Eight-channel ultrasonic device for non-invasive quality evaluation in packed milk.
An eight-channel ultrasonic detecting device for microbiological quality evaluation of packed liquid foods is presented in this paper. This device makes possible a non-invasive detection of the microbial growth in liquid foods with no need to open the carton-based packages where they are contained. Thermal and humidity stabilization are required inside the measuring chamber. The changes in the liquid media produced by the microorganism growth induce variations in the ultrasonic propagation parameters giving a non-invasive evidence of the developing contamination. For that purpose, the amplitude and time of flight of an ultrasonic 800kHz tone burst travelling through an UHT milk pack are analysed. Inoculated and sterile packs were tested to evaluate the performance of this new non-invasive ultrasonic microbiological quality sensor.
Elvira
L
L
Instituto de Acústica, CSIC. Serrano 144, Madrid, Spain. lelvira@ia.cetef.csic.es <lelvira@ia.cetef.csic.es>
Sampedro
L
L
Montero de Espinosa
F
F
Matesanz
J
J
Gómez-Ullate
Y
Y
Resa
P
P
Echevarría
F J
FJ
Iglesias
J R
JR
D000818:Animals; D015169:Colony Count, Microbial / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D008892:Milk / Q000382:microbiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014159:Transducers