Ultrasonic assessment of the melting behaviour in fat from Iberian dry-cured hams

The feasibility of using ultrasounds to characterize the melting properties of fat from Iberian dry-cured hams was evaluated. Differential Scanning Calorimetry (DSC) and ultrasonic measurements were used to characterize the fat melting. The ultrasonic velocity in fat decreased with the increase in temperature, showing four different sections (0-4 degrees C, 4-10 degrees C, 10-20 degrees C and 20-24 degrees C). Ultrasonic velocity was related (R(2)=0.99) to the percentage of melted fat (%MEF) showing an increase of 5.4 ms(-1) for 1% increase of melted fat (%MEF above 60%). The thermal history did not affect the ultrasonic measurements from 10 to 25 degrees C and, consequently, this range was the most suitable for classifying Iberian dry-cured products with different genetics and feeding backgrounds. Ultrasonic measurements could be a reliable technique to estimate the %MEF and subsequently the related sensory attributes in Iberian dry-cured ham at 10-25 degrees C, which is the common temperature range for the consumption of Iberian dry-cured products.