• Food Science and Biotechnology
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• 제17권1호
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• pp.90-94
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• 2008

Dynamic rheological properties of honey samples with 3 different moisture contents (17.2, 19.0, and 21.0%) were evaluated at various low temperatures (-15, -10, -5, and $0^{\circ}C$) using a controlled stress rheometer. The honey samples displayed a liquid-like behavior, with loss modulus (G") predominating over storage modulus (G') (G">>G'), showing the high dependence on frequency ($\omega$). The magnitudes of G' and G" decreased with an increase in temperature and water content while a predominant increase of G' was noticed at $-15^{\circ}C$. The time-temperature superposition (TTS) principle was applied to bring G" values for honeys at various temperatures together into a master curve. The G" over the temperature range of -15 to $0^{\circ}C$ obeyed the Arrhenius relationship with a high determination coefficient ($R^2=0.98-0.99$). Activation energy value (Ea=112.4 kJ/mol) of honey with a moisture content of 17.2% was higher than those (Ea=98.8-101.1 kJ/mol) of other honey samples with higher moisture contents.

• 한국약용작물학회지
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• 제19권4호
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• pp.271-275
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• 2011

In this study, ginseng flower water extracts were analyzed to set up the ginsenoside content and quality optimization condition. The highest total ginsenoside content among the ginseng flower water extracts was 67.44mg/g which was extracted at $85^{\circ}C$ for 3 hours. In addition, the ginsenoside content decreased according to the increased extraction temperature and time. The highest total content of $Rb_2$ and Re was 37.42mg/g at $75^{\circ}C$ for 6 hours. Total content of $Rb_2$ and Re decreased according to the increased extraction temperature and time. The highest prosapogenin ($Rg_2$ + $Rg_3$ + $Rh_1$) content among the total of ginseng flower water extracts was 18.58mg/g which was extracted at $95^{\circ}C$ for 12 hours. The sweetness, absorbance were increased according to the increased extraction temperature and time. But pH was decreased according to the increased extraction time.

• 대한본초학회지
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• 제27권6호
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• pp.139-145
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• 2012

Objectives : This study aimed to investigate value differences among Gastrodiae Rhizoma samples(GM, GC, G1, G2 and G3) in various characteristics as well as to provide basic guideline for various processes such as steaming and drying of Gastrodiae Rhizoma. Methods : Gastrodiae Rhizoma were steamed and dried at different temperature and times. They were divided into samples (GM; cultivated, steamed and dried in Muju, GC; cultivated and dried in China, G1; steamed and dried at $55^{\circ}C$ for 60 hours, G2; steamed and dried at $55^{\circ}C$ for 120 hours, G3; steamed and dried at $70^{\circ}C$ for 120 hours) for experiment. They were extracted using water, freeze dried and powdered to analyze gastrodin content, antioxidant activity and sensory evaluation. Results : Proximate composition and the amount of free sugars of Gastrodiae Rhizoma had a little bit differences. Phenolic and flavonoid content of samples were increased by increasing drying temperature and times. Gastrodin content had different values by drying method and G3 was the highest in comparison with others. Increasing drying times led to a increasing in radical and nitrate scavenging activity in samples. Regarding to sensory evaluation, G3 was selected as the best sample according to its highest hedonic score mean (6.11/7) among all samples for appearance, color, flavor, overall acceptability. Conclusions : The results indicated that G3 sample was effective in views of antioxidant activity, gastrodin content and sensory characteristics. Moreover, Gastrodiae Rhizoma cultivated in Korea were investigated with higher antioxidant activity, gastrodin content and sensory characteristics than those cultivated in China.

• 한국세라믹학회지
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• 제21권2호
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• pp.156-164
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• 1984

The characteristic of pyrolytic carbon deposited in a fluidized bed as measured by density apparent crystallite size and viewed metallographically under polarized light can be easily controlled by adjusting the deposition parameters such as deposition temperature and propane flow rate or silicon content. The density of isotopic pyrolytic carbons deposited from propane between 120$0^{\circ}C$ and 140$0^{\circ}C$ increases with increasing propane flow rate and decreasing deposition temperature from 1, 73g/cc to 2.08g/cc. The apparent crystallite size Lc parameter appears to depend only on deposition temperature being entirely independent of the propane flow rate. The carbon matrix density of the silicon-alloyed carbonds deposited from propane and methyltrichlorosil-ane from 2.05g/cc for a silicon content around 9wt% to 2.67g/cc for a silicon content of 36.7wt% The Lc parameter of the deposition temperature being entirely independent of the silicon content.

• 한국연초학회지
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• 제29권2호
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• pp.59-65
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• 2007

The study was carried out to investigate water activity, physicochemical properties and color degree of burley tobacco stored in shelf with different moisture content for 56 days. The study was consist of two experimental designs, that is, moisture content in burley tobacco was kept to 13 to 15 %, 17 to 19 %, and 21 to 23 % under ambient temperature of $20^{\circ}C$ with relative humidity of 24 %, and another group of in burley tobacco was only kept in ambient temperature of $3^{\circ}C$ with relative humidity of 50 % for 56 days with same water content of former treatment. Normal leaves were kept for 56 days under 21 to 23% of moisture content with increased water activity and TSNA(tobacco-specific nitrosamine content. It was considered that favorable leaves conditions are due to favorable microbial growth resulting in increased TSNA content. The total nitrogen content has not changed in two experimental groups for 56 days, otherwise the nitrate form nitrogen and total alkaloid contents were only increased by 21 to 23 % of water content. Degree of pH change was slightly decreased in both storage and water treatment. It was more decreased in 21 to 23% of moisture content than that of other moisture content. In stored leaf tobacco, higher moisture content caused lower brightness, yellow degree, and carbonization quotient.

• 한국작물학회지
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• 제50권spc1호
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• pp.1-3
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• 2005

흑자색미의 C3C함량을 신속하게 분석하는데, FT-NIR을 이용한 C3G 함량 분석의 예측값과 HPLC 측정값의 정확도를 비교하였다. 1. FT-NIR을 이용한 C3G 함량 분석에서 사용된 시료는 별도의 전처리 과정없이 현미 상태 측정하여 HPLC 분석방법에 비하여 많은 시간과 비용을 아낄 수 있다. 2. 흑진주벼와 수원425호를 교배한 $F_{10}$ 385 계통을 사용하여 얻은 FT-NIR 검량식은 매우 높은 정상관을 보였다($R^2=0.943$, SEE=0.116). 이 검량식을 검증한 결과도 매우 높은 정상관을 보이고 실험오차도 매우 적어($R^2=0.928$, SEP=0.122) 측정정확도가 높게 평가되었다. 3. 본 연구의 결과, FT-NIR을 이용하여 비파괴적으로 신속하게 흑자색미의 C3G함량을 측정할 수 있게 되었다. 그리고 본 연구의 결과를 C3G함량이 높은 벼를 개발하는데 많은 양의 시료를 빠르게 분석할 수 있는 방법으로 이용할 수 있을 것이다.

• 기술사
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• 제18권4호
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• pp.12-22
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• 1985

This investigation was attempted to determine changes in chlorophyll. Pheophytin content PH and titratable acidity during young redish Kim chi fermentation. Young redishes divied in to leaf and vein and fermented in dark room for 35 days at 10$^{\circ}C$ after pickling each group. Samples were collected at 5 days interval for the chemical analysis. The following results were obtained. 1. Chlorophyll content in young redish was decreased by decreasing PH during fermentation periods. Chlorophyll content decreased from 11.60mg/g to 7.62mg/g in leaf, from 0.48mg/g to 0.33mg/g in vein respectively during 35 days fermentation periods. In contrast to chlorophyll. pheophytin content increased as chlorophyll content decreased during the period. The ratio of chlorophyll a and b content in young redish about 3 : 1 in leaf and vein and decreased nearly the same ratio during fermentation periods. In case of pheophytin a and b it was increased without any relation with the ratio chlorophyll a and b. In generally, the optimum PH for eating was known 4.3 to 5.0. Young redish Kim chi was reached the optimun PH at 15 to 25 days of fermentation at 10$^{\circ}C$. At this periods. Chlorophyll content varied from 11.32mg/g to 9.30mg/g for leaf and from 0.43mg/g to 3.37mg/g for vein, respectively. 2. Titratable acidity(as lactic acid) was increased to 0.54% in leaf at 20 days fermentation period during Kim chi fermentation. and nearly unchanged until 30days. At the end of fermentation period the titratable acidity was about 0.30％. Titratable acidity was increased as decreasing pH. and the correlation coefficients was -0.92 in leaf and -0.77 in Vien. 3. Correlation between titratable acidity and chlorophll, pheophytin content was not significant statistically.

• 한국자원식물학회지
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• 제20권5호
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• pp.461-465
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• 2007

블랙 라스베리 과실의 성숙정도에 따른 항산화 활성과 이와 관련된 인자인 총페놀성 함량 및 비타민 C 함량의 변화를 측정하였다. 이러한 결과들로부터 과실의 성숙 단계에 따른 활성 및 성분변화 그리고 이들 간의 상관관계를 구명하였다. 블랙 라스베리 과실의 항산화활성측정 결과, 자유 라디칼 소거능 및 환원력 모두 과실이 성숙함에 따라 감소하였다. 또한 항산화 활성과 밀접한 관계가 있는 총페놀 함량 및 비타민 함량 역시 과실이 성숙함에 따라 감소하였다. 자유 라디칼 소거능은 과실 결실 5일 후에서 125ppm 농도에서 61.67%로 최대치를 나타내었으며 환원력은 과실 결실 10일 후가 0.71로 최대였다. 총페놀 함량과 비타민 C함량의 최대치는 각각 220.73ug/g과 540.45ug/g였다. 여러 인자들에 의한 상관관계 분석 결과 자유 라디칼 소거 활성과 환원력 그리고 환원력과 총페놀 함량과의 상관관계는 각각 r=0.9861와 r=0.9889로 고도의 상관관계를 나타내었다. 이상의 결과를 종합하여 보면, 블랙 라스베리를 수확함에 있어 완숙과보다는 미숙과가 약리적인 측면에서는 유용한 성숙단계라 할 수 있지만 크기나 무게 그리고 맛이나 과색에서는 완숙단계가 식용으로는 적합하고 항산화 활성 등에서는 낮으나 이용 가능한 약리 효과를 가지고 있다고 할 수 있다.

• 한국해양바이오학회지
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• 제10권2호
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• pp.73-82
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• 2018

Chlorella are source of valuable compounds as lipids, proteins, carbohydrates, bioactive compounds. To continuous obtain the high-value materials of Chlorella protothecoides, we performed continuous cultivation after applying milking techniques to C. protothecoides grown with culture for 7 days in optical panel bioreactor (OPBR) system. Fatty acid and lutein in extracts from pre- and post-milking of C. protothecoides were analyzed using gas chromatography and high performance liquid chromatography, respectively. C. protothecoides were rich in unsaturated fatty acids with a high content of oleic acid(C18:1), which is suitable as a biofuel feedstock. The fatty acid content in pre- and post-milking of C. protothecoides was decreased from 126.424mg/g d.w. to 119.341mg/g d.w, and the lutein content decreased from 0.258mg/g d.w. to 0.178mg/g d.w. The results of this study demonstrate the feasibility of milking C. protothecoides for production of lipids for biofuels production. It was confirmed that microalgae can continuously obtain lutein present in a trace amount through a continuous culture from milking.

• 한국식생활문화학회지
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• 제23권1호
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• pp.121-129
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• 2008

To produce buckwheat sprouts, buckwheats were germinated at $23{\pm}2^{\circ}C$ up to 8 days in total darkness. In proximate analysis, moisture content increased from 13.87% of buckwheat groats to 93.75% of buckwheat sprouts on the 8th day of germination. On dry weight basis, lipid and ash contents increased like as protein content increased from 13.45% to 21.82% while carbohydrate content decreased due to enzyme hydrolysis. Amino acids were rich in glutamic acid, aspartic acids, and lysine, and also the ratio of the essential amino acids to total amino acids increased from 26.84% to 36.84%. Vitamin C did not exist in buckwheat groats but its content has continued to increase as far as 99.56 mg/100 g buckwheat sprouts. Rutin continued to increase by HPLC analysis from 4.71 mg/100 g buckwheat groats to 1,524 mg/100 g buckwheat sprouts. In analysis of organic acids, oxalic, maleic, and citric acids were commonly found in buckwheat sprouts. Fagopyrin was found almost none in buckwheat sprouts. In conclusion, the conversion of buckwheat seeds into sprouts through germination in darkness results in physically different final product with nutritional changes such as higher content of rutin, generation of vitamin C, abundance of the essential amino acids, and the existence of fagopyrin on very little.