~(-1)。在相同叶位中,秃房茶儿茶素组分含量变化规律为EGCGCECGEGCECGCCGGCG,且儿茶素总量、酯型儿茶素含量均低于茶叶植物,而非酯型儿茶素总量接近,保持为40~50 mg·g~(-1)。除黄酮含量在各叶位变化趋势不大外,其他品质成分含量变化基本符合第1叶芽第2叶第3叶第4叶,一芽二叶的含量介于第1叶和第2叶之间的规律,而茶多酚、黄酮、茶氨酸等其它品质成分含量均低于茶叶植物。该研究首次明确了秃房茶主要生化品质成分变化规律,特别是嘌呤生物碱的组成及配比特点,且含有特征性成分—苦茶碱。该研究结果为生物碱代谢机理、特异茶加工、功能成分开发、低咖啡碱资源、选育种等提供了优良材料。  相似文献   

19.
Abstract

An in vitro study was conducted to determine the effect of different types of fibre supplemented with sunflower oil on ruminal fermentation and formation of conjugated linoleic acids (CLA) by mixed ruminal microorganisms. Cell wall components extracted from wheat straw (representing lignified fibre), soybean hulls (representing easily digestible fibre), and purified cellulose were used as substrates. Sunflower oil was supplemented at the same level for all three types of fibre. After 24 h of incubation, ruminal fermentation parameters (including 24 h gas production, pH value, concentration of ammonia nitrogen and volatile fatty acids) and the concentration of long chain fatty acids in the culture fluid were determined. Results showed that the type of fibre influenced ruminal fermentation traits and the biohydrogenation of unsaturated C18 fatty acids in vitro. Composition of LCFA and profile of CLA were altered by the fibre type. Compared to the digestible fibre and purified cellulose, lignified fibre significantly increased the production of cis-9, trans-11 CLA and total CLA (sum of cis-9, trans-11 CLA, trans-10, cis-12 CLA, trans-9, trans-11 CLA, and cis-9, cis-11 CLA) by ruminal microorganisms. It was concluded that ruminal fermentation and production of CLA can be affected by the type of dietary fibre.  相似文献   

20.
Leaf oil samples of four Japanese citrus species were analysed by gas chromatography to determine the detailed composition of each leaf oil. The following components were identified: α-pinene, α-thujene, camphene, β-pinene, sabinene, β-myrcene, α-terpinene, limonene, β-phellandrene, trans-2-hexen-1-al, γ-terpinene, p-cymene, terpinolene, cis-2-penten-1-ol, n-hexyl alcohol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, p-α-dimethylstyrene linalool, linalyl acetate, β-elemene, terpinen-4-ol, caryophyllene, humulene, α-terpineol, neryl acetate, geranyl acetate, β-selinene, geraniol and thymol. Most components were contained in common in leaf oils of the four citrus species, but relative contents of some of the components; such as γ-terpinene, linalyl acetate, and thymol differed from species to species. For example, γ-terpinene was the major component (33.8%) of Hassaku, whereas it was only a minor component in Daidai. Daidai is characterized by a very high content of linalyl acetate (35%) which is only a trace in the other three species. Kishu-mikan is characterized by a high content of thymol (15%).  相似文献   

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