• Journal of Ginseng Research
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• 제14권1호
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• pp.21-26
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• 1990

The chemical composition and stabilities of the purified ginseng invertase were investigated. The purified enzyme was found to be a glycoprotein composed of 80.2% protein and 19.7% total sugar. The protein component of the enzyme was composed of acidic amino acid (9.3%), basic amino acid (48.9%), nonpolar amino acid (21.4%), polar amino acid (20.4%) and 6.1% S-containing amino acid. It showed especially high contents of histidine and serine. The enzyme was inactivated almost completely by the treatment with some proteases (papain, pepsin. trypsin, pancreatin and microbial alkaline pretense) and protein denatllrants (8M urea and 6M guanidine-HC1), bolt not with glyrosidase (${\alpha}$-amylase, ${\beta}$-amylase. glcoamylese and cellullase). btonosaccharides sllch as glilrose, fructose, galactose and mannose did not exert any influence on the enzyme activity. The activity of the enzyme was inhibited by Ag+, Mn2+, Hg2+, Zn2+ and Al3+, whereas Ca2+, Mg2+, Ba2+ and Fe3+ gave rather activating effects on the enzyme activity. The enzyme was relatively stable in the VH range of VH 6 and 8, and at the temperatures below 35$^{\circ}C$.

• Preventive Nutrition and Food Science
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• 제9권3호
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• pp.199-205
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• 2004

The effect of chitosan on enzymatic activities and on bioactive compounds was characterized during germination at $25^{\circ}C$ for 7 days to search for a method to produce a germinated black rice. The germination rate was reduced by the addition of lactate and chitosan. The rotting rate was greatly decreased by chitosan, suggesting that the addition of chitosan into a germination solution might be an effective method for controlling fungal contamination during the germination of cereals. The addition of 100 and 200 ppm chitosan increased $\alpha$-amylase activity after 7 days by up to 152 % and 197 %, respectively. The activities of $\beta$-amylase and $\beta$-glucosidase were lower with 200 ppm chitosan than in distilled water and 100 ppm lactate. The amount of total soluble phenolics and total flavonoids decreased rapidly for four days and thereafter remained constant until the seventh day. The antioxidant activity of germinated black rice, in terms of hydrogen-donating activity, increased slowly and did not correspond to the changes of total soluble phenolics and total flavonoids. The amount of phytic acid was reduced by the addition of 200 ppm chitosan compared to distilled water, indicating that chitosan could be used as an elicitor for the increase of phytase activity during the germination of black rice.

• 한국조리학회지
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• 제6권3호
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• pp.357-371
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• 2000

Changes of Microflora, enzyme activity, and contents of several taste compounds in traditional Kanjang(Korean Soy Sauce) with the variation of fermentation jars and Meju(fermented soybean brick)concentration were studied. Substitution possibilities of clay jar with glass jar and improvement possibilities of taste and nutritional value with increased Meju concentration were examined. (1) Aerobic bacteria and lactic acid bacteria were enumerated during fermentation and ripening period. But yeast and molds were hardly isolated. The number of viable cells showed small changes during fermentation and ripening period. (2) Isolated Aerobic bacteria were identified as Bacillus subtilis, Bacillus lichenformis, and lactic acid bacteria were identified as Lactlbacillus lactis lactis and lactobacillus brevis. (3) The activities of $\alpha$-amylase and $\beta$-amylase increased during fermentation period, but did not show any trend by fermentation jars or Meju concentrations. Protense activity showed small difference among four samples, and increased during the fermentation period.

• 한국식생활문화학회지
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• 제9권2호
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• pp.143-148
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• 1994

'Nochi' is one of Korean traditional panfried rice cakes made from glutinous rice or millet and malt. The optimum conditions for the preparation of 'Nochi' were investigated. The ${\alpha}-amylase$ activity of malt was 62.5 units/g dry malt and ${\beta}-amylase$ 1.43 units/g dry malt. Reducing sugar content of 'Nochi' increased with the content of malt and saccharifying time. Both the hardness and cohesiveness of 'Nochi', measured by rheometer, were decreased with increasing the content of malt, while adhesiveness and hardness increased with saccharifying time, but cohesiveness decreased. The optimum conditions for the preparation of 'Nochi' were 8.0%(w/w) of malt and 1 hour 45 minutes of saccharifying time.

• 한국식품조리과학회지
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• 제7권4호
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• pp.9-13
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• 1991

Nochi is a kind of Korean traditional food made from glutinous rice or millet. This study attempted to examine the effects o( the various factors and to clarify the factors which affect the overall eating quality of Noch. The results were summarized as follows. 1. Starch content of waxy rice was 72.4% and IBC was 0.017%. 2. $\alpha$-amylase and $\beta$-amylase activity of malt were 40.13 and 8.94 units respectively. 3. Waxy rice soaked for 3 hours was ground to flour then sifted 20 mesh sieve. The mixture of waxy rice and malt was steamed for 20 minutes. 4. In sensory evaluation on varying the amount of malt and incubation time, the most favorite tendancy of the overall eating quality was at the level of 8hours incubation made by 5% addition of malt. 5. Total sugar contents, reducing sugar contents and the intensities of iodine stain at the incubation temperature of $60^{\circ}C$ were significantly different from those at $50^{\circ}C$.

• 한국미생물·생명공학회지
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• 제28권1호
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• pp.59-61
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• 2000

The various extracellular enzymes produced by lactic acid bacteria isolated from kimchi were assayed to improve the shelf-life of kimchi. Peroxidase was not detected in all tested lactic acid bacteria and small amount of ascorbic acid oxidase was detected in Pediococcus pentosaceus and Lactobacillus brevis. In case of $\alpha$-amylase, 27.8 and 20.9 unit/mg were shown in Pediococcus acidilactici and Pediococcus pentosaceus, respectively but $\beta$-amylase and protease activities were very low. The enzyme related to textural property of kimchi, pectinesterase showed low activity but polygalacturonase activity was 0.28 unit/mg in Lactobacillus homohiochii and 0.27 unit/mg in Lactobacillus plantarum.

• 한국식품과학회지
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• 제27권1호
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• pp.56-62
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• 1995

This study was designed to investigate the changes in microflora and enzyme activities of traditional kochujang meju during fermentation for 60 days. The pH of meju decreased continously up to 40 days of aging and then increased slightly thereafter, while the change in titratable acidity showed the opposite trend to that of pH. The viable cell count of aerobic bacteria increared gradually for up to 40 days of fermentation and then decreased slightly thereafter, while that of molds and yeasts showed a rapid increase up to 40 days of fermentation and then leveled off. ${\alpha}-amylase$ activity increased slightly for up to 40 days of meju fermentation and then stabilized. On the other hand, ${\beta}-amylase$ and glucoamylase activities did not show a significant change for up to 20 days of fermentation and then increased rapidly at 40th day of fermentation. Acidic, neutral and alkaline protease activities increased sharply up to 40 days of aging and then decreased significently at 60th day of fermentation. These results suggest that meju fermented for 40 days had the highest quality in terms of the number of microflora and enzyme activity.

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1725-1731
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• 2002

The distribution and activities of hydrolytic enzymes (cellulolyti, hemicellulolytic,pectinolytic and others) in the rumen compartments of Hereford bulls fed 100% alfalfa hay based diets were evaluated. The alfalfa proportion in the diet was gradually increased for two weeks. Whole rumen contents were processed into four fractions: Rumen contents including both the liquid and solid fractions were homogenized and centrifuged, and the supernatant was assayed for enzymes located in whole rumen contents (WRE); rumen contents were centrifuged and the supernatant was assayed for enzymes located in rumen fluids (RFE); feed particles in rumen contents were separated manually, washed with buffer, resuspended in an equal volume of buffer, homogenized and centrifuged and supernatant was assayed for enzymes associated with feed particles (FAE); and rumen microbial cell fraction was separated by centrifugation, suspended in an equal volume of buffer, sonicated and centrifuged, and the supernatant was assayed for enzymes bound with microbial cells (CBE). It was found that polysaccharide-degrading proteins such as $\beta$-1,4-D-endoglucanase, $\beta$-1,4-D-exoglucanase, xylanase and pectinase enzymes were located mainly with the cell bound (CBE) fraction. However, $\beta$-D-glucosidase, $\beta$-D-fucosidase, acetylesterase, and $\alpha$-L-arabinofuranosidase were located in the rumen fluids (RFE) fraction. Protease activity distributions were 37.7, 22.1 and 40.2%, and amylase activity distributions were 51.6, 18.2 and 30.2% for the RFE, FAE and CBE fractions, respectively. These results indicated that protease is located mainly in rumen fluid and with microbial cells, whereas amylase was located mainly in the rumen fluid.

• 한국미생물·생명공학회지
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• 제11권1호
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• pp.67-74
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• 1983

Aspergillus oryzae 6균주(A, B, C, D, E, F 등 6개구)를 이용한 콩된장및 개량된장의 색상개량에 관한 연구결과를 요약하면 다음과 같다. 제국중 protease 및 $\alpha$, $\beta$-amylase 활성은 콩된장구보다 개량된장구에서 더 높았고 전반적으로 48시간까지는 그 활성이 급격히 그리고 12시간까지는 서서히 증대되었으며, A 및 C 균주구의 활성이 높았다. 그리고 숙성중 일반성분, 단백질 화합물, pH 등의 변화에 있어서 콩된장 및 개량된장 모두 균주에 따른 차이는 없었다. 균주에 따른 숙성중의 색상변화 즉 갈변현상은 균주의 차이에 따라 그 차가 심하였고 B 및 균주구에서 완만하여 색상이 우수하였으며 개량된장보다 콩된장에서 더 갈변이 심하였다. 그리고 숙성된장의 저장중에서도 같은 경향을 보였으며 내부보다는 표면에서 더욱 심하였다. 그리고 이와같은 갈변화 현상은 효소학적 반응이 주요인으로 고려되었다. 전반적으로 Aspergillus oryzae 2157(C)균주에 의한 된장 발효는 제품의 색상 개선효과가 현저하였고 관능적 특성, 효소활성등이 우수하였다.

• 한국식품과학회지
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• 제25권5호
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• pp.502-509
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• 1993

3종의 재래식 고추장(순창, 보은, 사천 고추장)을 산지에서 제조, 6개월간 숙성시키면서 pH, 미생물 및 효소력 변화를 조사하였는 바 그 결과는 다음과 같이 요약되어 진다. pH의 변화는 순창과 사천 고추장의 경우 숙성초기 $4.7{\sim}4.9$에서 숙성 180일경 4.6을 보여 큰 변화가 없었으나 보은 고추장은 급격한 pH 저하로 숙성 90일 이후 pH 4를 유지하였다. 호기성 세균수는 숙성기간 동안 큰 변화가 없었고 혐기성 세균수는 숙성 120일경부터 급격히 감소하는 경향을 나타내었으며 효모는 고추장 종류에 따라 숙성 출현 시기가 달랐다. Amylase는 기질인 전분질원에 따라 효소역가가 달라졌는데 밀을 전분질로 사용한 사천 고추장의 ${\alpha}-amylase$, ${\beta}-amylase$, glucoamylase 역가가 숙성기간 전반에 걸쳐 가장 높았고 그 다음이 순창, 보은 고추장 순이었다. 재래식 고추장에서 acidic protease의 활성은 순창, 사천, 보은 고추장의 순으로 높았는데 대체로 숙성 30일${\sim}$60일경에 최대 활성을 보였다. Neutral protease의 활성은 보은, 사천, 순창 고추장의 순으로 높았는데 대체로 숙성 60일${\sim}$90일경에 최대 활성을 보였다.