Variation of Ultrasonic Parameters with Fat Crystallization

MARTINI, HERRERA, MARANGONI

University of Guelph, ON, Canada

Congreso; Canadian Institute of Food Science and Technology and Agriculture and Agri-Food Canada Joint Conference (CIFST/AAFC); 2004

Canadian Institute of Food Science and Technology and Agriculture

Different fat systems were crystallized from 60 to 25, 30 and 35 °C at a cooling rate of 8 °C/min while being sheared at 400 rpm. Differences in composition and melting points of the fats resulted in characteristic crystallization behavior.The crystallization process was measured using ultrasonics and the solid fat content (SFC) was measured using pulsed NMR. Transducers of 550 KHz frequency and 650 KHz bandwidth were used to carry out the experiments. The Integrated Response (IR), Time of Flight (TF) and the Full Width Half Maximum (FWHM) parameters were measured as a function of time together with the cell temperature variation as cooling took place. The results showed that the TF of the ultrasonic waves decreased as the fat crystallized (increase in SFC). A linear correlation was found between TF (R2 = 0.97) and SFC up to 16%. IR diminished as SFC increased while the FWHM increased. No clear trends were found between IR and FWHM with SFC.