scholarly journals Effect of Vertical and Horizontal Sample Orientations on Uniformity of Microwave Heating Produced by Magnetron and Solid-State Generators

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1986
Author(s):  
Somayeh Taghian Dinani ◽  
Alina Jenn ◽  
Ulrich Kulozik
Keyword(s):  
Solid State ◽  
Microwave Heating ◽  
Food Packaging ◽  
Heat Processing ◽  
Vertical Position ◽  
Color Changes ◽  
Horizontal Orientation ◽  
Microwave System ◽  
Absorbed Power ◽  
Microwave Heat

In this study, the effect of different horizontal and vertical orientations of a model sample (cuboid gellan gel samples containing Maillard reactants) on microwave heat processing was investigated in the solid-state and magnetron microwave systems. To achieve this target, seven orientations inside both microwave cavities were defined. Two of the investigated sample orientations were in a vertical position with and without turntable rotation, and five in a horizontal position. Furthermore, samples at horizontal orientations were put at an angle position without turntable rotation. To analyze the microwave heating patterns, infrared (IR) pictures and photographs of the gellan gel samples were taken after processing to document IR-based thermal and Maillard color changes, respectively. Three main factors for improvement of the heating homogeneity were identified: first, processing samples in the solid-state microwave system; second, position variation of the sample by turntable activated; and third, horizontal orientation. In addition, it was observed that placing the gellan gel samples in a vertical position in the magnetron microwave system resulted in considerably more absorbed power and a more uniform microwave heat processing compared to other horizontal orientations in this system. This indicated a non-uniform microwave field distribution. The results of this study can also confirm the importance of designing suitable food packaging: a vertical shape for more microwave energy absorbance and thus, more energy efficiency, and a horizontal shape for more uniform microwave heat processing.

scholarly journals Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2569
Author(s):  
Mia Kurek ◽  
Nasreddine Benbettaieb ◽  
Mario Ščetar ◽  
Eliot Chaudy ◽  
Maja Repajić ◽  
...  
Keyword(s):  
Food Packaging ◽  
Water Solubility ◽  
Color Change ◽  
Chitosan Film ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Color Changes ◽  
Insoluble Particles ◽  
Polymer Stability ◽  
Food Packaging Films

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.

Microwave-assisted solid-state synthesis of NaRE(MO4)2 phosphors (RE = La, Pr, Eu, Dy; M = Mo, W)

2020 ◽  
Vol 49 (23) ◽  
pp. 7914-7919 ◽  
Author(s):  
S. Sameera Perera ◽  
Hashini N. Munasinghe ◽  
Emily N. Yatooma ◽  
Federico A. Rabuffetti
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Metal Ions ◽  
Microwave Heating ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Double Molybdate ◽  
Microwave Assisted ◽  
Double Tungstate ◽  
Phase Pure

Microwave heating provides rapid access to crystalline and phase pure double molybdate and double tungstate phosphors activated by rare-earth metal ions.

Synthesis and Microstructural Control of In2O3(ZnO)3 Layered Compound by Microwave-Heating

2009 ◽  
Vol 620-622 ◽  
pp. 85-88 ◽  
Author(s):  
Shouhei Yanagiya ◽  
Yamato Hayashi ◽  
Hirotsugu Takizawa
Keyword(s):  
Solid State ◽  
Microwave Heating ◽  
Band Gap Energy ◽  
Layered Compound ◽  
Bottom Part ◽  
Heated Sample ◽  
Powder Bed ◽  
Silica Substrate ◽  
State Diffusion ◽  
Plane Direction

In2O3(ZnO)3 layered compound was synthesized by 2.45 GHz microwave heating in a solid state reaction. Microwave-processed samples were obtained at low temperature by the enhancement of solid state diffusion and sublimation of the powder bed. Plate-like grain microstructures formed on the bottom part of the pellet, and vicinity of the surface was dense. The plate-like grain was oriented in the ab-plane direction. Compared with a conventional heated sample, the electrical conductivity increased and the band gap energy decreased. In the case of deposition on a silica substrate by microwave heating, the plate-like grain film was synthesized.

scholarly journals Glycation of Ovalbumin in Solid-State by Conductive and Microwave Heating

2009 ◽  
Vol 15 (4) ◽  
pp. 377-380 ◽  
Author(s):  
Yasuhiro TSUBOKURA ◽  
Shunji FUKUZAKI ◽  
Seiji NOMA ◽  
Noriyuki IGURA ◽  
Mitsuya SHIMODA
Keyword(s):  
Solid State ◽  
Microwave Heating

High molecular weight bio furan-based co-polyesters for food packaging applications: synthesis, characterization and solid-state polymerization

2016 ◽  
Vol 18 (19) ◽  
pp. 5142-5150 ◽  
Author(s):  
Sungmin Hong ◽  
Kyung-Deok Min ◽  
Byeong-Uk Nam ◽  
O Ok Park
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
High Molecular Weight ◽  
Food Packaging ◽  
Melt Polycondensation ◽  
Solid State Polymerization

High molecular weight bio furan-based copolyesters have been synthesized by melt polycondensation and solid-state polymerization for packaging applications as bio based alternatives to PET.

scholarly journals A new concept to improve microwave heating uniformity through data-driven process modelling

2019 ◽  
Author(s):  
Yingguang Li ◽  
Jing Zhou ◽  
Di Li
Keyword(s):  
Microwave Heating ◽  
Process Model ◽  
Influence Factor ◽  
Data Driven ◽  
Experimental Investigations ◽  
Microwave System ◽  
Long Time ◽  
Heating Uniformity ◽  
Heating Pattern

For a long time, the heating pattern of the workpiece within a multimode microwave oven was considered to be highly sophisticated. As a consequence, the uneven microwave heating problem can only be partly alleviated by a random movement between the electromagnetic field and the workpiece. In this paper, we reported that the heating pattern has a specific correspondence with microwave system settings. The influence factor of the heating pattern and the corresponding mechanism were systematically studied by both theoretical analysis and experimental investigations. On this basis, a data-driven process model was established to learn the material’s dynamic temperature behaviors under different microwave system settings, and a new concept to improve the microwave heating uniformity by temperature monitoring and active compensation was proposed. The effectiveness of the method was demonstrated by a polymer composite microwave processing case study.

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