• Title, Summary, Keyword: water activity

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Moisture Sorption Isotherm and Quality Deterioration of Dry Jujube (건대추의 등온흡습곡선 및 품질열화특성)

  • 김영숙;안덕순
    • Korean Journal of Food Preservation
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    • v.4 no.1
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    • pp.33-38
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    • 1997
  • In order to provide informations for designing packaging and storage condition of dry jujube (Zizyphus jujuba MILLER), moisture sorption isotherm was determined for temperatures of 20, 30 and 4$0^{\circ}C$, and quality changes were evaluated as function of temperature and water activity. Dry jujube at a given water activity showed higher equilibrium moisture content for lower temperature. Moisture isothem could be fitted by GAB model equation, giving higher C value, lower m0 and relatively constant k value with increase in temperature. Ascorbic acid was lost more highly at higher temperature and water activity, and showed negligible retention for whole range of water activity and temperature studied after 141 days. Browning increased with water activity up to 0.73 at 30 and 4$0^{\circ}C$. Dry jujube of high water activity had high L value in surface color, which represent brightness of surface color. Considering quality retention in the storage, dry jujube is desired to be dried to water activity of 0.42 and be stored at temperature below 3$0^{\circ}C$

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The Effect of Seasonal Change in Characteristics of Hygiene Activity on Domestic Hot Water Energy Consumption (거주자 위생활동 특성의 계절적 변화가 급탕 에너지 소비량에 미치는 영향)

  • Park, Kwang-il;Kwak, In-Gyu;Mun, Sun-Hye;Huh, Jung-Ho
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.5
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    • pp.51-58
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    • 2018
  • The purpose of this study was to analyze the effect of seasonal change in characteristics of hygiene activity on domestic hot water energy consumption. With 16 residents of 4 households, the data about frequency of hygiene activity and water temperature was collected from February to August, 2017. The results of collected data discovered that the frequency of hygiene activity was higher especially in summer, whereas the consumption of warm water they used was higher in winter. The seasonal change in characteristics of hygiene activity was analyzed to be changed and strongly influenced by outdoor temperature. The influence of characteristics of hygiene activity on hot water consumption was analyzed. There was 13% of difference between consumption that was calculated taking characteristics of hygiene activity into account and consumption that was not. Therefore, this study suggested hygiene activity schedule, hot water profile and hot water consumption pattern, which can be utilized for improving simulation as well.

Studies on the Biological Activity of Astragalus membranaceus Extracts

  • Kim, Jun-Ho
    • Biomedical Science Letters
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    • v.18 no.1
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    • pp.35-41
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    • 2012
  • Physiological activities of hot water extract and solvent fractions isolated from Astragalus membranaceus were examined and the antioxidative, fibrinolytic, thrombin inhibitory and a-glucosidase inhibitory activity were measured. The hot water extract of Astragalus membranaceus was fractionated into hexane, chloroform, ethyl acetate, butanol and water fractions, and each of these fractions was individually assayed. The antioxidative activities of ethyl acetate and chloroform fractions were 89.96% and 87.36%, respectively. Using the fibrin plate method, only the hot water extract showed a plasmin activity of 0.41 units/ml. The thrombin inhibitory activity of the ethyl acetate fraction was the highest with a value of 82.73%. The hot water extract displayed a-glucosidase inhibitory activity of 64.91%. In conclusion, the hot water extract and the ethyl acetate fraction can be used as materials for the development of biofunctional foods to prevent cardiovascular diseases.

Physiological Effects of Hot Water Extract and Solvent Fractions of Carthamus tinctorius L.

  • Kim, Jun-Ho
    • Biomedical Science Letters
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    • v.17 no.2
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    • pp.157-165
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    • 2011
  • In this study, we investigated the biological activities of Carthamus tinctorius including antioxidative, fibrinolytic, thrombin inhibitory, ${\alpha}$-glucosidase inhibitory and collagenase inhibitory activities. Carthamus tinctorius, hot water extract was fractionated into hexane, chloroform, ethyl acetate, butanol and water fraction. Each of these was assayed individually. The hot water extract showed high antioxidative activity and thrombin inhibitory activity at 90.17% and 97.10% respectively. In the fraction activity tests, chloroform fraction showed the highest antioxidative activity at 81.85%. The fibrinolytic activity was strong only in the butanol fraction at 0.70 plasmin units/ml. The thrombin inhibitory activities of hexane, ethyl acetate and butanol fractions were 97.35%, 86.74% and 93.18% respectively. In collagenase inhibitory activity test, hexane fraction showed the highest activity at 87.78%. In conclusion, the hot water extract and solvent fractions of Carthamus tinctorius L can be used as a material for the development of biofunctional tea and foods respectively.

Antioxidant activity and analysis of proantbocyanidins from pine (Pinus densiflora)needles

  • Park, Yong-Soo;Jeon, Min-Hee;Hwang, Hyun-Jung;Park, Mi-Ra;Lee, Sang-Hyeon;Kim, Sung-Gu;Kim, Mi-Hyang
    • Nutrition Research and Practice
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    • v.5 no.4
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    • pp.281-287
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    • 2011
  • In this study, we evaluated the antioxidant activity of pine needle extracts prepared with hot water, ethanol, hexane, hot water-hexane (HWH), and hot water-ethanol (HWE), using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical method. The hot water extract possessed superior antioxidant activity than the other extracts. We also compared the antioxidant activity of pine needle extracts through ROS inhibition activity in a cellular system using MC3T3 E-1 cells. The hot water extract exhibited the lowest ROS production. The pattern of HPLC analysis of each extract indicated that the hot water extract contained the highest proanthocyanidin level. The pine needle hot-water extract was then isolated and fractionated with Sephadex LH-20 column chromatography to determine the major contributor to its antioxidant activity. The No.7 and 12 fractions had high antioxidant activities, that is, the highest contents of proanthocyanidins and catechins, respectively. These results indicate that the antioxidant activity of procyanidins from the hot water extract of pine needles is positively related to not only polymeric proanthocyanidins but also to monomeric catechins. Moreover, the antioxidant activity of the pine needle hot water extract was similar to well-known antioxidants, such as vitamin C. This suggests that pine needle proanthocyanidins and catechins might be of interest for use as alternative antioxidants.

Kinetics of Initial Water Vapor Adsorption by Inonotus obliquus Mushroom Powders

  • Lee, Min-Ji;Seog, Eun-Ju;Lee, Jun-Ho
    • Preventive Nutrition and Food Science
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    • v.12 no.2
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    • pp.111-114
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    • 2007
  • Water vapor adsorption kinetics of Inonotus mushroom powders were investigated in temperature and water activity ranges of 20 to 40$^{\circ}C$ and 0.30 to 0.81, respectively. Initial water vapor adsorption rate of mushroom powders increased with increases in temperature and water activity. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Water vapor adsorption kinetics of the mushroom powders can be well described by a simple empirical model. Temperature dependency of the reaction rate constant followed the Arrhenius relationship. The activation energy ranged from 56.86 to 91.35 kJ/mol depending on water activity. Kinetic compensation relationship was observed between k$_o$ and E$_a$ with the isokinetic temperature of 790.27 K.

Drinking Wateres Effects on Tyrosinase Activities (물리 Tyrosinase의 활성도에 미치는 영향)

  • Rhee, Byung-Chul;Lee, Zong-Liong;Lee, Duk-Soo;Kim, Yil
    • Journal of Environmental Health Sciences
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    • v.22 no.1
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    • pp.1-4
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    • 1996
  • I have conducted two testings to find out which water is better for drinking water. First, I made 20 mM L-DOPA solutions by solving L-DOPA (3,4-Dihydroxyphenylalanine) in tap water, Waters' mineral water and reverse osmotic water. Then I measured activities after adding Tyrosinase (purifide enzyme, step 3), which was extracted from Salanum melongena(mad apple), in each L-DOPA solution. Second, I solved 0.1, 0.5 and 0.9% salt in each 20 mM L-DOPA distilled water to measure activity of each salt solution. The results of the testings are as follows: 1. 10 minutes after adding Salanum melongena(mad apple) tyrosinase in each L-DOPA solution, activity of Waters' mineral water was 0.867 tap water 0.777 and reverse osmotic water 0.742. 2. Activity of Waters' mineral water was higher than that of tap water by 10.4% and higher then reverse osmotic by 14.4%. 3. Activity of Waters' mineral water was much higher than that of 0.9% salt water by 41.8%. 4. The optimum pH of Salanum melongena (mad apple) tyrosinase is 9.0. Most enzymes working in the human metabolism are alkaline and body fluids' pH also alkaline. In conclusion, an alkaline water is believed better than an acidic water for drinking.

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Antioxidant and Anti-Inflammatory Activities of Extracts from Eugenia caryophyllata Thunb. (정향 열수 및 에탄올 추출물의 항산화 및 항염 효과)

  • Oh, Hee-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.31 no.5
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    • pp.481-488
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    • 2016
  • The objective of this study was to investigate the antioxidant and anti-inflammatory activities of Eugenia caryophyllata Thunb. water and 70% ethanol extracts. The content of total polyphenol was significantly higher in water extract than in 70% ethanol extract. The DPPH radical scavenging activity of water extract was similar to that of Vit. C at a concentration of $1,000{\mu}g/mL$. The ABTS radical scavenging activities of water and 70% ethanol extract were similar to that of Vit. C at a concentration of $1,000{\mu}g/mL$. SOD-like activity of water extract was higher than that of 70% ethanol extract at a concentration of $1,000{\mu}g/mL$ but lower than that of Vit. C. The DPPH radical scavenging activity, ABTS radical scavenging activity, and SOD-like activity increased as concentrations of water and 70% ethanol extracts increased. Cell cytotoxicity was not observed at all concentrations except at $100{\mu}g/mL$ concentration of water extract. Inhibitory activity on NO production effect of water extract was significantly higher than that of 70% ethanol extract. These results show that E. caryophyllata Thunb. has potent biological activities, and their activities were different depending on extraction solvent.

Effect of Salvia plebeia Water Extract on Antioxidant Activity and Lipid Composition of Rats Fed a High Fat-High Cholesterol Diet (배암차즈기 열수 추출물 첨가가 고지방-고콜레스테롤 식이를 급여한 흰쥐의 항산화 활성과 지질조성에 미치는 영향)

  • Won, Hyang Rye
    • The Korean Journal of Community Living Science
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    • v.27 no.2
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    • pp.233-243
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    • 2016
  • This study examined the antioxidant activity and lipid composition of rats fed a high fat-high cholesterol diet containing Salvia plebeia water extract. Three levels (50 mg/kg, 200 mg/kg, 500 mg/kg) of Salvia plebeia water extract were administered to seven weeks old male Sprague Dawley rats for four weeks. The activity of glutathione peroxidase in serum was high in all groups that received the Salvia plebeia water extract (p<0.05). The glutathione reductase activity was high (p<0.05) in groups that received 50 mg/kg and 500 mg/kg of Salvia plebeia water extract. When rats received Salvia plebeia water extract, the content of MDA (malondialdehyde) in the serum and liver was low in all groups. In addition, the serum total lipid, triglyceride, total cholesterol and LDL-cholesterol contents decreased significantly (p<0.05). Total cholesterol and triglyceride levels in the liver were significantly lower in the group that received the Salvia plebeia water extract than in the control group (p<0.05). Salvia plebeia water extract improves lipid metabolism and it almost meets with the increase of antioxidant activity and peroxide formation reduction. Based on these results, supplemented of a high fat-hypercholesterol diet with Salvia plebeia can increase antioxidant activity and depress peroxide formation in serum, as well as liver cholesterol and triglycerides.

Metal Ions' Effect on Activity of Pine Needle Tyrosinase (금속이온이 솔잎 tyrosinase의 활성에 미치는 영향)

  • Lee, Zong-Liong;Lee, Duk-Soo;Kim, Yil
    • Journal of environmental and Sanitary engineering
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    • v.13 no.1
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    • pp.157-165
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    • 1998
  • The purpose of this study is to explain the relations between pine needle tyrosinase's activity and quantity of minerals in the Waters' mineral water. Pine needle tyrosinase's activity was measured by metal ions' concentration like Ca, Mg, Na, K, and Fe in different kinds of drinking water. 1. Pine needle tyrosinase has the highest activity when Ca's concentration is 14.40mg/L while the activity decreases by 92% when it is 108.10 mg/L. Therefore, the resonable range of Ca concentration for drinking water is 10-100.0 mg/L. 2. Mg has higher Pine needle tyrosinase's activity than Ca by three times. The reasonable range of Mg concentration for drinking water is 3.0-10.0 mg/L. 3. Pine needle tyrosinase has the highest activity when Na's concentration is 15.70 mg/L. The reasonable range of Na concentration for drinking water is less than 15 mg/L. 4. The activity increases as K concentration rises. In normal kinds of drinking water, K concentration is less than 10 mg/L. Since K has impacts on the activity only when its concentration is more than 10 mg/L, no problem in expected. 5. Fe has some impacts on the activity when its concentration is more than 10mg/L. As most kinds of drinking water contain less than 0.3 mg/L, no problem is expected. With above-mentioned observations, it is concluded that Water's mineral water contains reasonable levels of minerals like Ca, Mg, K and Na.

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