Ultrasonic inactivation of microorganisms #46

Abstract

High-power ultrasound has a great potential to become a nonthermal method for food preservation and shelf-life extension without affecting the quality and organoleptic properties of food products. While it is not yet used in the food industry, it is an established, robust, flexible, and well-studied technology. In this chapter we review the current knowledge on the effect of high-power ultrasound, both low and high frequency, on the inactivation of microorganisms in aqueous solutions and model food systems. The main aim of the chapter is to relate the important parameters of ultrasonication and the properties of the microorganisms in order to obtain a fundamental understanding. For instance, the importance of the bacteria capsule is found to an important property for the resistance of bacteria to ultrasound. Similarly, the bacteria size and shape are important parameters, which might influence the inactivation of bacteria, depending on their state of growth (e.g., log phase vs stationary phase). Combination of hurdle technologies involving high-power ultrasound, such as manosonication, could offer further advantage in the use of nonthermal technologies for food preservation.