Non-Thermal Technologies in Food Processing: Implications for Food Quality and Rheology

The food industry mostly utilises thermal processing technologies to enhance the food safety and shelf life by inactivating enzymes, pathogens, and spores. However, there is a shift towards consumer preference for minimally processed foods due to health concerns and the limitations of the conventional thermal processing methods. Thus, the food industry has recently increased the utilisation of non-thermal technologies for food processing and preservation in the production of foods while maintaining the nutritional and sensory qualities of the food. Non-thermal approaches including a Pulsed Electric Field (PEF), High-Pressure Processing (HPP), Ionising Radiation (IOR), Ultraviolet (UV) light, Pulsed Light (PL), and Cold plasma (CP) are increasingly being employed for food preservation, especially for heat-sensitive foods, as they enable microbial inactivation with minimal or no thermal application and less degradation of bioactive constituents of foods. As opposed to conventional thermal technologies that may compromise the food quality, non-thermal preservation processes retain the texture, taste, and rheological properties, therefore presenting an invaluable option in the food chain system. Moreover, non-thermal food processing approaches are becoming well-established within the food sector as they can be utilised for a wide range of food items. This paper provides a critical review of the industrial applications, mechanisms of action, and efficiency of major non-thermal food processing technologies. In addition, it also addresses their impact on the food quality, microstructure, and rheology, while exploring their limitations. Although these technologies are of great value in preserving the shelf life and food integrity, high upfront investment costs continue to discourage large-scale adoption. However, with the growing demand for fresh and minimally processed foods, the operational costs for these technologies are expected to become more accessible, promoting their widespread adoption in the industry.