• Title, Summary, Keyword: Microwave

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The Effects of Microwave Heating on the Texture of Sugared Chestnuts (Microwave 가열이 밤 당침제품의 물성에 미치는 영향)

  • Hwang, Tae-Young;Kim, Joon-Han;Kim, Jong-Kuk;Moon, Kwang-Deog
    • Korean Journal of Food Science and Technology
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    • v.30 no.3
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    • pp.569-573
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    • 1998
  • This study was conducted to investigate the differences of textural characteristics and microstructure of sugared chestnuts between heated by a heater and microwave. Raw chestnuts were boiled and infiltrated the sugar in sugar syrup by heating. The content of WSP (water soluble pectin) was increased, but HSP (hydrochloric acid soluble pectin) was decreased by boiling and sugaring. This change was remarkable when it was boiled and sugared by a microwave heating. The hardness, gumminess and chewiness were more decreased in the sugared chestnut boiled and sugared with a microwave than that processed with a heater. Microstructure of sugared chestnut processed with a microwave heating showed the distruction of cell wall.

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Microwave-assisted Photocatalytic Degradation of Methylene Blue (마이크로웨이브가 부가된 광촉매에 의한 메틸렌블루의 분해)

  • Kim, Yu-Bong;Jo, A-Ra;Ra, Deog-Gwan;Park, Jae-Hyeon;Kim, Sun-Jae;Jung, Sang-Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.8
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    • pp.817-822
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    • 2008
  • In this study, the photocatalytic degradation of methylene blue in TiO$_2$ particles-dispersed water solution was carried out by irradiating microwave and UV light simultaneously. A microwave-discharged electrodeless UV lamp was developed to use microwave and UV simultaneously for photocatalytic reactions. The results of photocatalytic degradation of methylene blue showed that the decomposition rate increased with the microwave intensity, the circulating fluid velocity, and the amount of TiO$_2$ particles and auxiliary oxidizing agents added. Especially, the rate constant of H$_2$O$_2$-added photocatalytic reaction increased about three times from 0.0075 min$^{-1}$ to 0.0250 min$^{-1}$ when microwave was additionally irradiated. This study demonstrates that the microwave irradiation can play a very important role in photocatalytic degradation using peroxides although it is not easy to quantitatively assess the effect of microwave on photocatalytic reactions from the experimental data of this study.

Design and Fabrication of a Dual Cylindrical Microwave and Ohmic Combination Heater for Processing of Particulate Foods

  • Lee, Seung Hyun;Choi, Won;Park, Sung Hee;Jun, Soojin
    • Journal of Biosystems Engineering
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    • v.40 no.3
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    • pp.250-260
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    • 2015
  • Purpose: Dual cylindrical microwave chambers equipped with an ohmic heating tube were designed and fabricated to maximize the electric field strength for expeditious heat treatment of particulate foods. Methods: The efficacy of the combination heater was investigated by simulating the electric field distribution by using COMSOL Multiphysics software. Results: All components of the designed microwave heating unit were suitable for transmitting maximal microwave power to the load. The simulated electric field distribution implied that single-mode microwave heating would be sufficient for the steady generation of a highly localized heating zone in the cavity. During impedance matching, the calculated reflection coefficient ($S_{11}$) was small, possibly implying minimal power loss and wave reflection in the designed microwave heating chamber. Conclusions: This study demonstrates the possibility of concentrating the microwave power at the centerline for a single-frequency microwave, for thermal treatment of multiphase foods without attenuating the microwave power.

Effect of Microwave Treatment on the Antioxidant Activity of Rice Processed By-products (Microwave처리에 의한 쌀 가공 부산물의 항산화능의 변화)

  • 배성문;김정한;조철우;정태춘;하정욱;이승철
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.6
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    • pp.1026-1032
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    • 2001
  • Microwave treatment was studied to investigate the antioxidant ability of rice hull and rice bran. The color changes were related to the intensity of microwave and to the treated time on rice bran. However, the electron donating abilities of rice hull and rice bran extract were not much affected by microwave intensity. Rice hull extract treated with a 100 W microwave showed 80% inhibition of lipid peroxidation when fish oil was treated with $H_2O$$_2$. Also inhibition activity against lipid peroxidation in rice hull is more stable than that of rice bran when treated with microwave. Overall, rice hull extract showed better antioxidant activity than rice bran. It seems that rice hull contains higher antioxidant components as well as the browning reaction products having anti-oxidant activity during microwave treatment.

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A Case of the Laryngopharyngeal Burn Caused by A Microwave-Heated Egg Bite

  • Won, Seong Jun;Woo, Seung Hoon
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.24 no.2
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    • pp.122-124
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    • 2013
  • Nowadays, microwave ovens are commonly used for cooking. However, the cooking certain food in microwave ovens can be hazardous. It has been reported that the heating eggs in a microwave oven can cause an explosion and injuries. The exploding eggs can cause burn injury of face, neck, eyelid, pharynx and larynx. Direct thermal damage to the larynx after swallowing microwave-heated eggs is rare. The authors report a larynx thermal injury due to microwave-heated eggs and review the cause and the prevention methods of exploding eggs.

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Optimization of Microwave Extraction Conditions for Flammulina velutipes by Response Surface Methodology (반응표면분석에 의한 팽이버섯의 microwave 추출조건 최적화)

  • Kim, Hyun-Ku;Kim, Mi-Ok;Choi, Mal-Gum;Kim, Kong-Hwan
    • Korean Journal of Food Science and Technology
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    • v.35 no.2
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    • pp.222-228
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    • 2003
  • Optimum extraction conditions for yield, browning color, electron-donating ability, nitrite-scavenging effect, total polyphenol content, and tyrosinase-inhibitory activity of Flammulina velutipes were determined using response surface methodology through central composite design. Yield of F. velutipes was affected by ethanol concentration, and browning color improved more with the increase of ethanol concentration than microwave power. Nitrite-scavenging effect was improved with increasing ethanol concentration and decreasing microwave power. Electron-donating ability and total polyphenol content were improved with increasing ethanol concentration and microwave power. Tyrosinase-inhibitory effect increased more with decrease in microwave power than with ethanol concentration. The optimal range of extraction conditions for effective component of F. velutipes were $47.21{\sim}76.05$ watt of microwave power, $10.25{\sim}43.56%$ of ethanol concentration, and 5.72 min of extraction time.

Quality Characteristics of Instant Nuroong-gi Prepared Using a Microwave (Microwave를 이용한 즉석 누룽지의 품질특성)

  • Lee, Hyun-Seok;Kwon, Ki-Hyun;Kim, Jong-Hoon;Cha, Hwan-Soo
    • Korean Journal of Food Preservation
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    • v.16 no.5
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    • pp.669-674
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    • 2009
  • We prepared puffed instant Nuroong-gi samples using a microwave and investigated the physicochemical characteristics of the products. The quality of Nuroong-gi prepared using a microwave was compared with that of noodles prepared in a steam cooker and pressure cooker in terms of moisture content, color, water binding capacity ratio, viscosity, sedimented volume of insoluble solids, turbidity, and sensory evaluation. The moisture content of Nuroong-gi prepared in a microwave was similar to that of steam cooker and pressure cooker samples. The color (lightness) of steam cooker-prepared noodles was greater than that of noodles cooked using other modes. The water binding capacity ratio fell with increasing microwave cooking time. The viscosity of noodles prepared using a microwave was higher than that of pressure cooker samples and lower than that of steam cooker noodles. The sedimented volume of insoluble solids and turbidity increased with a rise in cooking temperature. Nuroong-gi prepared in a microwave scored higher in sensory evaluation tests than did steam cooker or pressure cooker samples. These results indicate that Nuroong-gi preparation using a microwave is very efficient.

Microwave-assisted Protein Digestion on Various Locations of a Microplate

  • Lee, Ji-Hye;Park, Se-Hwan;Lee, Sun-Young;Hong, Jang-Mi;Park, Kyu-Hwan;Kim, Hyun-Sik;Kim, Jeong-Kwon
    • Mass Spectrometry Letters
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    • v.2 no.4
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    • pp.84-87
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    • 2011
  • The effectiveness of microwave-assisted protein digestion in different well positions of a 96-well microplate was investigated where microwave-assisted protein digestion of bovine serum albumin was performed in 10 different wells of a 96-well microplate in a microwave oven. Similarly increased sequence coverages (~70%) were generally observed for the 10 microwave-assisted protein digestion samples compared to conventional overnight digestion (63%), which is possibly due to higher miscleavage ratios (~53%) of the samples from microwave-assisted protein digestion than conventional overnight digestion (42.1%). The reproducible results of microwave-assisted digestions from different well positions demonstrate the potential of high-throughput analysis of proteins using microwave-assisted protein digestion.

Synthesis and Characterization of Some Quinazoline Derivatives as Potential Antimicrobial Agents under Microwave Irradiation

  • Mehta, Sarika;Swarnkar, Neelam;Vyas, Madhuri;Vardia, Jitendra;Punjabi, Pinki B.;Ameta, Suresh C.
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2338-2343
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    • 2007
  • Under the framework of green chemistry, an efficient and extremely fast procedure for the synthesis of 5a-h through four-step procedure starting from 2-arylidenetetralin-1-one 1a-d under microwave irradiation is described. A considerable increase in the reaction rate has been observed with better yield. The structures of the synthesized compounds have been characterized on the basis of their elemental analysis and spectral data. Synthesized compounds 5a-h was evaluated for their antimicrobial activity. Some of the compounds exhibited appreciable activity.

Effect of Microwave Reheating on the Quality of Cooked Rice (마이크로파 재가열이 쌀밥의 품질에 미치는 영향)

  • Kum, Jun-Seok;Han, Ouk;Kim, Yong-Hwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.3
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    • pp.504-512
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    • 1996
  • Changes in quality of cooked rice after microwave reheating were evaluated. Ceramic coated microwave oven reduced a reheating time(1 min). Storage temperature, storage time and microwave reheating did not affect the color value of cooked rice after microwave reheating. Hardness of cooked rice after microwave reheating decreased in frozen storage treatment. Photomicrographs of cross-section of cooked rice after microwave reheating showed restoration of starch. Effect of storage temperature and time were not significant in appearance, aroma, taste and texture of cooked rice after microwave reheating for sensory evaluation test.

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