Yazar "Marra, Francesco" seçeneğine göre listele

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  • Küçük Resim
    Öğe
    A comprehensive mathematical modeling study for temperature evolution during radio frequency assisted honey decrystallization
    (Institution of Chemical Engineers, 2025) Karataş, Ozan; Uyar, Rahmi; Son, Ezgi; Coşkun, Eda; Mert, Behiç; Marra, Francesco; Erdoğdu, Ferruh
    In industrial settings, honey decrystallization is conducted by conventional thermal processing with hot water (12–18 h) or air (24–36 h) at around 60 °C. Considering the demands for a green and sustainable efficient process, a novel approach is needed. Radio frequency (RF) heating is a dielectric process where volumetric heat generation within the sample is expected. Designing such a process requires the knowledge of temperature evolution within the product. Hence, the objective of this study was to develop a mathematical model to determine the temperature evolution of crystallized honey during RF processing and compare the results with conventional approach to demonstrate the efficiency. For this purpose, a computational model was developed to determine the temperature evolution in a crystallized honey during RF and conventional hot water processing. Natural convection effects were also included within the model to see whether there will be any improving effect despite the higher viscosity. Decrystallization kinetics was also coupled with temperature evolution to observe the process efficiency. The results indicated the efficiency of RF heating as an innovative processing approach for decrystallization while the natural convection effects were not significant.
  • Küçük Resim
    Öğe
    Honey De-crystallization by radio frequency heating for process efficiency: Computational monitoring combined with time domain nuclear magnetic resonance
    (Elsevier Ltd, 2023) Karataş, Ozan; Uyar, Rahmi; Berk, Berkay; Öztop, H. Mecit; Marra, Francesco; Erdoğdu, Ferruh
    Industrial de-crystallization of honey is carried out by using hot water or air at 60 °C or higher temperatures with the cost of energy and longer process times. The objectives of this study were to apply RF processing for de-crystallization and monitor this process with time-domain nuclear magnetic resonance (TD-NMR) data and a computational model. For this purpose, crystallized honey samples were processed in a 10 kW - 27.12 MHz free-running oscillator RF system, and experimental temperature data were used to validate the developed computational model. TD-NMR experiments were performed to monitor the de-crystallization, and the obtained kinetics data were coupled with temperature increase to compute the crystal content changes through the process. The RF de-crystallization led to a significant decrease (>70% compared to the conventional processes) in process time for industrial scale processing demonstrating its sustainability.