• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.270-276
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• 1993

We characterized the character impact compounds of flavors of the fermented Korean soy sauce manufactured with both the traditional and the improved Meju made with different strains. The whole flavor samples were obtained by extracting each volatile flavor phase from both the traditional and the improved soy sauce. To get more detailed information, each whole volatile flavor was further fractionated into the basic, acidic, phenolic and neutral fractions. Each separated peak from the whole and fractionated flavor samples on gas chromatogram was identified by GC/MS and Kovat s retention index, and likewise the aroma of each peak was investigated by a sniffing test with the exercised panel. We were able to identify 15 groups of ingredients with the characteristic soy sauce aroma from the soy sauce made with the traditional Meju and 6 groups from the soy sauce manufactured with the improved Meju made with Aspergillus oryzae. The character impact compounds the two soy sauces were different from each other.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.277-284
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• 1993

We confirmed the character impact compounds of the flavors of the soybean paste manufactured with the traditional and improved Meju, respectively, by using the following methods: gas chromatography (GC), sniffing tests and GC-mass. The soybean paste made with the traditional Meju had 12 compound groups that smelled like the soybean paste flavor, whereas the soybean paste made with the improved Meju had 7 compound groups of soybean paste flavor smell. We were easily able to determine that there is a difference of soybean paste flavor compounds between the soybean pastes made with either the traditional or the improved Mejus because the two soybean paste flavors are very different from each other.

• 한국수산과학회지
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• 제35권2호
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• pp.122-129
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• 2002

민꽃게를 시료로 하여 바람직한 갑각류 향기성분의 전구물질부가 되는 character impact compounds의 검색 및 게 자숙향기의 발현에 대하여 검토하였다. Methanol이 냄새성분의 전구물질 추출에 가장 적합한 것으로 나타났고, 추출횟수는 3회 정도로 완전추출이 가능했으며, 이때 methanol의 농도는 $80\%$일 때가 냄새의 강도가 가장 강한 것으로 나타났다. 시료 게의 냄새성분의 전구물질부를 구명하기 위해 투석 및 이온 교환수지 방법 등을 이용해 냄새성분 전구물질부를 분획하고 관능검사한 결과, 게 자숙취의 전구물질은 수용성이고 투석성의 저분자 성분으로, 산성 및 양성성분의 물질을 주체로 하여 여러 가지 성분이 동시에 가열될 때 발생하는 것이라고 생각되었다 게육 특유의 자숙취를 발현시킬 목적으로, 민꽃게 육의 $80\%$ methanol 추출성분의 조성에 근거한 합성 게육 엑스분의 조제하여 100$^{\circ}C$C에서 30분간 열처리하여 발생하는 냄새를 천연 게육의 자숙취와 비교하여 볼 때, 냄새의 조화성 면에서는 다소 떨어지나 양시료 사이에는 거의 차이가 없었다. 한편, 천연 및 합성 게육의 자숙취를 GC로 분석하여 chromatogram의 pattern을 비교한 결과 저·중비점 물질의 경우 양자가 서로 유사한 것으로 나타났다. 게 자숙취의 발현에는 염기성아미노산을 비롯한 아미노산류의 역할이 컸으며, ribose와 염기성아미노산 간에 일어나는 Maillard 반응에 의해 생성되는 휘발성화합물, 그리고 4급 암모니움염기가 민꽃게 자숙취의 주요 요소가 될 것으로 추정되었다.

• Preventive Nutrition and Food Science
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• 제2권4호
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• pp.360-367
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• 1997

The chemistry background of the Maillard reaction focused on pyrazines and factors affecting the reaction products were reviewed. The Maillard reaction, also called a non-enzymatic browning reaction, is quite complex and generates numerous reaction products. In processed foods, it is generally accepted as a key reaction to produce flavor components. Specially, pyrazines possess an important impact character on the roasted foods with other heterocyclic compounds. The Maillard reaction is initiated by condensation between reducing sugar and amino group, and N-glycosylamines are produced via Schiff base with dehydration of water. After the rearrangement of the N-glycosylamines, they follow transformation into deoxyhexosones which are reactive intermediates. Degradation and fragmentation are facilitated by rearranged compounds. By condensation, pyrazine, one of the final Maillard products, is generated as a relatively stable form to provide specific aromas. During the processes of the reaction, chemical or physical environmental parameters affect the formation of the products.

• Preventive Nutrition and Food Science
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• 제7권4호
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• pp.405-410
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• 2002

Rice wine was prepared with medicinal plants or plant extracts to obtain a value added nutritious alcoholic tonics. Powders of ten medicinal plants (PTM) or aqueous extracts prepared from them (ATM) were added during the initial stage of fermentation. Aroma compounds of rice wine (control) and wines containing PTM or ATM were isolated by liquid-liquid continuous solvent extraction (LLCSE) and analyzed by gas chromatography-olfactometry and aroma extract dilution analysis (AEDA). Desirable aroma compounds: acetaldehyde (sweet, ethereal), benzaldehyde (sweet, fragrant), ethyl acetate (sweet) and ethyl octanoate (sweet, ethanolic) had the highest log$_3$-flavor dilution (FD) factors in ATM. Results of sensory evaluation demonstrated that intensities of undesirable aroma attributes, such as koji and yeasty notes in control, and raw medicinal herb notes in PTM, were lowest in wine with ATM. Wines made with ATM had the most attractive aroma attributes among the three different traditional Korean medicinal wines.

• Journal of Microbiology and Biotechnology
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• 제5권3호
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• pp.143-148
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• 1995

A strain producing soybean paste flavor was isolated from traditional Korean soybean paste. The isolate was identified as Bacillus subtilis PM3. The neutral fraction representing the traditional soybean paste aroma was obtained from the whole volatile components produced by B. subtilis PM3 in cooked soybean. Each separated peak from the neutral fraction of gas chromatogram was identified by gas chromatography-mass spectrometry (GC/MS) and Kovat's retention index, and the aromas of each peak were investigated by a sniffing test with the exercise panel. The twenty-nine components, including six character impact compounds and twelve components of flavors of Korean soybean paste, were confirmed. Some regions of gas chromatogram represented the soybean paste odor. It has been confirmed that traditional Korean soybean paste can be manufactured with the strain B. subtilis PM3.

• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.194-201
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• 1996

To develop a method appropriate for mass production in a factory, we manufactured soy sauce with Bacillus species SSA3-2M1 and fused ST723-F31 at $30^{\circ}C$ with aeration of 1/3 vvm for 40 days. The flavor components extracted from the manufactured soy sauce were fractionated to neutral, acidic, basic and phenolic fraction and identified by GC-mass. Among the 60 kinds of identified flavor components, 16 and 23 components were detected in traditional Korean soy sauce and soybean paste, respectively. There were three peak regions that smelled like soy sauce with the GC sniffing test of flavor components and 2, 6-dimethyl pyrazine, benzaldehyde, 2-methoxy phenol, phenol and benzeneethanol which were identified as character impact compounds of traditional Korean soy sauce and soybean paste were identified in the region that smelled like soy sauce. It is therefore considered possible to achieve mass production of soy sauce with standard quality by Bacillus species SSA3-2M1 and fused ST723-F31 in the factory.

• Carbon letters
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• 제10권2호
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• pp.114-122
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• 2009

Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.