The Use of Ultrasound and Combined Technologies in Food Preservation

Abstract

TurkeyUltrasound techniques find use in the food industry in both the analysis and modification of foods. Microbial and enzyme inactivation are other applications of ultrasound in food processing. The use of ultrasound on its own in the food industry for bacterial destruction is currently unfeasible; however, the combination of ultrasound and pressure and/or heat shows considerable promise. The future of ultrasound in the food industry for bactericidal purposes lie in thermosonication, manosonication, and manothermosonication, as they are more energy-efficient and result in the reduction of microbial and enzyme activity when compared to conventional heat treatment. The use of ultrasound and combined technologies, mechanisms, and effects of ultrasound combinations are discussed in this review.

Effect of ultrasound power on physicochemical and rheological properties of yoghurt drink produced with thermosonicated milk

“…Ultrasonication itself generates considerable amount of heat in a liquid matrix (Demirdoven & Baysal, 2009;Riener et al, 2009), and the control of this heat is significant in determining the individual effect of ultrasonication on the physical and functional properties of liquid foods like milk. In a study by Nguyen and Anema (2010), the effect of ultrasound on the properties of skim milk used in the formation of acid gels was distinguished from the heat-related effects of ultrasonication.…”

Effect of ultrasonication on the properties of skim milk used in the formation of acid gels

“…During a low pressure cycle, vacuum bubbles can be formed and these bubbles expand, contract and violently collapse (cavitation) during the pressure cycles. The collapse of the bubbles results in rapid and marked increases in local temperature and pressure, causing strong currents and turbulence, which ultimately results in violent collisions between particles, and very high shear forces (Raso & Barbosa-Canovas, 2003;Morris, Brody & Wicker, 2007;Demirdoven & Baysal, 2009). Although US is considered to be a non-thermal technique, considerable heat is generated during its application, and this heat must be considered or controlled during the US treatment (Demirdoven & Baysal, 2009).…”

Effectiveness of combined Pulsed Electric Field (PEF) and Manothermosonication (MTS) for the control of Listeria innocua in a smoothie type beverage

“…When ultrasound, at high power and low frequency (20e100 kHz) propagates in liquid media, resulting in longitudinal waves, cavitation is induced, which consists of the formation, growth and sudden implosion of bubbles. The implosion of bubbles generates localised spots with very high pressures (104e105 kPa) and temperature (5500 C) that can disrupt cellular structures (Demirdoven & Baysal, 2009).…”