• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.457-462
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• 2015

Hemicellulosic hydrolysates contain not only sugars but also several kinds of ethanol fermentation inhibitory substances such as carboxylic acids, furans and phenolic compounds. In this work, emulsion liquid membrane (ELM) was chosen as a separation technology to remove the inhibitors. A basic simulated hemicellulosic hydrolysate was composed of xylose as sugar, dilute sulfuric acid solution as solvent, and acetic acid as carboxylic acid, and furfural as furan derivative or p-hydroxybenzoic acid(HBA) as phenolic compound was added to the hydrolysate when necessary. Acetic acid and HBA as weak acid could be selectively removed from the hydrolysates in all the ELM systems considered here, but furfural as aldehyde was quite hard to remove. Also, when HBA was added to the basic simulated hemicellulosic hydrolysate, both of acetic acid and HBA in the feed phase could be selectively removed up to 99% in an ELM system with tributyl phosphate as extractant.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.3943-3949
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• 2012

A series of aromatic hydrazides 3a-j were prepared by refluxing esters 2a-j with hydrazine hydrate in methanol, which were prepared by the esterification of 1a-j. Acetohydrazides 3a-j upon treatment with carbon disulfide and methanolic potassium hydroxide yielded potassium dithiocarbazate salts 4a-j, which on refluxing with hydrazine hydrate yielded substituted 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-j. The target compounds 6a-j were synthesized by condensing furan-3-carboxylic acid in the presence of polyphosphoric acid under reflux. The structures of newly synthesized compounds were characterized by IR, $^1H$ NMR, $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their urease, acetylcholine esterase inhibition, antioxidant and alkaline phosphatase inhibition activity. Almost all of the compounds 6a-j showed good to excellent activities against urease and acetylcholine esterase more than the reference drugs. Compounds 6f and 6g were more potent scavenger of free radicals than the reference n-propyl gallate. Compound 6b and 6h showed excellent activities of alkaline phosphatase as compare to the reference $KH_2PO_4$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1033-1037
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• 2001

Garlic oleoresins were made by extracting with four solvents of methanol, methyl acetate hexane and acetone from chopped garlic, respectively, and the volatile compounds of each extract were separated by gas chromatography installed with polar (supelcowax-10$^{TM}$) and nonpolar (HP-5) capillary columns, respectively, and identified by matching mass data of mass selective detector and Kovat\`s retention index with references. The numbers of the volatile compounds identified the garlic oleoresin by polar and nonpolar columns from in garlic oleoresins were 41 and 32, respectively. In polar column, 13 pyrans, 11 sulfur-containing compounds 6 furans 2 alcohols and 2 heterocyclic compounds were identified. In nonpolar column, 11 sulfur-containing compounds 5 acids 3 furans and eugenol were identified. The major sulfur-containing compounds identified from the oleoresins were 3, 3'-thiobis-1-propene, methyl 2-propenyl disulfide, dimethyl trisulfide, di-2-prnpenyl-trisulfide, 2-thiophenecarboxylic acid. The amount of these sulfur-containing compounds isolated from the oleresins were more abundant in polar column than in nonpolar column. The most efficient solvent for extracting volatile compounds of garlic was methanol but the most useful solvent for extracting sulfur-containing compounds was methyl acetate of less polarity.y.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.5-20
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• 1991

For the quality enhancement of harvested-year leaf tobacco to the quality of 2-year naturally aged leaf tobacco, cellulose and nicotine degradative bacteria were isolated and identified. Effects of artificial fermentation treated cellulase and nicotine degradative bacteria on the quality of leaf tobacco were investigated from the chemical and sensory points of view. 1, Changes in chemical composition of leaf tobacco resulted from the addition of cellulase extracted from Cellulomonas sp. [3ml(${\mu}{\textrm}{m}$ D-glucose/ml. mil-1) of enzymes solution 11009 of leaf tobacco] and nicotine degradative bacteria, Pseudomonas sp. 2ml(IX109 cells$\div$ 100g of leaf tobacco), and subsequently fermented at 40${\mu}{\textrm}{m}$$^{\circ}C$, 65% R. H. for 40 days are as follows : 1) Content of crude fiber decreased 12% It took 9 min, 53 sec. to reach full combustion in control group but took only 7 min. 47 sec. in the treated group, taking almost equal time to 2-year naturally aged leaf tobacco(7 min. 35sec.). 2) Light intensity of control group was 60.96% with bright lemon color but that of treated leaf tobacco accounted for 47.69 with orange to dark brown color series, which was almost equal to the value, 45.69, of 2-year naturally aged leaf tobacco. 3) Linoleic acid, serving mild taste among organic acids, amounted to 1.llmg/g in control group but increased to 1.35m9/9 in the treated leaf tobacco, identical to the content(1.35mg/g) of 2-year naturally aged leaf tobacco. 4) Content of solanone, on of the typical leaf tobacco flavor compounds, accounted for 2.95% in control group but increased to 2.87% in treated group. 5) Methyl furan, useful flavor compound in smoke composition, accounted for 17.6$\mu\textrm{g}$/cig. in control group but increased to 25.9$\mu\textrm{g}$/cig. in treated group. However, acroleine decreased from 69.3$\mu\textrm{g}$/cig. in control group to 58.6$\mu\textrm{g}$/cig. in treated group 2. In sonsory test, mild taste evaluation of control group scored 5.47 and treated group 7.93 which was evaluted almost equal to the value(8.00) of 2-year naturally aged leaf tobacco. Aroma evaluation of control group scored 5.60, treated group 8.20, and 2-year naturally aged leaf tobacco 8.33. In addition, total harmony taste of control group showed 5.67, treated group 8.07 (p<0.01), and 2-year naturally aged leaf tobacco 8.00. From these results, it can be said that quality of treated leaf tobacco is not inferior to that 2-year naturally aged leaf tobacco.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.255-261
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• 2013

This study investigated changes in the physicochemical characteristics and coffee flavors of coffee beans under different roasting conditions. Four different kinds of roasted coffees were analyzed using a headspace gas chromatographic technique. The moisture content and total acidity of roasted coffee decreased whereas the pH and weight loss (%) increased, as coffee beans were roasted at higher temperatures. The Hunter's color values of the roasted coffee (indicating L (lightness) and b (yellowness)) decreased as the roasting temperature of the coffee beans increased, but a (redness) value only increased with light roasting. We also noted that the color of the Arabica coffee was darker than that of the Robusta coffee. The aroma compounds, acetaldehyde, acetone, 2-methylfuran, 2-methylbutanol, 2-methylpyrazine, furfural, 2-propanone, furfuryl alcohol, 2,5-dimethylpyrazine and furfuryl acetate were mainly analyzed. A sensory evaluation of all light-roasted coffees had flavor and sourness and those of all medium-roasted coffees had heaviness and finishness.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.286-292
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• 2007

Free amino acids and volatile compounds of fresh garlic and its liqueur were investigated to search elution profile of those components as basic data for development of garlic liqueur. The garlic was soaked in 20% alcohol solution and then sampled every week for 5 weeks. The major free amino acids were L-aspartic acid, L-glutamic acid, L-arginine, L-alanine, L-proline, L-asparagine and L-serine. Neutral amino acids such as L-threonine, L-proline, L-valine and L-leucine, and aromatic amino acids such as tyrosine and phenylalanine were eluted over 80% of those content in fresh garlic after 3 weeks of soaking, but acidic, basic and sulfur containing amino acids were below 80% even after 5 weeks. Sulfide compounds such as diallyl trisulfide, diallyl disulfide, methyl allyl disulfide, 2-vinyl-4H-1,3-dithi in, 3-vinyl-3,4-dihydro-1,2-dithiin, 3,5-diethyl-1,24-trithiolane, isobutyl isothiocyanate and diallyl sulfide were identified as major volatile compounds of fresh garlic by using GC/MS. Among volatile compounds of fresh garlic, allyl alcohol, diallyl disulfide, 3,5-diethyl-1,2,4-trithiolane, diallyl trisulfide and 3,4-dimethoxy furan were eluted to liqueur, but those compounds except 3,5-diethyl-1,2,4-trithiolane were lowered in liqueur during soaking. Furfural, 5-methylfurfural, 5-hydroxymethylfurfural, dimethyl pyrazine, furfuryl alcohol, 3-hydroxy-2-bytanone and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyr-an-4-one were generated newly and their content increased in liqueur during soaking.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.548-552
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• 2005

Volatile fragrance components in 5 kinds of Korean native Lilium were investigated and compared. The volatile components were extracted by SDE (simultaneous steam distillation and extraction) and identified by CC and GC-MS. As a result of the analysis of volatile aromatic ingredient of L. leichtlinii var. tigrinum Nickels., L. concolor var. parthneion Bak., L. tsingtauense Gilg., L. hansonii Leichtl., and L. amabile Palibin., using frozen materials, 60 kinds of volatile compound were identified, which were 28 aldehydes, 9 ketones, 8 alcohols, 5 esters, 5 acids, 3 furans and 2 others. The GC patterns of the aroma components of all samples resembled but the peak areas were different according to species, though all of them are Korean native Liliums.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.4
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• pp.242-250
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• 2016

Although rice has been cultivated as a major food crop for approximately 5,000 years, the interest of customers in 'scented rice' is a recent trend in the Korean market. As a part of developing a germinated scented rice variety, the newly bred scented rice variety 'Cheonjihyang-1 se' was germinated for 24 h, and changes in profiles of flavor-related volatiles, lipophilic phytonutrients, and fatty acids were investigated. The profiling of volatile compounds by using a headspace-gas chromatography-mass spectrometry (HS-GC-MS) revealed a total of 56 odor-active flavoring compounds; 52 at the pre-germination stage, 51 at the post-germination stage, and 47 common at both stages. The major flavoring compounds were nonanol and benzene, which constituted 11.5% and 6.6%, respectively, of the total peak area in pre-germinated rice, and 19.4% and 6.5%, respectively, in post-germinated rice. Germination induced an increase in 13 flavoring compounds, including 3,3,5-trimethylheptane and 1-pentadecene, which increased by 763 and 513%, respectively by germination. However, we observed a germination-induced decrease in most of the other flavoring compounds. Especially, the most important scented rice-specific popcorn-flavoring compound, 2-acetyl-1-pyrroline, showed 89% decrease due to germination. Furthermore, the germination of scented rice induced a decrease in the content of various phytonutrients. For example, the total contents of phytosterols, squalene, and tocols decreased from 207.97, 31.74, and $25.32{\mu}g\;g^{-1}$ at pre-germination stage down to 136.66, 25.12, and $17.76{\mu}g\;g^{-1}$, respectively at post-germination stage. The fatty acid compositions were also affected by germination. The composition of three major fatty acids, linoleic, oleic, and palmitic acids, increased from 36.6, 34.2, and 24.4%, respectively, at the pre-germination stage to 37.9, 36.9, and 20.7%, respectively, at the post-germination stage. All these results suggested significant changes in the flavor-related compounds and phytonutrients of the scented rice variety 'Cheonjihyang-1 se' during the process of germination, and subsequently the need for developing a more precise process of germination to enhance the flavor and nutritional quality of the germinated scented rice products.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.283-291
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• 2017

Rice that the half of population in the world eats as a staple food is mostly produced and consumed in Asia. However, its consumption is nowadays decreasing mainly due to diet diversity. Accordingly, some attempts are in demand to enhance the utilization of rice. In this study, profiling of volatile and non-volatile flavor components in rice pastes obtained by ${\alpha}$-amylase was performed and compared according to nine different rice cultivars domestically cultivated in Korea using gas chromatography-mass spectrometry combined by solid phase microextraction and gas chromatography-time of flight-mass spectrometry after a derivatization, respectively. In total, 46 volatile compounds identified included 6 alcohols, 6 aldehydes, 4 esters, 4 furan derivatives, 4 ketones, 1 acid, 1 sulfur-containing compound, 7 hydrocarbons, 5 aromatics and 8 terpenes. The non-volatile flavor components found were composed of 12 amino acids, 6 sugars and 4 sugar alcohols. In principal component analysis, rice paste samples could be discriminated according to cultivars on the score plots of volatile and non-volatile flavor compounds. In particular, some volatile compounds such as pentanal and 4,7-dimethylundecane could contribute to distinguish Senong 17 white and Senong 17 brown, whereas ethanol, 6-methylhep-5-en-2-one, and tridecane could be highly related to the discrimination of Iipum from other cultivars. Among non-volatile compounds, some amino acids such as glycine, serine and ${\gamma}$-aminobutyric acid and some sugars such as sucrose and fructose were mainly responsible for the discrimination of Danmi from the other cultivars. On the other hand, galactose, arabitol and mannose were more closely related to Senong 17 white than Senong 17 brown.