Non-thermal, energy efficient hydrodynamic cavitation for food processing, process intensification and extraction of natural bioactives: A review

Hydrodynamic cavitation (HC) is the process of bubbles formation, expansion, and violent collapse, which results in the generation of high pressures in the order of 100–5000 bar and temperatures in the range of 727–9727 °C for just a fraction of seconds. Increasing consumer demand for high-quality foods with higher nutritive values and fresh-like sensory attributes, food processors, scientists, and process engineers are pushed to develop innovative and effective non-thermal methods as an alternative to conventional heat treatments. Hydrodynamic cavitation can play a significant role in non-thermal food processing as it has the potential to destroy microbes and reduce enzyme activity while retaining essential nutritional and physicochemical properties. As hydrodynamic cavitation occurs in a flowing liquid, there is a decrease in local pressure followed by its recovery; hence it can be used for liquid foods. It can also be used to create stable emulsions and homogenize food constituents. Moreover, this technology can extract food constituents such as polyphenols, essential oils, pigments, etc., via biomass pretreatment, cell disruption for selective enzyme release, waste valorization, and beer brewing. Other applications related to food production include water treatment, biodiesel, and biogas production. The present review discusses the application of HC in the preservation, processing, and quality improvement of food and other related applications. The reviewed examples in this paper demonstrate the potential of hydrodynamic cavitation with further expansion toward the scaling up, which looks at commercialization as a driving force.