Browsing by Author "Koch, Tim"

Ultrasound velocity and attenuation of soft tissues have been widely investigated. However, few studies completely covered considerable variations of both, structure and composition. The aim of this study was to collect acoustic reference data of porcine Longissimus muscle and associate them with compositional traits. In addition, measurements were conducted on fresh, formalin fixed, and frozen-thawed samples to evaluate the effect of processing on ultrasound parameters and comparisons with earlier investigations. Measurement conditions (temperature and fibre orientation) were realised close to hanging carcasses conditions. Sound velocity ranged from 1617 +/- 6 to 1622 +/- 5 ms(-1), while attenuation mostly ranged from 1.0 +/- 03 to 1.2 +/- 0.3 dB MHz(-1) cm(-1). Only formalin fixed samples showed significantly higher attenuation (2.2 +/- 0.6 dB MHz(-1) cm(-1)). Highest correlations have been observed between intramuscular fat and attenuation (up to r = .7). The obtained results are anticipated to improve ultrasound based estimation of the intramuscular fat of pig muscle on intact carcasses. (C) 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

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.