A computational study to design process conditions in industrial radio-frequency tempering/thawing process

Conventional thawing processes adopted by food industry are characterized by longer operation times and food quality losses. Recently, batch and continuous radio-frequency (RF) assisted thawing were proposed as alternative and faster process, but their economic feasibility at industrial level is far to be assessed. Undoubtedly, longer penetration depth and ability to generate volumetric heat enable RF assisted heating a very promising technology to apply at industrial scale. On the other hand, most of the RF systems in operation are built following heuristic criteria, more than being designed and tailored on specific products or processes: this has limited the development of RF based system for food thawing as well as the proposal of simple but effective control systems. The literature has contributed with a number of theoretical and modeling based works for RF processes, but design-based studies in general are limited. Therefore, the objective of this study was to present a strategy for virtual design of a continuous RF thawing process. For this purpose, a previously developed and experimentally validated mathematical model was modified to take into account the movement of food product through a continuous RF system, the movement of RF electrode and subsequent effects of temperature and electric field changes. Power uniformity index (PUI) for various proposed configurations was analyzed, and possible scenarios were suggested for an industrial scale process. With this concept, this study was assumed to be significant for design and optimization of industrial RF and RF thawing processes. (C) 2017 Elsevier Ltd. All rights reserved.