Energy issues in microwave food processing: A review of developments and the enabling potentials of solid-state power delivery

Abstract

The enormous magnitude and variety of microwave applications in household, commercial and industrial food processing creates a strong motivation for improving the energy efficiency and hence, sustainability of the process. This review critically assesses key energy issues associated with microwave food processing, focusing on previous energy performance studies, energy performance metrics, standards and regulations. Factors affecting energy-efficiency are categorised into source, load and source-load matching factors. This highlights the need for highly-flexible and controllable power sources capable of receiving real-time feedback on load properties, and effecting rapid control actions to minimise reflections, heating non-uniformities and other imperfections that lead to energy losses. A case is made for the use of solid-state amplifiers as alternatives to conventional power sources, magnetrons. By a full-scale techno-economic analysis, including energy aspects, it is shown that the use of solid-state amplifiers as replacements to magnetrons is promising, not only from an energy and overall technical perspective, but also in terms of economics.

High‐pressure processing, microwave, ohmic, and conventional thermal pasteurization: Quality aspects and energy economics

“…In translating to production‐type scenarios, it is important to note that specific energies are sensitive to equipment design and operating conditions. Atuonwu and Tassou (, ) using a theoretical model show that HPP energy performance improves with scale and vessel fill ratio. Current industrial HPP systems operate usually in batch mode, which increases labor costs.…”

“…Comprehensive reviews of previous work in these areas include Ortega‐Rivas and Salmeron‐Ochoa (), Gabrić et al (), Jiménez‐Sánchez, Lozano‐Sánchez, Segura‐Carretero, and Fernández‐Gutiérrez (), Barba, Koubaa, Prado‐Silva, Orlien, and de Souza Sant'Ana (), and Bevilacqua et al () studies. Other studies have focused primarily on energy and sustainability issues (Aganovic et al, ; Atuonwu et al, ; Atuonwu & Tassou, , ; Rodriguez‐Gonzalez, Buckow, Koutchama, & Balasubramamian, ). Atuonwu et al () compared the energy consumption per liter of orange juice by microwave, ohmic, HPP, and conventional thermal processes as well as the associated greenhouse gas (GHG) emissions.…”

Microwave-Induced In Situ Amorphization: A New Strategy for Tackling the Stability Issue of Amorphous Solid Dispersions

“…Microwaves are electromagnetic waves with high frequencies (0.3-300 GHz) and wavelengths in the cm range, i.e., 1-0.001 m, which have been widely used in the fields of communication, radar, industry, scientific research, medicine and domestic life [52]. Microwave heating systems are usually restricted within the industrial, scientific and medical (ISM) frequency bands, using certain license-free frequencies designated by the International Telecommunication Unit (ITU) with international agreements [53]. Among them, the most commonly used frequency for commercial and domestic uses in most countries is 2.45 GHz with a wavelength of 0.122 m and a penetration depth of 0.014 m in water at 25 • C [54,55].…”

Effects of microwave heating on quality attributes of pineapple juice

“…Microwave oven operates usually at relatively high frequencies ranged from the frequency of 300 MHz–300 GHz (Fu, Chen, Huang, & Luo, 2017) and the power of <100–1000 W (Atuonwu & Tassou, 2019). The microwave energy may possibly affect food quality due to heat generated within food material.…”