Pulsed Electric Fields and Ultrasound for Enhanced Mass Transfer: A Review of Extraction and Drying in Food Processing

Abstract

Mass transfer operations, such as extraction and drying, are often associated with high energy consumption, extensive use of solvents, and long processing times. Advanced cell permeabilization technologies, such as pulsed electric field (PEF) and high-intensity ultrasound (HIUS), are known for enhancing these processes through mass transfer intensification. Furthermore, the combined application of these techniques has recently been explored due to the synergy between their effects, which allows for improved yields and energy savings in processing. This review presents the combination of PEF and HIUS technologies as an alternative to improve industrial solid–liquid extractions and drying operations for food and byproducts. The fundamentals of each technology, the physical phenomena behind electroporation and acoustic cavitation, and how these mechanisms enhance mass transfer are discussed. Additionally, recent research advancements involving the combined method are summarized and compared to conventional methods or the isolated application of each technology. In general, the application of PEF as a pretreatment, followed by HIUS-assisted processes, shows great potential for synergistically improving mass transfer operations. The combined method resulted in a higher recovery of bioactive compounds, such as polyphenols and other antioxidants. Moreover, this technology combination significantly reduced drying time, leading to energy savings while maintaining the visual appearance and nutritional quality of the dried products. The synergy between the two techniques is attributed to the additional alteration of the cell microstructure, further reducing mass transfer resistance. However, determining optimal treatment parameters is crucial to maximize benefits and avoid potential negative effects associated with these innovative technologies.