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Microwave Heating (microwave + heating)
Kinds of Microwave Heating Selected AbstractsCOMPUTER-CONTROLLED MICROWAVE HEATING TO IN-PACKAGE PASTEURIZE BEEF FRANKFURTERS FOR ELIMINATION OF LISTERIA MONOCYTOGENES,JOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2005LIHAN HUANG ABSTRACT The objective of this study was to develop an in-package pasteurization technology to kill Listeria monocytogenes in ready-to-eat meats using microwave heating. This technology utilized an infrared sensor to monitor the surface temperature of beef frankfurters during microwave heating. The aim was to increase the surface temperature of frankfurters to a set point lethal to L. monocytogenes. A feedback control mechanism was used to control the power to the microwave oven. Results indicated that the simple on-off control mechanism was able to maintain the surface temperature of beef frankfurters near the respective set points of 75, 80 or 85C used in this study. This pasteurization process was able to achieve a 7-log reduction of L. monocytogenes in inoculated beef frankfurters using a 600-W nominally rated microwave oven within 12,15 min. If optimized, this system may provide the food industry with a terminal, postlethality pasteurization technology to kill L. monocytogenes in ready-to-eat meats within the final packages. [source] DEVELOPMENT and EVALUATION of MICROWAVE HEATING of APPLE MASH AS A PRETREATMENT to PRESSINGJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2004J.S. ROBERTS ABSTRACT Fuji, McIntosh, and Red Delicious apple mashes were heated in a 2450 MHz oven to achieve bulk temperatures of 40, 50, 60, and 70C. Three kilograms of mash at a depth of 0.016 m heated using 1500 W were the optimum parameters to heat apple mash in the microwave. Variety of the apple mash was shown not to have a significant effect on the heating performance. Comparing actual bulk temperature to the predicted bulk temperatures of 40, 50, 60, and 70C showed reproducibility of heating these mashes using microwave energy. Average variation between actual and predicted bulk temperatures were 1.48C for the Fuji mash, 0.98C for the McIntosh mash, and 1.13C for the Red Delicious mash. In addition, regional heating was investigated and four distinct regions of heating were observed: the corner, the edge, the middle, and the center. Color and moisture content of the mash were also measured and compared to unheated mash at 21C. [source] EXTRACTION YIELD OF SOLUBLE PROTEIN AND MICROSTRUCTURE OF SOYBEAN AFFECTED BY MICROWAVE HEATINGJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2006IL CHOI ABSTRACT A laboratory-scale microwave (MW)-assisted extraction system was constructed and compared with a conventional shaking water bath regarding the extraction of soluble proteins in soybeans. Dynamic reaction was monitored by response surface methodology in the MW-assisted extraction system. The yield of soluble protein increased until either temperature (T) or water/solid (W/S) ratio reached an optimum point (60.1C, 12.6 mL/g), and then decreased with further increase of T or W/S ratio. In addition, the yield of soluble protein increased with time within a range of 30 min, and no critical point was observed. The molecular mass of soluble protein was distributed from 19.3 to 81.3 kDa estimated by sodium dodecyl sulfate,polyacrylamide gel electrophoresis. Scanning electron microscopy showed the destruction of the microstructure of soybean cells, which increased the extraction of soluble soy protein. [source] Temperature Profiles in a Cylindrical Model Food During Pulsed Microwave HeatingJOURNAL OF FOOD SCIENCE, Issue 7 2001H.W. Yang ABSTRACT: Cylindrical 2%-agar gel samples were heated by pulsed and continuous microwave applications. The total microwave application time of 3 min was maintained for all experiments. Sample temperature was measured at various depths along the radial dimension to experimentally determine the internal temperature profile as a function of heating time. A local hot spot was observed at the center portion of the sample during the continuous microwave application. This hot spot was less significant during pulsed microwave applications, especially when longer intermittent power-off times were employed. An implicit finite-difference model was used to estimate temperature profiles within the sample during microwave heating. The estimated temperature profiles matched the experimental values well. [source] Photoluminescent Properties of SrTiO3:Pr, Al Nanophosphors Synthesized by Microemulsion,Microwave HeatingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2007Qi Pang A novel approach for the preparation of SrTiO3:Pr, Al nanophosphors by microemulsion,microwave heating is reported in this paper. In comparison with the conventional solid-state sintering processes, this novel method provides a limited small space in a micelle for the formation of nanosized precursors and requires a very short heating time, thus reducing the energy consumption. As a result, small-sized particles with a narrow size distribution and high purity were produced. Transmission electron microscopy characterizations indicated that the synthesized particles were almost spherical with an averaging diameter of ,24 nm and agglomerates slightly. The X-ray diffraction analysis revealed the perovskite cubic structure of SrTiO3:Pr3+ nanoparticles. The luminescent of SrTiO3:Pr, Al phosphors were investigated by photoluminescence. Under 350 nm excitation, SrTiO3:Pr, Al showed a strong red emission, peaking at around 615 nm. The photoluminescence excitation intensity was enhanced by the addition of Al3+ ions. [source] Synthesis of Mixed Conducting Ceramic Oxides SrFeCo0.5Oy Powder by Hybrid Microwave HeatingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2002Di Huo Mixed conducting ceramic oxide SrFeCo0.5Oy powders were prepared by a conventional solid-state reaction method and two types of hybrid microwave heating methods. XRD, SEM/EDS (energy-dispersive spectroscopy), and TEM/EDX (energy-dispersive X-ray microanalysis) were used to characterize the products. The conventional heated sample is a three-phase mixture composed of a predominant orthorhombic Sr4(Fe1,xCox)6O13±, phase, a cubic perovskite SrFe1,xCoxO3,, phase, and a CoO phase. Phase components of the direct hybrid heated samples are similar to those of the conventional heated sample, except that its predominant phase is a cubic perovskite SrFe1,xCoxO3,, phase other than the orthorhombic Sr4(Fe1,xCox)6O13±, phase. The indirect hybrid heated sample is mainly composed of a cubic perovskite Sr(Fe,Co)1.5Oy phase, with a trace amount of orthorhombic phase and spinel (Fe,Co) oxides. The cobalt content of the Sr(Fe,Co)1.5Oy phase is much higher than that of the SrFe1,xCoxO3,, phase. Particle size distribution of the conventional heated sample is very wide. The indirect hybrid heated sample has a relatively narrow particle size distribution, with an average particle size of 3,4 ,m, but the particles stick to form agglomerates. The morphology of the direct hybrid heated sample is similar to that of the conventional heated sample, except that submicrometer grade particles were rarely observed. [source] Morphology and High Modulus of Laminated Ultra-Drawn Polyethylene Films with Biaxial Orientation Prepared by Microwave HeatingMACROMOLECULAR MATERIALS & ENGINEERING, Issue 7 2007Mami Azuma Abstract To improve the poor mechanical properties of uniaxially ultra-drawn films along the transverse direction, lamination of two ultrahigh molecular weight polyethylene/ethylene dimethylaminoethyl methacrylate copolymer blend films was carried out in the rectangular elongation direction by a microwave heating method. The characteristics of the successful laminated films were analyzed theoretically and experimentally. The original orientation of the crystallites for the blend films was maintained perfectly after lamination, and the preferential directions intersected each other. The Young's modulus increased symmetrically with respect to the 45 ° direction. This is the first report concerning a drastic improvement of the Young's modulus in the transverse direction for films ultra-drawn along one direction. [source] ChemInform Abstract: Accelerated Heck Reaction Using ortho-Palladated Complex with Controlled Microwave Heating.CHEMINFORM, Issue 16 2010Abdol R. Hajipour Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Triselenium Dicyanide (TSD): A New Catalyst for the Facile Synthesis of Heteroins Including Pteroin and Quinoxaloin under Microwave Heating.CHEMINFORM, Issue 50 2009Shyamaprosad Goswami Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Poly(ethyleneglycol): A Versatile and Recyclable Reaction Medium in Gaining Access to Benzo[4,5]imidazo[1,2-a]pyrimidines under Microwave Heating.CHEMINFORM, Issue 49 2009Shu-Liang Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: A New Mild Base-Catalyzed Mannich Reaction of Hetero-Arylamines in Water: Highly Efficient Stereoselective Synthesis of ,-Aminoketones under Microwave Heating.CHEMINFORM, Issue 33 2009Wen-Juan Hao Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: 1,4-Cyclohexadiene with Pd/C as a Rapid, Safe Transfer Hydrogenation System with Microwave Heating.CHEMINFORM, Issue 4 2009John F. Quinn Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Acid-Mediated Three-Component aza-Diels,Alder Reactions of 2-Aminophenols under Controlled Microwave Heating for Synthesis of Highly Functionalized Tetrahydroquinolines.CHEMINFORM, Issue 9 2007Part 9. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] A New LiBr-Catalyzed, Facile and Efficient Method for the Synthesis of 14-Alkyl or Aryl-14H-dibenzo[a,j]xanthenes and Tetrahydrobenzo[b]pyrans under Solvent-Free Conventional and Microwave Heating.CHEMINFORM, Issue 49 2006Anil Saini Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Reduction of Aromatic Nitro Compounds Using Microwave Heating Assisted with Alumina-Supported Hydrazine/Fe(NO3)3×9H2O.CHEMINFORM, Issue 23 2006Chang-Rui Zhang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] A One-Pot Isomerization,Arylation of 2,3-Epoxycyclohexanone under Controlled Microwave Heating.CHEMINFORM, Issue 44 2005Andreas Svennebring Abstract For Abstract see ChemInform Abstract in Full Text. [source] An Improved Method for the Synthesis of 6-Substituted-5H-pyrrolo[2,3-b]pyrazines via Palladium-Catalyzed Heteroannulation Using Microwave Heating.CHEMINFORM, Issue 9 2005Corey R. Hopkins No abstract is available for this article. [source] Highly Regioselective Wittig Reactions of Cyclic Ketones with a Stabilized Phosphorus Ylide under Controlled Microwave Heating.CHEMINFORM, Issue 36 2004Jinlong Wu Abstract For Abstract see ChemInform Abstract in Full Text. [source] One Step Synthesis of Novel Antimicrobial 2-Hydroxy Diaryl Ethers Through Domestic Microwave Heating.CHEMINFORM, Issue 29 2004Sanjay Kumar Abstract For Abstract see ChemInform Abstract in Full Text. [source] Pd/C-Catalyzed Heck Reaction in Ionic Liquid Accelerated by Microwave Heating.CHEMINFORM, Issue 16 2004Xingang Xie Abstract For Abstract see ChemInform Abstract in Full Text. [source] Rhodium-Catalyzed Allylation of Aldehydes with Homoallylic Alcohols by Retroallylation and Isomerization to Saturated Ketones with Conventional or Microwave HeatingCHEMISTRY - AN ASIAN JOURNAL, Issue 1 2008Yuto Sumida Abstract The treatment of an aldehyde with a tertiary homoallylic alcohol at 100,250,°C in the presence of cesium carbonate and a rhodium catalyst leads to allyl transfer from the homoallylic alcohol to the aldehyde. The process includes Rh-mediated retroallylation to form an allyl rhodium species as the key intermediate. The homoallylic alcohol formed initially through allyl transfer is converted under the reaction conditions into the corresponding saturated ketone when bulky ligands are used. Microwave heating at 250,°C accelerates the reaction significantly. [source] Fast Transformation of Glucose and Di-/Polysaccharides into 5-Hydroxymethylfurfural by Microwave Heating in an Ionic Liquid/Catalyst SystemCHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 9 2010Dr. Xinhua Qi Abstract An efficient method for converting glucose into 5-hydroxymethylfurfural (5-HMF), in the presence of CrCl3 catalyst, is developed by using the ionic liquid 1-butyl-3-methyl imidazolium chloride as solvent. A 5-HMF yield of 71,% is achieved in 30,s for 96,% glucose conversion with microwave heating at 140,°C. The activation energy of glucose conversion is determined to be 114.6,kJ,mol,1, with a pre-exponential factor of 3.5×1014,min,1. Fructose, sucrose, cellobiose, and cellulose are studied and 5-HMF yields of 54,% are obtained for cellulose conversion at 150,°C during 10,min of reaction time. Recycling of the ionic liquid and CrCl3 is demonstrated with six cycles of use. [source] One-pot Synthesis of 10-Methyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione Derivatives under Microwave Heating without CatalystCHINESE JOURNAL OF CHEMISTRY, Issue 12 2005Guo-Ping Hua Abstract A series of 10-methyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione derivatives were synthesized by one-pot reaction of aldehyde, dimedone or 1,3-cyclohexanedione and methylamine in glycol or water under microwave heating without catalyst. The method has the advantage of short routine and reaction time, high yields as well as friendly environment. And the reaction was not only suitable for aliphatic and aromatic monoaldehyde, but also for aromatic dialdehyde. [source] Nucleation and Expansion During Extrusion and Microwave Heating of Cereal FoodsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 4 2003C.I. Moraru ABSTRACT Expansion of biopolymer matrices is the basis for the production of a wide variety of cereal foods. A limited number of manufacturing processes provide practical solutions for the development of an impressive variety of expanded products, just by changing process variables. It is therefore essential that the mechanisms involved in expansion are well known and controlled. This paper summarizes the knowledge of nucleation and expansion in extruded and microwaved products available to date. The effect of processing conditions and properties of the biopolymeric matrix on nucleation and expansion are discussed. Moisture content enables the glassy polymeric matrix to turn into rubbery state at process temperatures, which allows superheated steam bubbles to form at nuclei and then expand, expansion being governed by the biaxial extensional viscosity of the matrix. Nucleation and expansion theories are presented along with quantitative data that support them. [source] Microwave Assisted Synthesis of Yb:Y2O3 Based Materials for Laser Source Application,ADVANCED ENGINEERING MATERIALS, Issue 3 2010Anna Luisa Costa Yb:Y2O3 submicrometric particles were synthesized through co-precipitation of Yb and Y nitrate in water. Microwave heating and controlled release of ammonia through urea decomposition at reaction temperature leaded to the formation of disaggregated, monosized spherical particles of carbo-hydroxy-nitrate precursors. Pure crystalline Yb:Y2O3 powder that preserved the described morphology was obtained after calcination in air at 800,°C for 30,min. This powder mixed with commercial alumina powder was used to produce transparent Yb:YAG ceramics. Improved properties in terms of powder morphology and reactivity were presented in comparison with powders obtained by traditional heating. [source] Numerical analysis of microwave heating of a dielectricHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2003Yuichi Funawatashi Abstract Microwave heating of a dielectric in a cavity was analyzed numerically with the FDTD method with the aim of devising new methods for reducing uneven heating typical of microwaving. The dielectric was assumed to be water and the frequency of a microwave was taken to be 1 GHz. It was found that the electric field is highly dependent on the position of the dielectric in a cavity. The temperature distribution reflects the profile of the RMS value of the electric field in the dielectric, although there appears to be no effect of the short wavelength typical of the electric field. The heating rate depends on the position of the dielectric. In the case of a higher effective loss factor a microwave decays immediately after entering the dielectric, and the temperature of the interior remains low. These results indicate that the uneven heating is due to at least two causes: standing wave and rapid decay of a microwave. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(3): 227,236, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.10087 [source] Microwave and convective dehydration of ethanol treated and frozen apple , physical properties and drying kineticsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2002Tomas Funebo The objective of this study was to examine how the drying kinetics and physical properties of apples are affected by pre-treatment with 95% ethanol or freezing at ,18 °C before microwave-assisted air dehydration at 50, 60 and 70 °C. Microwave heating was used to obtain these temperatures in the centre of the apple cubes. After dehydration the shrinkage and rehydration capacity were measured. The texture of dehydrated and rehydrated samples was analysed with a puncture test in a texture analyser. Samples were also analysed with confocal laser scanning microscopy to determine the correlation between physical and microstructural properties. Diffusivity in the different dehydration processes was calculated. Ethanol-treated apples showed both high rehydration and high effective rehydration capacity compared with the other samples. Freezing before dehydration increased the diffusivity and reduced the firmness of rehydrated apples compared with no pre-treatment. [source] Removal of heavy metals from municipal solid waste incineration (MSWI) fly ash by traditional and microwave acid extractionJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2010Jun Xue Abstract BACKGROUND: Municipal solid waste incinerator (MSWI) fly ash is regarded as hazardous waste because it contains various toxic metals. A previous study has shown that fly ash can be detoxified by removal of heavy metals. In this work, the extractability of heavy metals from MSWI fly ash by traditional and microwave acid extraction were compared. RESULTS: A 24 , 1 fractional factorial experimental design was adopted using acid concentration, extraction time, temperature, and liquid/solid (L/S) ratio as the experimental factors for traditional extraction, and acid concentration, extraction time, liquid/solid (L/S) ratio and microwave power as the experimental factors for microwave extraction. The traditional extraction results show that L/S played an important role in Zn, Cd extraction while L/S ratio and extractant concentration were important for Pb extraction. However, no controlling parameter was determined for Cu and Cr extraction. For the microwave extraction, it was shown that L/S was important for Pb and Zn and extractant concentration was important for Pb, Zn and Cd. The time and the power were not significant for the extractability of heavy metals. CONCLUSION: Hydrochloric acid was an effective extractant. Microwave heating promoted extraction and shortened extraction time. Microwave acid extraction treatment is a potentially feasible method for the removal of heavy metals from MSWI fly ash. Copyright © 2010 Society of Chemical Industry [source] Microwave-assisted ring-opening polymerization of p -dioxanoneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2008Yu-Yan Chen Abstract The ring-opening polymerization (ROP) of p -dioxanone (PDO) under microwave irradiation with triethylaluminum (AlEt3) or tin powder as catalyst was investigated. When the ROP of PDO was catalyzed by AlEt3, the viscosity-average molecular weight (Mv) of poly(p -dioxanone) (PPDO) reached 317,000 g mol,1 only in 30 min, and the yield of PPDO achieved 96.0% at 80 °C. Tin powder was successfully used as catalyst for synthesizing PPDO by microwave heating, and PPDO with Mv of 106,000 g mol,1 was obtained at 100 °C in 210 min. Microwave heating accelerated the ROP of PDO catalyzed by AlEt3 or tin powder, compared with the conventional heating method. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3207,3213, 2008 [source] Effects of processing and storage on walnut (Juglans regia L) tannins,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2001Kar Wai Clara Sze-Tao Abstract Walnut tannins were maximally extracted with absolute methanol and an extraction time of 60,min. Storage (21 days at 25,°C) significantly reduced (20,40% reduction) the assayable tannin content in walnuts. The ranges of tannin content in freshly cracked inshell and shelled walnuts were respectively 372,1095 and 363,667,mg catechin equivalent per 100,g dry weight. The assayable tannin content in inshell and shelled walnuts was 10,20% higher when the particle size was reduced from 2- to 8-mesh. Using 0.5 as compared to 2% (w/v) vanillin as colour development reagent yielded 15,20% higher assayable tannin contents. The assay colour development reached a maximum after 20,min of incubation at 25,°C. Roasting (204,°C for 5,min) caused a small (14%) but significant reduction in assayable tannins. Soaking in aqueous alkali solutions was more effective (44,100% reduction) than soaking in aqueous acid solutions (6,76% reduction) in decreasing the assayable tannin content in walnuts. Microwave heating in distilled deionised water resulted in 93,98% reduction in walnut assayable tannins. Blanching at 100,°C for 2,min was as effective as alkali soaking in significantly reducing the amount of extractable walnut tannins (98% reduction). The tannin content in blanched walnuts was positively related to astringency scores (r,,=,0.92). © 2001 Society of Chemical Industry [source] | |||||||||||||||||||||||||||||||