2007 Annual Report 1a.Objectives (from AD-416) The primary goal for this project is to develop a pressure based technology that will improve the quality of fresh, frozen or further processed muscle food products to fully achieve their value-added capabilities. Specific objectives are: (1) Develop non-explosive, non-pyrotechnic pressure technologies that will improve the quality of fresh and frozen meat products using hydrodynamic pressure processing (HDP) technology as the benchmark pressure application, (2) develop pressure technologies that will improve the quality and shelf-life of further processed meat products and fully achieve the value-added capabilities of these technologies. Evaluate the effect of these technologies with companion preservation technologies being evaluated in the unit's food safety CRIS, (3) characterize the alterations in molecular and structural properties of meat products subjected to the technologies developed and described in objective 1. 1b.Approach (from AD-416) The effect of pressure on fresh and frozen/thawed muscle tissue will be characterized using biochemical, physical and chemical properties to determine their relationship with exposure to pressure in order to ascertain the correlation to successful meat quality enhancements (e.g., tenderness). The application of pressure processing to finished processed meat products either to raw ingredients before processing or directly to the finished product to determine where pressure processing would be most beneficial to enhance quality and shelf-life and fully achieve value-added benefits. Using hydrodynamic pressure processing as the benchmark pressure application, non-explosive, non-pyrotechnic pressure technologies will be developed and evaluated for successful quality improvements of fresh and frozen meat products. 4.Accomplishments A study evaluating the effects of pressure processing and aging on pork loin quality was completed. Pressure processing was shown to enhance aging tenderization while having minimal effects on important quality characteristics such as water-holding capacity and fresh meat color which is a positive and significant impact. Analyzing the effects of pressure processing and aging on the muscle protein characteristics of the pork loins demonstrated that pressure enhances aging related myofibrillar protein degradation and influences protein solubility. A second study investigating the effects of pressure processing on the meat quality and processing characteristics of marinated pork loins was also conducted. Protein analyses of this study are ongoing. The combined results of the pork loin study and a completed study on the effects of pressure processing on beef strip loins suggest that pressure tenderizes meat by physically disrupting the muscle ultrastructure at the cellular level and enhances postmortem aging tenderization through increased substrate availability. Furthermore, alterations in the sarcoplasmic protein profiles in beef strip loins were found to be associated with positive changes in tenderness. Studies were initiated to further investigate the potential for using muscle protein changes associated with pressure processing and aging tenderization as potential predictors for tenderness indicators. This research relates to National Program 306 Quality and Utilization of Agricultural Products with research components of quality characterization, preservation and ehnancement in addition to value-added foods. 5.Significant Activities that Support Special Target Populations None 6.Technology Transfer Number of U.S. patents granted 1 Number of web sites managed 1 Number of non-peer reviewed presentations and proceedings 8 Number of newspaper articles and other presentations for non-science audiences 2