Location: Meats Safety & Quality Research2011 Annual Report
1a. Objectives (from AD-416)
1. Develop and evaluate non-invasive instrumentation to predict value determining characteristics of meat. a. Develop and evaluate non-invasive instrumentation to measure maturity and lean color for on-line quality grade determination of beef carcasses. b. Continue improving our non-invasive instrumentation to predict meat tenderness and expand its capabilities to include use on multiple quality grades, muscles, and species. c. Develop technology to predict and improve lean color stability in beef. d. Determine the relationship between instrumental assessment of beef carcass yield grade and wholesale rib dissection-based estimates of beef carcass retail product yield. 2. Develop strategies to optimize meat quality and composition traits of meat. a. Develop strategies to improve the value of underutilized muscles. b. Validate that the µ-calpain and calpastatin tenderness markers that were developed and have been verified in structured research populations will be efficacious when applied to the diverse genetics, management systems, and harvesting conditions that occur in the U.S. beef industry. c. Determine the level of differences among lamb breeds in biochemical traits controlling variation in tenderness and develop strategies to exploit these differences to optimize lamb quality and carcass composition.
1b. Approach (from AD-416)
The VBG2000 image analysis system will be used to develop measurements for carcass maturity and lean color for quality grade determinations of beef carcasses. The VBG2000 system will be used to obtain instrumental measurement of retail product yield for use in genomic analyses. Non-invasive meat tenderness prediction will be expanded to include measurement on U.S. Choice beef carcasses, pork loins, and muscles in addition to longissimus. Strategies to predict and improve lean color stability of beef will be developed. The relative role of connective tissue, muscle shortening, and postmortem proteolysis and their interaction with one another on tenderness of various muscles will be used to develop muscle specific quality improvement strategies to overcome both within and among muscle variation. These strategies may include combinations of antemortem management and genetics utilization as well as postmortem processing methods, marination, and cooking methods to optimize meat tenderness. The µ-calpain and calpastatin tenderness markers that were developed and have been verified in structured research populations will be validated to be efficacious when applied to the diverse genetics, management systems, and harvesting conditions that occur in the U.S. beef industry. The level of differences among lamb breeds in biochemical traits controlling variation in tenderness will be determined and strategies to exploit these differences to optimize lamb quality and carcass composition will be developed.
3. Progress Report
In FY 2011, research was conducted to expand the use of the U.S. Meat Animal Research Center (USMARC) noninvasive tenderness prediction system to predict lean color stability of pork loin chops. This research resulted in a robust prediction model that consistently segregates pork loins into groups with regard to retail lean color stability when boneless loins are produced 24 hours after harvest. This work also produced models that could be applied to aged loins, as well as to aged chops. This indicates that this technology could be used to sort loins prior to distribution or to evaluate loins already in the distribution system. Furthermore, the chop model could be used for product evaluation of chops already in retail packages. Trials indicated that pork loin chops from carcasses produced in plants utilizing rapid chilling systems were less tender than those from carcasses produced in plants utilizing conventional chilling methods. Pigs from a common source were transported equal distances to three processing plants differing in the chilling methods. Vacuum-packaged loins were aged and tenderness was measured objectively with slice shear force at 15 days after harvest, which is approximately the average time between harvest and retail consumption of loin chops. Chops from loins produced in the plant using rapid chilling systems were tougher than those from loins produced in the plant using conventional chilling systems. Furthermore, work on the contribution of animal effects on lean color stability determined that lean color stability measurements were highly repeatable. Duplicate top loin steaks from each of 100 beef carcasses were placed in simulated retail display during which lean color change was measured. Color change was highly repeatable indicating that simulated retail display data are suitable for use in genomic studies. Further work determined that postmortem aging has a profound detrimental effect on retail color life. In this experiment, top loin steaks were removed from 100 beef carcasses after grading and placed in simulated retail display. The strip loin was then obtained after fabrication and aged for 14 days before a second steak was placed in simulated retail display. The remaining portion of each loin was repackaged and aged until 35 days postmortem before a third steak was placed in simulated retail display. The rate and extent of discoloration during simulated retail display differed greatly between aging times. However, discoloration was highly correlated across aging times. Thus, findings from display studies utilizing steaks produced under one set of aging parameters can be applied to steaks produced under other parameters. One important implication of this work is that retail color stability measurements can be readily incorporated into our current data collection protocols for genomic studies without increasing costs or decreasing sample numbers.
1. Technology can accurately predict the lean color stability of pork loin chops. As display case-ready packaging continues to increase in the retail sector of the red meat industry, customer expectations for retail color-life of meat products increases. Some pork carcasses do not possess adequate color-life to meet specifications for case-ready product lines and are a significant cost to the industry. To this end, the industry needs non-invasive instrumentation to sort boneless pork loins with regard to lean color stability. ARS scientists at Clay Center, NE, developed a technology to predict tenderness of beef and pork and in collaboration with the National Pork Board they further developed the instrument to predict the lean color stability of pork loins. The instrument could be used to identify premium products for the retail sector thereby resulting in substantial savings to the industry by reducing the amount of product discarded due to off-color.
2. Rapid chilling of pork carcasses reduced the tenderness of pork loin chops. Very rapid chilling of pork carcasses has been widely adopted by the pork industry as a means to improve throughput, food safety, and color attributes of pork products. However, decreased tenderness has been identified as a source of consumer dissatisfaction with pork products. ARS scientists at Clay Center, NE, have demonstrated that pork loins produced in plants using rapid chilling systems are less tender than those produced in plants using conventional chilling systems. This research identified very rapid chilling as a large contributor to pork tenderness variation. These results led the National Pork Board and industry to collaborate with ARS to find solutions to this problem.
King, D.A., Shackelford, S.D., Rodriguez, A.B., Wheeler, T.L. 2011. Effect of time of measurement on the relationship between metmyoglobin reducing activity and oxygen consumption to instrumental measures of beef longissimus color stability. Meat Science. 87(1):26-32.