Computer simulation model development and validation of radio frequency heating for bulk chestnuts based on single particle approach

Upscaling via a Prospective LCA: A Case Study on Tomato Homogenate Using a Near-to-Market Pasteurisation Technology

Thanks to food technology, the production of cold tomato soups such as salmorejo, a traditional Spanish dish, has become industrialised. Thermal treatments play an important role in ready-to-eat meals, prolonging their shelf-life. Radiofrequency (RF) heating is less energy-intensive than conventional heat exchangers and has been successfully used to pasteurise food; novel applications, however, provide results at laboratory or pilot scale, so conclusions might not be translatable to industry. In this study, a prospective Life-Cycle Assessment of salmorejo pasteurised using RF was performed to highlight the relevance of upscaling and to compare its environmental impacts with those of conventional pasteurisation. “Gate-to-gate” results show that the pilot has greater environmental impacts due to its greater energy consumption, as thermal energy is not recovered. The packing and landfill of organic waste exhibit the highest impacts at industrial scale. RF technology does not imply significant environmental improvements versus conventional pasteurisation. Potential changes in the energy background of future scenarios have relevant consequences in the environmental impacts. “Farm-to-factory-gate” analysis highlights ingredients and tomato valorisation as the most impacting stages. The prospective LCA of scaled up scenarios constitutes a tool for environmental screening in food ecodesign, contributing to Sustainable Development Goal 12.

Recent developments in radio frequency drying for food and agricultural products using a multi-stage strategy: a review

Radio frequency (RF) drying is an emerging technology for food and agricultural products, holding features of rapid, uniform, stable, and volumetric heating, high energy efficiency, and moisture leveling. However, the RF drying with a single stage commonly has drawbacks of unexpected product quality, non-uniform moisture distribution, and prolonged drying time. The multi-stage drying approach could overcome the shortcomings of one-stage strategy accordingly by applying different drying methods or operating parameter values in each phase separately. This review describes the principle of RF heating, presents the typical systems and superiorities of RF drying, and provides a comprehensive overview on recent development in applications of both the one-stage and the multi-stage RF drying, and analysis of drying characteristics and merits for different types of the two-stage strategy. This review finally proposes recommendations for future studies in improving and optimizing the existing RF drying protocols and scaling up them to industrial applications.

A comprehensive review on recent developments of radio frequency treatment for pasteurizing agricultural products

Recent pathogen incidents have forced food industry to seek for alternative processes in postharvest pasteurization of agricultural commodities. Radio frequency (RF) heating has been used as one alternative treatment to replace chemical fumigation and other conventional thermal methods since it is relatively easy to apply and leaves no chemical residues. RF technology transfers electromagnetic energy into large bulk volume of the products to provide a fast and volumetric heating. There are two types of RF technology commonly applied in lab and industry to generate the heat energy: free running oscillator and 50-Ω systems. Several reviews have been published to introduce the application of RF heating in food processing. However, few reviews have a comprehensive summary of RF treatment for pasteurizing agricultural products. The objective of this review was to introduce the developments in the RF pasteurization of agricultural commodities and to present future directions of the RF heating applications. While the recent developments in the RF pasteurization were presented, thermal death kinetics of targeted pathogens as influenced by water activity, pathogen species and heating rates, non-thermal effects of RF heating, combining RF heating with other technologies for pasteurization, RF heating uniformity improvements using computer simulation and development of practical RF pasteurization processes were also focused. This review is expected to provide a comprehensive understanding of RF pasteurization for agricultural products and promote the industrial-scale applications of RF technology with possible process protocol optimization purposes.