• Title/Summary/Keyword: Physicochemical change

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Electrochemical Energy Storage of Milled Carbon Nanofiber (탄소나노섬유의 밀링에 따른 전기화학적 에너지 저장 특성)

  • Lee, Hye-Min;Jeon, Hyeon;Choi, Weon-Kyung;Cho, Tae-Hwan
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.4
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    • pp.527-533
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    • 2011
  • CNFs had been well addressed due to numerous promising applications in science and technology. Besides the same physicochemical properties of ordinary carbon materials such as active carbons and carbon black, they exhibit specific, e.g., tubular or fibrous structures, a large surface area, high electrical conductivity stability, as well as extremely high mechanical strengh and modulus, which make them a superior material for electrochemical capacitors. In this study, CNFs were pretreated by mechanical milling with different time in mortar and pestle. The milled CNFs were used as active material of electrode whose electrochemical property was tested to find physicochemical characterization variation. CNF electrode milled for 5 min has the highest electric capacitance. XPS spectrum were employed to explore changes in functional group induced from mechanical milling. Crystal size was calculated to analyze change of peak from different milling time by XRD. The CNF milled for 5 min has the largest crystal size and the highest electric capacitance.

Characteristics of Hamburger Patties Containing Yam Powder (마분말을 첨가한 패티의 품질특성)

  • Lee, Se-Hee;Cho, Sung-Hyun
    • Korean journal of food and cookery science
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    • v.28 no.6
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    • pp.781-787
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    • 2012
  • This study was conducted in order to observe the physicochemical and sensory characteristics of hamburger patties added with yam powder (0, 25%, 50%, 75%, and 100% of bread crumbs). Increasing the amount of yam powder in the hamburger patties tended to decrease the cooking loss rate of the weight and the diameters. The moisture content of hamburger patties ranged from 51.90 to 53.94%. Increasing the amount of yam powder in the hamburger patty tended to increase the pH and the redness (a) in the hunter color value; however, it decreased the lightness (L). For the textural characteristics, the addition of yam powder increased the hardness of the hamburger patties. In the sensory evaluation, an addition of 50% and 100% yam powder had the best score in taste as well as in the overall preference. Therefore, this result suggests that adding yam powder of 100% can be applied to the hamburger patties for preference and nutritional aspects purposes.

Effects of the Extract Yam Powder Addition on Yogurt Properties during Storage

  • Lee, Sun-Young;Ahn, Joung-Jwa;Kwak, Hae-Soo
    • Food Science of Animal Resources
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    • v.31 no.1
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    • pp.66-73
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    • 2011
  • Physicochemical and sensory properties of Dioscorea opposita Thunb. (yam) powder-added yogurts (1, 3, 5, and 7%, w/v) were examined when stored at $4^{\circ}C$ for 16 d. When the yam concentration increased, the pH increased with 16 d storage. The lactic acid bacteria counts in all yogurt samples showed an increase during storage period, and the highest counts were appeared with 7% yam powder addition. The dramatic decrease was found in viscosity with higher concentrations of yam powder-added yogurt samples. No change was found in allantoin and diosgenin contents for 16 d storage periods. A significantly strong bitterness and astringency and decreased viscosity were found with 5 and 7% yam powder addition. However, less than 3% yam powder-added yogurt samples did not show a significant difference compared with the control (p>0.05) and overall acceptability score was the highest in 3% yam powder-added yogurt throughout the storage. The present study indicated that the concentrations (1 and 3%, w/v) of yam powder could be used to produce yam powder-added yogurt without significant adverse effects on physicochemical, microbial and sensory properties, and enhance functional components from the supplementation.

The Physicochemical Characteristics of PET Fabrics Treated with Low Temperature Glow Plasma and Atmospheric Corona Discharge (진공 저온 플라즈마와 대기압 코로나 방전가공 PET 직물의 물리화학적 특성)

  • Ma, Jaehyuk;Yang, Jinyoung;Koo, Kang;Yang, Hyun A;Park, Youngmi
    • Textile Coloration and Finishing
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    • v.26 no.3
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    • pp.201-208
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    • 2014
  • The high value-added functionality for synthetic fiber can be considered through a plasma enhanced treatment. In this study, PET(Polyethyleneterephthalate) was treated with a glow plasma and corona treatment. Surface characteristics of treated fabric were investigated using electron scanning microscopy(SEM), contact angle, X-ray photoelectron spectroscopy(XPS), tensile and adhesion strength. It was found that the contact angle showed $85.5^{\circ}$ for untreated fabric, $0^{\circ}$ for plasma and corona treatment at the condition of 200W for 7min. By XPS analysis, atomic ratio of O 1s/C 1s was increased from 0.27 to 0.43 by glow plasma and 0.27 to 0.41 by corona treatment at 200W for 7min, respectively. Glow plasma and corona treatment did not significantly change the tensile strength of PET fabric. Adhesion strength showed a substantial enhancement for the surface treated with the glow plasma, while corona treatment was adversely affected.

Changes in the Physicochemical Characteristics and the Antioxidative Activity of Cheonggukjang by Addition of Walnut (호두 첨가에 따른 청국장의 이화학적 특성 및 항산화능 변화)

  • Park, Hwa-Young;Ryu, Beom-Seok;Choi, Ung-Kyu
    • The Korean Journal of Food And Nutrition
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    • v.28 no.6
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    • pp.1004-1010
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    • 2015
  • This study was conducted to investigate the changes in the physicochemical characteristics and antioxidant activity of cheonggukjang with the addition of walnuts. The pH of cheonggukjang did not change significantly with the addition of walnut. But the water content decreased significantly. Walnut addition to the soybean was expected to have a positive effect because the number of Bacillus subtilis was not reduced. The viscous substance content was significantly decreased when more than 20% of walnut was added to cheonggukjang. The addition of walnut made the color darker. The flavonoid and polyphenol content was sharply increased in proportion to the walnut addition and the DPPH radical scavenging activity of cheonggukjang also increased. Altogether, it was found that the addition of walnut had a positive influence on the cheonggukjang by increasing the antioxidant activity.

Physicochemical and Sensory Textural Properties of Rice Extrudate Depending on Extrusion Conditions

  • Chung, Kang-Hyun
    • Preventive Nutrition and Food Science
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    • v.5 no.1
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    • pp.25-31
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    • 2000
  • Extrusion conditions for production of rice extrudate were studied. The optimal production conditions of rice extrudate were determined by the relationship between dependent variables such as expansion ratio, shear strength and color change and independent variables such as moisture content of raw material, screw speed, and die tem-perature of extruder. The textural quality of rice exturdate was significantly affected by the moisture content of raw material (x1), screw speed (x2), and die temperature (x3) of extruder. The expansion ratio of rice extrudate showed the highest value at the moisture content of 18% of raw material, and the lowest at 24%, and whose regression equation was Y=34.8967 - 3.219X1 - (0.623$\times$10-2)X2 + 0.136X3 + (0.648$\times$10-1)X12 + (0.138$\times$10-3)X1X2 + (0.456$\times$10-4)X22 + (0.719$\times$10-3)X1X3 -(0.515$\times$10-3)X2X3- (0.552$\times$10-3)X32. The most desirable texture of rice extrudate determined by shear test and sensory evaluation was obtained at the following conditions : mois-ture content of 18% of raw material, screw speed of 210 rpm and die temperature of 11$0^{\circ}C$. The rice extrudate prepared under the above conditions showed the lowest shear force of 954g at which the highest sensory score was obtained.

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Comparison of Meat Quality and Physicochemical Characteristics of Pork between Korean Native Black Pigs (KNBP) and Landrace by Market Weight (출하체중에 따른 재래돼지와 랜드레이스의 도체 및 돈육의 이화학적 특성 비교)

  • Park, J.C.;Kim, Y.H.;Jung, Hyun-Jung;Park, B.Y.;Lee, J.I.;Moon, H.K.
    • Journal of Animal Science and Technology
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    • v.47 no.1
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    • pp.91-98
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    • 2005
  • Results of meat quality, physicochemical characteristics, fatty acid and amino acid composition of the Korean Native Black Pig(70 and 90 kg of slaughter weight; KNBP) versus Landrace(110kg of slaughter) are as below. Compared with Landrace, the KNBP exhibited a greater lean meat yield, with no difference in backfat thickness between Landrace and KNBP. There were no difference in chemical composition between Landrace and KNBP, but pH, and cooking loss in the KNBP were superior value than those of the Landrace. These results, KNBP were affected in sensory property and cooking yield. Amino acid content of KNBP and Landrace were significant differences between Landrace and KNBP. Except for the methionine, essential amino acid contents of KNBP had significantly higher than those of Landrace. In the change of fatty acid composition, the Landrace had significantly higher percentages of palmitic(l6: 0), stearic(18: 0) and linolenic(18: 3) acids than that of KNBP, but linoleic acid(l8: 2) was decreased.

Release Pattern of Urea from Metal-urea-clay Hybrid with Montmorillonite and Its Impact on Soil Property

  • Kim, Kwang-Seop;Choi, Choong-Lyeal;Lee, Dong-Hoon;Seo, Young-Jin;Park, Man
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.4
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    • pp.545-550
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    • 2011
  • Urea intercalated into montmorillonite (MT) exhibits remarkably enhanced N use efficiency, maintaining its fast effectiveness. This study dealt with the release property of urea from metal-urea-clay hybrid with MT (MUCH) under continuous-flow conditions and the cumulative impacts of its successive application on physicochemical properties of soils. Releases of urea were completed within 4 hrs under continuous-flow condition regardless of the types and the leaching solutions. However, urea release property was significantly affected by both the form of fertilizer and the presence of electrolytes in solution. The fast release property of urea from MUCH in continuous-flow condition was not significantly affected by soil properties such as soil pH and soil texture. In addition, its successive application did not lead to any noticeable change in soil physicochemical properties, water stable aggregate rate, water holding capacity and cation exchange capacity in both sandy loam and clay loam soils. Therefore, this study strongly supported that urea intercalated into MT could be applied as fast-effective N fertilizer, in particular for additional N supply.

Physicochemical Characteristics of Cold-Brew Kenya AA according to Cold Extraction Conditions (케냐AA의 냉추출에 따른 이화학적 변화)

  • Kim, Ki Myong
    • The Korean Journal of Food And Nutrition
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    • v.32 no.5
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    • pp.504-510
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    • 2019
  • The purpose of this study was to compare the effects of soaking and ultrasonic extraction by observing the change of contents with extraction time of physicochemical properties (solid content, colorness, caffeine, chlorogenic acid, total polyphenols, DPPH, and ABTS). As a result of the analysis, solid content increased with longer extraction time and the whiteness tended to decrease with longer extraction time. Conversely, the extraction of functional materials showed a tendency to increase as the extraction time increased. Caffeine reached the maximum value after two hours soaking, but showed the same result as one hour for sonication. Chlorogenic acid did not show difference from the content of coffee extracted for one hour soaking only by sonication extraction for 30 minutes. The total polyphenols eluted with approximately two hours of soaking even after 30 minutes of sonication. DPPH and ABTS were insignificant in their concentrations, but their antioxidative effect was more than two hours of soaking with only 30 minutes of sonication. Sonication has a short time extraction from a functional aspect (caffeine content, chlorogenic acid, polyphenol content, and antioxidant capacity) and this experiment can provide basic data for the development of innovative recipes.

Sensory and Physicochemical characteristics and Storage time of Daechu-Injeulmi added with various levels of chopping jujube (다진 대추를 첨가한 대추인절미의 관능적, 이화학적 특성과 저장성 연구)

  • 차경희;이효지
    • Korean journal of food and cookery science
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    • v.17 no.1
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    • pp.29-42
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    • 2001
  • The purpose of this study was 10 investigate the effect of jujube on the physicochemical properties of lnjeulmi during storage. Various lnjeulmi samples were prepared with steamed glutinous rice, glutinous rice flour, or brown glutinous rice flour along with the addition of chopped jujube at 3, 6, 9, or 12% of rice. In sensory evaluation, the more jujube was added, the stronger sweetness and bitterness were obtained. The samples made with steamed glutinous rice gave the harshest texture. Tenderness and moistness of Deachu-Injeulmi were the highest in the samples made with glutinous rice followed by brown glutinous rice flour, and glutinous rice flour, and they were increased with less amount of jujube. The chewiness of the samples made with brown glutinous rice flour' was the highest and the samples made with glutinous rice were the coarsest. The more jujube was added, the redness and yellowness of Daechu-Injeulmi were increased. The moisture content was higher in the samples made with glutinous rice followed by glutinous rice flour and brown glutinous rice flour. The reducing sugar content of samples during storage was higher in the order of glutinous rice, glutinous rice flour, and brown glutinous rice flour, and it was dramatically reduced until 48hr of storag e; however, it was increased a little bit after 72 hr. The degree of gelatinization was reduced rapidly during the first 24hr of storage, and it was decreased in the order of brown glutinous rice flour, glutinous rice flour, and glutinous rice. The springiness and cohesiveness were decreased during storage. The chewiness and gumminess were increased with the increase of added jujube, and they were increased until 24hr of storage, then decreased after 48hr. The hardness was the highest in the samples made with glutinous rice and 12% of chopped jujube showed the least change in the hardness. The more jujube was added, the less change in the hardness of samples was observed during storage, consequently retarded the speed of retrogradation

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