Non-Destructive Detection of Air Traces Inside UHT Milk Package by Using Ultrasonic Through Transmission Method

Abstract

In this work, we have exploited the ultrasonic through transmission technique to assess the quality of UHT milk within its package in a non-destructive manner. This control is based on the monitoring of the evolution of ultrasonic parameters, namely the peak to peak amplitude, flight time, velocity and attenuation in different temperatures of incubation. To check the reliability of this technique, we compared the evolution of these parameters in the following both special cases: package of sterilized UHT milk (without air infiltration) and package of unsterilized UHT milk (with air infiltration). By analyzing the results from this experimental study, we demonstrated the ability of this method to detect the presence of air traces inside the package. This is confirmed by the detection of a particular time where the separation starts between the sterilized and unsterilized traces for each ultrasonic parameter. Furthermore, this study showed that 35°C is the most suitable temperature for bacterial growth in UHT milk because in this one where we found an early contamination of UHT milk in comparison with other temperatures. We also found that the flight time is the most sensitive ultrasonic parameter for microbial contamination compared with other studied ultrasonic parameters.