Document Type



Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence


Agricultural biotechnology and food biotechnology

Publication Details

Food Control

Volume 34, Issue 2, December 2013, Pages 364-371


In recent years, there has been considerable interest in non-thermal milk processing. The objective of the present study was to assess the efficacy of two non-thermal technologies (manothermosonication; MTS, and pulsed electric fields; PEF) in comparison to thermal pasteurisation, by assessing the microbial levels of each of these milk samples post-processing. Homogenised milk was subjected to MTS (frequency; 20 kHz, amplitude; 27.9 μm, pressure; 225 kPa) at two temperatures (37 °C or 55 °C), before being immediately treated with PEF (electric field strength; 32 kV/cm, pulse width; 10 μs, frequency; 320 Hz). Thermal pasteurisation (72 °C, 20 s) was included as a control treatment. Microbial content of each milk sample was monitored over a 21-day period. It was determined that milks treated with MTS/PEF at 37 °C and 55 °C contained lower microbial levels than raw milk for a certain duration, but after 14 days milk which had been pasteurised by conventional methods contained significantly (P < 0.05) less microorganisms. However, milks treated with MTS/PEF contained significantly (P < 0.05) fewer microorganisms than raw milk at each time point. Although not as effective as pasteurisation, the present study demonstrates the ability of MTS/PEF treatment to reduce microbial content of milk, while avoiding prolonged heat exposure to temperatures such as those used during conventional (thermal) pasteurisation.