• 한국연초학회지
• /
• 제22권2호
• /
• pp.176-183
• /
• 2000

This study was conducted to compare the volatile components of lamina(cutter group) and midrib of flue-cured tobacco leaves by two analytical methods, Curie-Point pyrolysis and Purge & Trap headspace technique. The pyrolysis of lamina and midrib part of tobacco leaves was performed at the temperature of $330^{\circ}C$, $650^{\circ}C$, and $920^{\circ}C$ by Curie-Point Pyrolyzer, and 33 compounds were identified in the pyrolyzates by GC/MSD. The composition of the components identified showed a quite difference between lamina and midrib. However, the amount of the pyrolyzed products from the both of lamina and midrib was increased with temperature increase except that of acetic acid, furfural, and nicotine. The content of phenolic compounds including phenol, 4-methyl phenol, and 3-methyl phenol was higher in midrib than in lamina, while that of furan compounds such as 2,3-dihydrobenzofuran, 5-hydroxymethyl furfural, was high in lamina. Interestingly, acetamide, 2-propenamide and 3-acetoxy pyridine were not defected in the pyrolyzates of lamina. By Purge & Trap headspace technique, 28 volatile components were identified in both lamina and midrib. The composition of the identified compounds and their chromatograpic patterns also showed the complete difference between the two. The content of solanone, $\beta$-damascone, $\beta$-damascenone, and megastigmatrienones, key components of tobacco aroma, was much higher in lamina than in midrib. The results indicate that lamina contains much more carbonyl compounds known to enhance the smoke taste of cigarette, whereas midrib takes nitrogenous and phenolic compounds, which are known to cause a deteriorate effect of smoke such as irritation.

• Mass Spectrometry Letters
• /
• 제3권2호
• /
• pp.29-38
• /
• 2012

A new approach of volatile compounds analysis is proposed using a linear ion trap Orbitrap mass spectrometer coupled with gas chromatography through an atmospheric pressure photoionization interface. In the proposed GC-HRMS/MS approach, direct chemical composition analysis is made for the precursor ions in high resolution MS spectra and the structural identifications were made through the database search of high quality MS/MS spectra. Successful analysis of a complex perfume sample was demonstrated and compared with GC-EI-Q and GC-EI-TOF. The current approach is complementary to conventional GC-EI-MS analysis and can identify low abundance co-eluting compounds. Toluene co-sprayed as a dopant through API probe significantly enhanced ionization of certain compounds and reduced oxidation during the ionization.

• 한국연초학회지
• /
• 제25권2호
• /
• pp.137-143
• /
• 2003

Among the most popular means of mainstream smoke collection for specific analysis are solvent traps. Determination of the carbonyl compounds as their 2,4-dinitrophenylhydrazones(DNPHs) by HPLC offers increased sensitivity and reproducibility in the analysis of mainstream cigarette smoke. In this work, the mainstream smoke of a reference cigarette(lR4F) was collected in four kinds of gas washing bottles and their effects on the analysis of carbonyl compounds were investigated. The results show that the porosity of fritted glass filter in gas washing bottles exerted profound effect on the composition of the carbonyl compounds in mainstream smoke.

• Food Science and Biotechnology
• /
• 제16권1호
• /
• pp.110-115
• /
• 2007

In this study we investigated the volatile compounds that are generated in sesame and contribute to its characteristic flavor. Different reaction systems were used to examine how certain amino acids influenced flavor profiles, and also to evaluate the effects of sugar types on the distribution of those volatile compounds. The volatiles that were generated in each reaction system were selectively isolated and analyzed by gas chromatography and gas chromatography-mass spectrometry, respectively. Among the 20 identified compounds, nitrogen-containing alkylpyrazines were found to be the predominant volatiles. The alkylpyrazine amounts varied across the different model systems, with the total yield being highest in the arginine reaction mixture, followed by the alanine, serine, and lysine mixtures. In general, fructose generated the most extensive amount of volatiles compared to glucose and sucrose. However, the yield of specific flavor compounds varied according to the type of sugar used. Finally, the results clearly showed that a reaction temperature of $135^{\circ}C$ and a reaction time of 20 min generated the highest amount of volatile compounds.

• 한국축산식품학회지
• /
• 제34권5호
• /
• pp.700-708
• /
• 2014

The volatile composition of veal has yet to be reported and is one of the important factors determining meat character and quality. To identify the most important aroma compounds in veal from Holstein bull calves fed one of three diets, samples were subjected to solid-phase microextraction (SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-MS). Most of the important odorants were aldehydes and alcohols. For group A (veal calves fed entirely on milk for 90 d before slaughter), the most abundant compound class was the aldehydes (52.231%), while that was alcohols (26.260%) in group C (veal calves fed starter diet for at least 60 d before slaughter). In both classes the absolute percentages of the volatile compounds in veal were different indicating that the veal diet significantly (p<0.05) affected headspace volatile composition in veal as determined by principal component analysis (PCA). Twenty three volatile compounds showed significance by using a partial least-squared discriminate analysis (PLS-DA) (VIP>1). The establishment of the global volatile signature of veal may be a useful tool to define the beef diet that improves the organoleptic characteristics of the meat and consequently impacts both its taste and economic value.

• Elastomers and Composites
• /
• 제36권1호
• /
• pp.37-43
• /
• 2001

실리카와 카본블랙으로 보강된 SBR 배합물의 가황 특성과 bound rubber 함량 그리고 가황물의 물성에 보강제의 조성비가 미치는 영향을 연구하였다. 고무 배합물의 보강제 총 함량은 80.0 phr 이다. Bound rubber 함량은 실리카 함랑비가 증가할수록 증가하였고 점도 역시 증가하였는데, 특히 실리카 함량이 60.0 phr 이상일 때는 점도의 증가폭이 두드러지게 높아졌다. 가황시간은 실리카 함량이 증가할수록 느려졌고 가황 속도도 느려졌다. 실리카 함량비가 증가할수록 델타 토크가 증가함에도 불구하고 모둘러스는 감소하는 경향을 보였다. $60^{\circ}C$에서의 tan ${\delta}$ 값은 실리카 함량이 증가할수록 감소하였다.

• Journal of Plant Biotechnology
• /
• 제34권4호
• /
• pp.313-322
• /
• 2007

Extract of Japanese red pine needles has been used in Asia pacific regions since long periods believing its valuable properties as tonic and ability of curing diseases of unidentified symptoms. Some selective compounds present in the extract and their effects were analyzed. Carbohydrates and vitamin c were identified using HPLC; terpenoid compounds by GC-MS; anti-bacterial analysis by paper discs, plates count and gastrointestinal motility by whole cell patch clamp. The extract is a mixture of compounds therefore its diverse effect was expected. Self-fermentation in extract proceeds after spontaneous appearance of yeast strains without inoculation. Effects and composition of the extract vary with varying period of self-fermentation. Extract inhibits the growth of bacteria dose dependently exhibiting its antibacterial properties however effectiveness increases with increase in fermentation period. The extract also can modulate gastrointestinal motility in murine small intestine by modulating pace maker currents in ICC mediated through ATP sensitive potassium channel.

• 한국연초학회지
• /
• 제19권1호
• /
• pp.57-63
• /
• 1997

The composition of leaf surface lipid in Flue-cured tobacco and their changes during curing was investigated. The flue-cured variety, Nicotiana tabacum cv. NC 82 was cultivated at Eumsung experiment station in 1996. The samples of riced leaves with different stalk Position(Lugs, Cutter, Leaf and Tips) and different curing stage at half yellowing(24hr), yellowing(48 hr) , color axing(72 hr), midrib drying(96 hr) and cured(120 hr) were collected for analysis of leaf surface lipid. $\alpha$ - and $\beta$ - 4, 8, 13-Duvatriene-1, 3-diol($\alpha$, $\beta$-DVT) were major components in leaf surface lipid extracted with methylene chloride and sugar ester was detected slightly DVT content was increased with ascending stalk position, but increasing trend of total hydrocarbon was not observed. While DVT was decreased throughout curing of tobacco leaves, hydrocarbon content did not show significant change during curing process. Twenty-two duvane compounds were detected by capillary GC in duvane fraction isolated from leaf surface lipid and of which 11 compounds were identified by GC-MS. These compounds were decreased with curing in all stalk position.

• 한국수산과학회지
• /
• 제11권2호
• /
• pp.65-83
• /
• 1978

This study was attempted to evaluate the taste of broiled-dried sea mussel which is a traditional dried Sea food in Korea. The contents of such compounds as free amino acids, nucleotides and their related compounds, TMAO, betaine, and nonvolatile organic acids were analysed. From the results of analysis of nucleotides, the contents of AMP and ADP in broiled-dried Mytilus coruscus and Mytilus edulis appeared higher than other nucleotides and tended to increase slightly after cooking, drying, and storage which might be due to both their stability and the addition of degradation of nucleic acids during cooking. In the free amino acid composition of fresh samples abundant amino were taurine, glycine, serine, glutamic acid, alanine, arginine, threonine, tyrosine, lysine and valine in order. Such amino acids as histidine, leucine, methionine and isoleucine were poor and both proline and phenylalanine were merely trace. The free amino acid composition in the extract of Mytilus corucus and Mytilus edulis after broil-drying was not changed. These amino acids, taurine, glycine, feline, glutamic acid, alanine and arginine were abundant in dried samples as well as in the fresh. The total free amino acid was greatly reduced after cooking and drying ranging from $76.3\%$ to $79.7\%$ loss to that of tile fresh. The content of betaine shelved the same tendency as in total free amino acid while TMA slightly increased relating to TMAO decrease during broil-frying. Such nonvolatile organic acids as succinic, lactic, malic and fumaric acid were abundant in both fresh and broiled-dried samples whereas oxalic and pyruvic acid were poor. It is found that the taste compounds of broiled-dried Mytilus coruscus and Mytilus edulis were composed of amino acids as glycine, serine, alanine, glutamic acid, arginine, and betaine, TMAO, ADP, AMP, and organic acids such as succinic acid, lactic acid, malic acid and fumaric acid. No significant differences in the taste compounds between male and female as well as between Mytilus coruscus and Mytilus edulis was not observed.

• Journal of Ginseng Research
• /
• 제9권1호
• /
• pp.95-103
• /
• 1985

The concentrated red ginseng extract (RG-EXT) was prepared by extracting the ginseng tails with 0-90% ethanol solution at 70-100$^{\circ}C$ and analyzed for amino acids composition and other nitrogeneous fractions. The results showed that nonprotein fraction was more than 90% of the total N-compounds and 17 free amino acids were identified by High Performance Liquid Chromatography. Maximum and minimum N-compounds or total free amino acids were recovered in RG-EXT with 50% and 90% ethanol, respectively. An increase in ethanol concentration resulted a significant change in free amino acid composition while extraction temperature caused a little gradual decrease in water soluble nonprotein and total nitrogen fractions.