• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.464-473
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• 2018

The objective of the current study was to evaluate the effects of roasting methods on volatile flavor compounds of boricha using solvent-assisted flavor evaporation-gas chromatography (GC)-mass spectrometry and GC-olfactometry. The barley roasting methods tested were air roasting (AR), drum roasting (DR), and air/drum roasting (ADR). Twenty, twenty-one, and eighteen aroma-active compounds were detected in the products of AR, DR, and ADR, respectively. Guaiacol (smoky), 2-acetylpyrazine (almond-like), and furfuryl alcohol (burnt sugar-like) were detected as high intensity aroma-active compounds. Intensities of most aroma-active compounds produced by the DR method were higher. On the other hand, aroma intensities of phenols produced by the AR method, such as guaiacol and 2-methoxy-4-vinylphenol (curry-like), tended to be stronger. Aroma characteristics of phenols are not considered to be desirable for boricha. Although roasting time for DR was longer than that for AR, DR may be an effective barley roasting method for enhancing desirable aroma characteristics of boricha.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.441-446
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• 2006

The objective of this study was to investigate volatile compounds extracted from fresh pork belly during storage time at 4 or $20^{\circ}C$. Approximately thirty-one volatile compounds includingaromatics (6), aldehydes (6), acids (5), alcohols (4), ketones (4), alkanes (4), alkenes (1) and amines (1) in fresh pork belly were identified. Among them, volatile compounds such as 1-butanol, propane, 2-butanol, 3-hydroxy-2-butanone, acetic acid, 3-methyl-1-butanol, 1-pentanol, phenol, 2-pentyl-furan, indole and 2-dodecanone correlated with storage temperature and storage time. Aldehydes including hexanal and hexadecanal at 4t were the predominant volatile compounds, whereas at $20^{\circ}C$ storage, aromatics including phenol and indole, and alcohols including 2-butanol and 1-butanol were the predominant volatile compounds. Contents of 1-butanol, 2-butanol, 3-hydroxy-2-butanone, acetic acid, phenol and indole increased markedly with increased storage time, and 1-butanol, 2-butanol, 3-hydroxy-2-butanone, acetic acid, indole and 2-dodecanone were only detected at $20^{\circ}C$ storage.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.76-76
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• 2020

최근 안전한 먹거리 생산과 치유, 교육 등 다양한 목적으로 도시농업에 참여하는 인구가 늘어남에 따라 도시텃밭의 농약, 비료 사용 등으로 인한 환경오염과 해충 피해, 농산물의 건강성 등 다양한 문제가 제기되고 있다. 따라서 도시텃밭 작물의 생육 증진, 잔류농약 문제 해결 등 농산물 안정성 증가에 기여하고자 식물추출물을 활용한 엇갈이 배추의 생육특성을 조사하였다. 선행연구 결과를 바탕으로 자원식물류 5종(쇠비름, 소리쟁이, 명아주, 박주가리, 환삼덩굴)과 허브류 5종(메리골드, 서던우드, 캐모마일, 애플민트, 로즈마리), 식용작물류 5종(양파, 마늘, 부추, 차즈기, 들깨) 등 추출 대상 식물 15종을 60℃에서 3일간 건조시켜 마쇄하였다. 이후 각 식물체 100g을 35% 에틸알코올 1,000ml에서 7일간 추출하였다. 추출물은 30%로 희석하여 주 2회씩 총 3주간 배추에 엽면살포하였다. 엽면적, 엽수, 지상부 및 지하부 생체중 등 생육특성을 7일 간격으로 조사하였으며 그 결과는 다음과 같다. 엽면적과 엽폭은 환삼덩굴 처리구에서 104.58cm²와 9.80cm로 가장 넓었고, 엽장은 박주가리 처리구에서 25.24cm로 가장 길었으며, 지하부 생체중은 메리골드 처리구에서 6.24g으로 가장 높았다. 엽수는 애플민트와 마늘 처리구에서 6.4개로 가장 많았고, 지상부 생체중과 엽록소는 집단 간 유의한 차이가 나타나지 않았다. 전반적으로 무처리 대비 엽면적 22%, 엽폭 18%의 유의한 생장 차이를 보인 환삼덩굴 추출물과 엽면적 12%, 엽장 17%의 생장 차이를 보인 박주가리 추출물, 엽면적 10%, 엽폭 9%의 생장 차이를 보인 양파 추출물이 엇갈이 배추 생육에 효과적인 것으로 나타났다. 본 연구결과 환삼덩굴, 박주가리, 양파 등 일부 식물추출물이 엇갈이 배추의 생육을 증진시킬 수 있는 것으로 나타나 주말농장 등 도시텃밭에 활용할 수 있을 것으로 사료되었다. 향후 식물추출물의 효과성을 증진시키기 위해 추출 방법과 적정 농도, 보관 시기 등에 대한 연구와 함께 도시텃밭 해충방제 효과를 알아보기 위한 약해검정과 살충효과를 분석할 필요성이 있다.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.49-57
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• 2000

To understand the effects of drying conditions on changes of volatile compounds in fruits of Schizandra chinensis, we analyzed SDE (steam distillation and extraction) extract and Headspace vapor of fresh and dried samples using GC/MS (Gas chromatograph/Mass spectrometer). Contents of essential oils from samples with different drying conditions were 0.58% in fresh ones, 0.60% in freeze dried ones, and 0.30% in hot-air dried ones. In SDE extract, major volatile compounds in fresh samples were terpinen-4-ol(9.01%), ${\gamma}-terpinene(7.02%),\;{\beta}-myrcene(7.55%)$, unidentified sesquiterpenes(28.48%), showing almost the same composition as that in freeze-dried ones, but those in hot-air dried samples at $60^{\circ}C$ were ${\gamma}-terpinene(5.40%),\;{\alpha}-elemene(8.28%)$, unidentified sesquiterpenes(50.38%), indicating the chemical changes during drying procedure. In Headspace vapor, major compounds in fresh samples were ${\beta}-myrcene(22.05%),\;{\gamma}-terpinene(9.47%),\;{\alpha}-pinene(8.91%)$, sabinene(8.48%), which were different from those in SDE extract. In chemical compositions of volatile compounds in dried samples, ${\beta}-myrcene,\;{\alpha}-terpinene$ decreased in the order of freeze-drying > hot-air drying at $60^{\circ}C$ > hot-air drying at $60^{\circ}C$, and ${\alpha}-ylangene,\;{\alpha}-pinene$, camphene increased in the reverse order of the former. We observed the changes of the contents and compositions of essential oils compounds during drying procedure, especially a decrease in monoterpenes and alcohols and an increase in sesquiterpenes with relatively weak volatility.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.880-886
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• 2010

In this study, volatile compounds in liquor distilled from mash produced using koji or nuruk under reduced or atmospheric pressure were analyzed and eventually, the proper starter material and distillation method was selected. Acetaldehyde was detected two or three times more in the liquor distilled under the atmospheric pressure than under the reduced pressure. Furfural was only detected in the liquor distilled under the atmospheric pressure. Esters were detected more in the liquor distilled under the atmospheric pressure than the reduced pressure. Ethyl pelargonate and 2-phenyl ethanol were particularly detected two times more in the liquor distilled under the atmospheric pressure than the reduced pressure. Methanol was detected two times more in the liquor made with nuruk than that with koji. These results suggest that the liquor distilled from the mash produced using koji under the reduced pressure may have the better quality.

• Journal of Life Science
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• v.22 no.6
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• pp.751-759
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• 2012

Microbulbifer sp. was used to acquire the degrading products from Ecklonia cava (DPEC) and the products were investigated to determine the physiological activities. Firstly, 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity and superoxide dismutase (SOD) assay were about 84.1% and 89.6% at 2.5 mg/ml, respectively. In addition, nitrite scavenging ability was shown to be 56.3% at 0.5 mg/ml on pH 1.2. ${\alpha}$-Glucosidase inhibitory activity was increased in a dose-dependent manner and was about 58.7% at 2.5 mg/ml. To determine the influence of DPEC on alcohol metabolism, the generating activity of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were measured. Facilitating rates of ADH and ALDH activities by DPEC were 123.3% and 215.2% at 2.5 mg/ml, respectively. For analyses of anti-wrinkling and whitening effects, its elastase and tyrosinase inhibitory activities were measured and were about 73.1% and 42.2% at 2.5 mg/ml, respectively. These results indicated that DPEC has valuable biological attributes owing to its antioxidant, nitrite scavenging, and alcohol metabolizing activities and ${\alpha}$-glucosidase, elastase, and tyrosinase inhibitory activities.

• Polymer(Korea)
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• v.30 no.3
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• pp.271-278
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• 2006

In order to investigate the structure and dynamics of atatic poly (vinyl alcohol) (PVA)/water system, laser light scattering experiment has been done in the semi-dilute concentration regime at $25^{\circ}C$. The scattering intensity I(q) can be analyzed with the fractal equation of $I(q){\sim}q^{-m}$ instead of Onstein-Zernike type equation. The fractal dimensionality m was found to be constant after reaching the plateau value of $m=2.6{\pm}0.3$ above C=3wt%. The time correlation function of dynamic light scattering has always two different modes such as fast mode and slow one. The cooperative diffusion of fast mode showed concentration independence contrary 4o the reptation theory's concentration dependent exponent of 3/4. The slow mode can be interpreted as the motion of large scale heterogeneities and its strong concentration dependence is apparent with a large negative exponent of -3.0. It is considered that the stereo-regular arrangement with four successive meso units of -OH plays as a key role in forming such heterogeneity.

• Korean journal of food and cookery science
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• v.19 no.1
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• pp.1-10
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• 2003

All optional ingredient, Jasoja(Perillae semen) was adopted to improve Dongchimi in qualify during fermentation. Free sugar, free amino acid, non-volatile organic acid and volatile compounds were determined during fermentation at 10$^{\circ}C$ for 45 days. Free sugar content was slightly higher in 0.5%-Jasoja-treated samples than that of control. The contents of free amino acids in control Dongchimi (without jasoja) increased slowly during fermentation while those in 0.5 %-treated samples began to decrease after reaching their maximum value on the day 11 when Dongchimi became most acceptable. There were 6 non-volatile organic acids, such as lactic, fumaric, succinic, malic, tartaric, and citric acid. Among these, only lactic and succinic acid increased consistently with fermentation while others decreased. Volatile components in Dongchimi were mostly identified as sulfur-containing compounds by gas chromatography. Their numbers and % peak areas in the gas chromatogram decreased slightly with the increase in organic acids and alcohols during fermentation period. On the other hand, Dongchimi prepared with Jasoja maintained its contents of total acids as well as the level of sulfur-containing compounds.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.22-34
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• 1998

The purpose of this study is to develop biosensor for determination of glucose, lactate, and ethanol in foods and food-stuffs simultaneously. The multiple cathode system was prepared with an oxygen electrode having one anode and hexagonal cathode. Glucose oxidase, mutarotase, lactate oxidase, alcohol oxidase and catalase were used for immobilization to determine glucose, lactate, and ethanol. These components including ethanol were simultaneously determined by the immobilized enzymes in the multiple cathode system. The determination of the components by enzyme sensor was based on the maximum slope of oxygen consumption from enzyme reaction of each sensor part. The response time for analysis was 1 min. The optimum condition for glucose, lactate and ethanol sensor was found to be 0.1 M potassium phosphate buffer, pH 7.0 at $40^{\circ}C$. Interferences of various sugars and organic acids were investigated. Less than 10% of error was found in determination of the components except organic acids. This difference was compensated by the modified equation. This system was confirmed by conventional methods. It was concluded that the multiple cathode system of this study is for an effective method to determine sugar, organic acid, ethanol simultaneously in foods.

• Clean Technology
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• v.12 no.4
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• pp.191-197
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• 2006

Polymerization in supercritical carbon dioxide has been getting attention since it is easier to separate the remaining reactants from product polymer and since it is a cleaner process that produces neither wastewater nor air pollutants, compared to the conventional polymerization processes. In this study, poly(vinyl acetate) (PVAc) that is necessary in producing poly(vinyl alcohol) (PVA) with a lot of industrial applications was manufactured in the presence of supercritical carbon dioxide for the second time in the world. A poly(dimethylsiloxane)(PDMS)-derivative surfactant and three initiators were employed in the polymerization of vinyl acetate (VAc) at 338.15 K and 34.5 MPa. Investigation was carried out to find out the effect of the amounts and types of initiators and surfactants as well as the effect of reaction time on the yield and the molecular weight of PVAc. The weight average molecular weight (Mw) of PVAc was in the range of 60,000 ~ 140,000 g/mol, and the number average molecular weight was in the range of 30,000 ~ 70,000 g/mol. The yield of PVAc was spread over 10 ~ 80%, based on the amount of VAc monomer.