Ultrasound velocity and attenuation of porcine soft tissues with respect to structure and composition: II. Skin and backfat

Ultrasound is regarded as a promising method to determine the intramuscular fat content of pork loin. At intact carcasses, the signal passes the backfat whose ultrasound parameters (sound velocity and attenuation) have not been fully investigated. This study intended to collect a dataset of ultrasound parameters for individual backfat layers and to elucidate relationships with structural and compositional characteristics. In-vitro measurements at 10 MHz were conducted on backfat samples of pork carcasses representative for German populations. The average sound velocity ranged from 1436 +/- 9 to 1470 +/- 37 ms(-1) for the fat layers, and 1682 +/- 23 ms(-1) for skin. Velocity of the compound backfat decreased with overall thickness. Attenuation was not affected by thickness ranging between 1.6 +/- 0.7 and 2.7 +/- 1.5 dB MHz(-1) cm(-1) for all layers. Sound velocity was negatively correlated with fat content and dry matter. The obtained results are anticipated to improve signal correction prior to spectral analysis of ultrasound measurements at intact carcasses. (C) 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.