Journal of Muscle Foods (Impact Factor: 0.5). 05/2007; 13(1):1 - 12. DOI: 10.1111/j.1745-4573.2002.tb00316.x

ABSTRACT ABSTRACTA shear mapping method (SMM) was developed and evaluated for examining objectively the effectiveness of tenderization processes for meat. One-centimeter square cross section samples were cut parallel to the muscle fiber orientation across the complete cross sectional area of cooked strip loin steaks. Each sample was assigned a coordinate reference grid code that identified (“mapped”) its location within the steak. Shear force measurements within steaks were evaluated using the SMM procedure before and after applying the hydrodynamic pressure (HDP) tenderization process. The less tender the region within a control steak, the more it was tenderized after applying HDP, and HDP tenderization resulted in improved uniformity of tenderness. The suggested SMM method has the potential to minimize variations in technique among scientists and institutions and provides a tool for screening and testing the efficiency of tenderization processes by evaluating a larger proportion.

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    ABSTRACT: The i.m. tenderness variation was examined within four beef chuck muscles, the infraspinatus (IF), supraspinatus (SS), triceps brachii (TB), and serratus ventralis (SV). The IF, SS, TB, and SV muscles were cut into 2.5 cm thick steaks perpendicular to the long axis of the muscle. An identification tag was placed on each steak, consisting of a muscle identification number, steak number, and orientation of the steak. Steaks were vacuum-packaged and stored at -22 degrees C until subsequent analysis. Steaks were thawed at 1 degrees C and cooked on electric broilers to an internal temperature of 71 degrees C. One core was removed from each 2.5-cm x 2.5-cm section parallel to the muscle fiber and sheared once to determine Warner-Bratzler shear force (WBSF). The SS had an overall WBSF mean of 5.43 kg (SD = 2.20 kg) with no tenderness difference (P = 0.43) among steak locations. The IF had an overall WBSF mean of 3.16 kg (SD = 1.01 kg) with no tenderness difference (P = 0.51) among steak locations. The SV had a mean WBSF value of 4.37 kg (SD = 1.27 kg) with tenderness variation (P < 0.05) among steak locations; however, tenderness variations were not dispersed in a discernible pattern. The TB had a mean WBSF value of 4.12 kg (SD = 1.26 kg) with lower (P < 0.05) shear force in the middle region of the TB, and the distal and proximal ends were tougher (P < 0.05). Results of this study provided a reasonably detailed mapping of the tenderness regions within the IF, SS, TB, and SV muscles, and this information could be used to add value to the beef chuck by cutting and marketing consistently tender regions.
    Journal of Animal Science 01/2006; 83(12):2835-42. · 2.09 Impact Factor
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    ABSTRACT: Enhanced ionospheric effects may exist during space weather events, leading to degradations in GPS performance and positioning accuracies. This issue is a concern for reliable operation of safety-critical GPS systems, such as marine DGPS services or Satellite-Based Augmentation Systems (SBAS) for aviation applications. These storm-related effects tend to peak in the years following solar maximum, and will continue to be a concern for GPS applications over the next few years (2002-2003). In order to provide timely predictions of space weather events, we have recently investigated an ionospheric warning and alert system for GPS applications. Predictive capabilities are based on space weather parameters provided by the United States Space Environment Center at NOAA. The impact of ionospheric activity on GPS performance has been quantified using several years of GPS data from the North American sector, with a focus on marine and aviation applications. We have established strong correlations between GPS performance and various ionospheric phenomena, and we are able to provide space weather predictions for GPS users up to six hours in advance.
    Position Location and Navigation Symposium, 2002 IEEE; 02/2002
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    ABSTRACT: A novel approach to mapping Warner-Bratzler shear of whole muscles was explored. The procedure was used on the Longissimus thoracis et lumborum (LTL) and Semitendinosus (ST) from six beef cattle by first marking skeletally defined anatomical landmarks on the muscle in situ. After removal from the carcass, further divisions were made while preserving sample orientation during cooking and preparation for shearing. Shear gradients were observed in all planes of the LTL, particularly the medial-lateral. The mid-section of the ST had the lowest shears while superficial locations of the cross-section had greater values. Muscle comparison indicated the ST was more uniform than the LTL. The mapping technique was subsequently used to identify localized effects of altered carcass suspension on shear values and sarcomere length in the lumbar Longissimus from four beef cattle. This mapping method will provide guidance for further intensive investigation across the carcass musculature and under varying carcass conditions.
    Meat Science 01/2006; 72(1):79-90. · 2.75 Impact Factor


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