Progress 03/22/02 to 09/30/09
Outputs
OUTPUTS: The primary objectives of this project were to improve the value, quality and safety of meat products. This was accomplished by identifying in situ bovine and porcine myofibrillar enzymes for a multi-antigen assay to validate heating endpoints achieved during cooking, evaluating various pathogen interventions for bacteriostatic and bactericidal properties, determining antioxidant capacity of plant derived phytochemicals in processed meats as compared to traditional antioxidants, assessing the effectiveness of FDA/USDA approved ingredients to sustain fresh meat color, developing a rapid biomechanical compression technique to predict bovine muscle tenderness and validating the accuracy of a rapid microwave/ nuclear magnetic resonance (NMR) analytical method for moisture and fat analysis to that of classical wet-chemistry techniques. Significant outputs have been disseminated to potential users through peer-review journal articles, presentations at national professional societies (American Meat Science Association, Institute of Food Technologists, Association of Official Analytical Chemists, American Society of Animal Science), international meetings (International Congress of Meat Science and Technology, Fi FOOD SUMMIT, International Association of Food Protection), meat industry seminars (National Meat Association, American Meat Institute Foundation) and short courses. PARTICIPANTS: Jimmy T. Keeton, Professor, Department of Nutrition and Food Science, - PI Rhonda Miller - Professor, Department of Animal Science - Co-PI Steven Smith - Professor, Department of Animal Science - Co-PI Jeff Savell - Professor, Department of Animal Science - Co-PI Marcos Sanchez - Associate Professor, Department of Poultry Science - Co-PI Margaret Hardin - Associate Professor, Department of Animal Science - Co-PI Wesley Osburn - Associate Professor, Department of Animal Science - Co-PI Nathan Bryan - Institute of Molecular Medicine, University of Texas, Houston Health Science Center, Houston, TX Maryuri Nunez de Gonzalez - Professor and Visiting Scientist, Universidad de Oriente, Nucleo Nueva Esparta, Venezuela Douglas Miller - Research Scientist, Department of Animal Science TARGET AUDIENCES: Information generated from research studies described has been disseminated in the form of final reports to sponsoring organizations, peer reviewed scientific manuscripts (Journal of Food Science, Meat Science, Food Chemistry, Journal of the Association of Official Analytical Chemists, Journal of Food Protection, Poultry Science, Journal of Texture Studies) and media presentations (newsletters, trade publications, e-magazines) that serve the meat and poultry industry. Additional dissemination will be made through short courses, workshops and events sponsored by Texas AgriLife Extension. Results are also being shared with professional trade associations such as the Institute of Food Technologists, National Pork Board, American Meat Institute Foundation, National Cattlemen's Beef Association, California Dried Plum Board, National Meat Association and similar commodity based organizations. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The most significant outcomes from individual studies are described as follows. Four in situ proteins, bovine serum albumin, bovine lactate dehydrogenase (LDH-5), porcine enolase and bovine myoglobin were identified and exhibited predictable denaturation/ precipitation patterns with increased heating from 63 to 79 degrees Celsius. Monoclonal antibodies (Mabs) from each protein were produced for use in a multi-antigen ELISA to correlate protein concentration decline with increases in meat cooking temperature. Complete configuration of an ELISA to test sufficiency of heating and ensure pathogen destruction was not possible due to expiration of funding. However, configuration of Mabs into a solid phase test strip for cooked meat fluid could potentially prove successful and provide a rapid assay to verify sufficiency of heating to destroy pathogens. Acidified calcium sulfate (ACS) with propionic or lactic acid, when applied to frankfurters with or without sodium lactate immediately prior to vacuum packaging, suppressed growth of Listeria monocytogenes (LM) with minimal sensory effects on the product, thus providing an enhanced margin of safety for products opened at home and held by consumers. Likewise, inclusion of potassium lactate (KL) and sodium diacetate in frankfurter formulations in combination with pasteurizing doses of irradiation were shown to be very effective for controlling the growth of LM while maintaining desirable sensory characteristics. A sequential hot spray application of ACS and epsilon polylysine (EPL) to fresh prerigor beef was shown to be more bactericidal against Escherichia coli 0157:H7 (EC), Salmonella Typhimurium (ST) and LM than LA alone. This multi-hurdle approach could enhance the safety of fresh beef products. Incorporation of dried plum puree into precooked pork sausage and fresh irradiated beef patties, and plum juice concentrates into precooked roast beef suppressed lipid oxidation during refrigerated or frozen storage as well as a combination of butylated hydroxyanisole/ butylated hydroxy toluene (BHA/BHT). Naturally occurring polyphenolics in plum products were believed to be the active compounds suppressing lipid oxidation. An evaluation of three metabolically different bovine muscles having incremental levels of lactate dehydrogenase (LDH) and treated with varying levels of KL showed that treatments which enhance LDH activity and generate NADH can prolong desirable beef color, but not beyond the point of spoilage. Preserving the desirable color of beef could allow for longer distribution times, reduce discounted product at retail and enhance consumer satisfaction. A 3 percent biomechanical compression applied to the surface of raw Longissimus dorsi muscle segments for a few seconds was more effective than Warner-Bratzler Shear Force for predicting sensory tenderness. Further development of this technique could provide and in-line assessment of tenderness and allow for selection and segregation of carcasses on the basis of tenderness prior to fabrication.
Publications
- Nunez, M.T., Keeton, J.T., Hafley, B.H., Boleman, R.M. and Rhee, K.S. 2009. Qualitative effects of fresh and dried plum ingredients on vacuum packaged sliced hams. Meat Sci. 83:74-81.
- Chae, S.H., Keeton, J.T., Miller, R.K., Johnson, D. Maxim, J., and Smith. S.B. 2009. The triacylglycerol preparation of conjugated linoleic acid reduces lipid oxidation in irradiated, cooked ground beef patties. Meat Science 81:647-652.
- Kim, Y. H., Keeton, J. T., Yang, H. S., Smith, S. B., Sawer, J., Savell, J. W. 2009. Color stability and biochemical characteristics of bovine muscles when enhanced with L- or D-potassium lactate in high-oxygen modified atmospheres. Meat Sci. 82:234-240.
- Kim, Y.H., Keeton, J.T., Smith, S.B., Berghman, L.R. and Savell, J.W. 2009. Role of lactate dehydrogenase in metmyoglobin reduction and color stability in different bovine muscles. Meat Sci. 83:376-382.
- Kim, Y.H., Keeton, J.T., Hunt, M.C., Savell, J.W. 2010. Effects of L- or D-lactate on the internal cooked color stability and biochemical characteristics of beef steaks in high oxygen modified atmospheres. Food Chem. 119 (3):119-122.
- Brandt, A.L., Hardin, M.D., Castillo, A., Harris, K.B., Keeton, J.T., and Taylor, T.M. 2009. In vitro inhibition of Listeria monocytogenes with acidic calcium sulfate combined with Nisin or epsilon-poly-L-lysine. International Association of Food Protection, Grapevine, TX, July 12-15, 2009.
- Brandt, A.L., Hardin, M.D., Castillo, A., Harris, K.B., Keeton, J.T., and Taylor, T.M. 2009. In vitro inhibition of Listeria monocytogenes exposed to octanoic acid and acidic calcium sulfate alone and in combination. International Association of Food Protection, Grapevine, TX, July 12-15, 2009.
- Benli, H., Castillo, A. and Keeton, J.T. 2009. Reduction of Escherichia coli O157:H7 and Salmonella typhimurium on beef surfaces and in ground beef using sequential spray application of epsilon-polylysine or lauric arginate followed by acidic calcium sulfate. Reciprocal Meat Conference of the American Meat Science Association, University of Arkansas, June 21-24, 2009.
- Brandt, A.L., Hardin, M.D., Castillo, A., Harris, K.B., Keeton, J.T. and Taylor, T.M. 2009. In vitro inhibition of Listeria monocytogenes with acidic calcium sulfate combined with nisin or epsilon-polylysine. Poster Presentation. P3-57. International Association for Food Protection Annual Meeting, Grapevine, TX: July 12-15.
- Brandt, A.L., Hardin, M.D., Castillo, A., Harris, K.B., Keeton, J.T. and Taylor, T.M. 2009. In vitro inhibition of Listeria monocytogenes exposed to octanoic acid and acidic calcium sulfate alone and in combination. Oral Presentation. T2-03. International Association for Food Protection Annual Meeting, Grapevine, TX: July 12-15.
- Brandt, A.L., Hardin, M.D., Castillo, A., Harris, K.B., Keeton, J.T. and Taylor, T.M. 2009. In vitro inhibition of Listeria monocytogenes with acidic calcium sulfate combined with nisin or epsilon-poly-L-lysine. Poster Presentation. TP-03G. Texas A&M University Graduate Student Council Student Research Week, College Station, TX: March 23-27.
- Keeton, Jimmy T. and Wesley N. Osburn. Formed Emulsion Products. Chapter in Poultry Meat Processing, 2nd Edition. Christie Alvarado and Casey Owens Editors. CRC Press, Boca Raton, FL. Summer 2009.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: The primary objectives of this project are to improve the value and safety of meat products. The effectiveness of natural antioxidant ingredients were evaluated in Semimembranosus and Adductor beef roasts by injecting 20 percent by weight with a brine containing no plum ingredient; 2.5 or 5 percent fresh plum juice concentrate (FP); 2.5 or 5 percent dried plum juice concentrate (DP); or 2.5 or 5 percent spray dried plum powder (PP). Whole, cooked, vacuum-packaged roasts were stored at 4.0 degrees Celsius for 10 weeks. Evaluations were performed at 2 week intervals on sliced product to determine purge, shear force, lipid oxidation (TBARS), instrumental color, and sensory attributes. To determine the influence of calcium lactate (CL) on color stability and lipid oxidation, beef strip loins were divided into sections and randomly assigned to one of 6 treatments - control; 0.3 percent phosphate (PHOS); 0.2 percent calcium lactate (CL), 0.3 percent PHOS; irradiated (2.4kGy) non-injected control; irradiated, 0.2 percent CL; and irradiated, 0.2 percent CL, 0.3 percent PHOS. Loins were sequentially injected with CL followed by PHOS at 10 percent of raw weight. Steaks from each loin section were packaged under 80 percent oxygen (MAP), irradiated (2.4kGy), stored 10 days at 1 degrees Celsius, then displayed 5 days at 1 degree Celsius under 2150 lux fluorescent light. Instrumental surface color, total reducing activity (TRA), 2-thiobarbituric acid value (TBARS), and NADH concentration were determined. Multi-hurdle spray applications of epsilon polylysine (EPL), lauric arginate (LAE) and acidic calcium sulfate (ACS) solutions were evaluated for their effectiveness against Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) on inoculated broiler carcasses, and against ST and Escherichia coli O157:H7 (EC) on beef rounds as well as ground beef derived from treated rounds. All possible 2-way combinations and individual applications of 30 percent ACS (ACS30), 300 mg per liter EPL (EPL300) and 200 mg per liter LAE (LAE200) were evaluated. A national survey is underway to randomly sample the major categories of cured meat products for nitrite-nitrate content. Five, highly consumed raw vegetables also will be sampled to establish a current nitrate-nitrite database for cured meat and vegetables. These data will be compared to historic databases to determine the contributions of these food sources to the daily dietary intake of nitrite-nitrate. A companion survey of the nitrite-nitrate concentrations of potable water supplies from 20 different cities across the U.S. has been completed. Research from completed studies have been published in peer-reviewed scientific journals, industry trade publications and e-magazines, forwarded to commodity support groups and provided to corporations interested in the technological outcomes. PARTICIPANTS: Individuals: Jimmy T. Keeton, Professor, Department of Nutrition and Food Science, - PI; Rhonda Miller - Professor, Department of Animal Science - Co-PI; Steven Smith - Professor, Department of Animal Science - Co-PI; Jeff Savell - Professor, Department of Animal Science - Co-PI; Marcos Sanchez - Associate Professor, Department of Poultry Science - Co-PI; Margaret Hardin - Associate Professor, Department of Animal Science - Co-PI; Wesley Osburn - Associate Professor, Department of Animal Science - Co-PI Nathan Bryan - Institute of Molecular Medicine, University of Texas, Houston Health Science Center, Houston, TX; Maryuri Nunez de Gonzalez - Professor and Visiting Scientist, Universidad de Oriente, Nucleo Nueva Esparta, Venezuela Partner Organizations: American Meat Institute Foundation, National Pork Board, National Cattlemen's Beef Association, California Dried Plum Board, E. M. "Manny" Rosenthal Chair in Animal Science and the Manny and Rosalyn Rosenthal Endowed Fund in the Department of Animal Science Collaborators: Tim Leffler - CEM Corporation; Cindy Moser - CEM Corporation; Bobby McManus - CEM Corporation; John Urh - CEM Corporation; Gary Acuff - Professor and Head, Department of Animal Science; Lisa Lucia - Research Associate, Department of Animal Science Training and Professional Development: Hakan Benli - Ph.D.; Y. H. "Brad" Kim - Ph.D.; Amy Claflin - M.S. Graduate Student; E. Cabrera-Diaz - M.S. Graduate Student TARGET AUDIENCES: Information generated from the research studies described has been disseminated in the form of final reports to sponsoring organizations, peer reviewed scientific manuscripts (Journal of Food Science, Meat Science, and Food Chemistry) and media presentations (newsletters, trade publications, e-magazines) that serve the meat and poultry industry. Additional dissemination will be made through short courses, workshops and events sponsored by Texas AgriLife Extension. Results are also being shared with professional trade associations such as the Institute of Food Technologists, National Pork Board, American Meat Institute Foundation, National Cattlemen's Beef Association, California Dried Plum Board and similar commodity based organizations. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Naturally derived plum ingredients were found to reduce oxidative rancidity and had minimal effects on tenderness, sensory characteristics, color and appearance of beef roasts. Minor changes in purge, color, TBARS and some sensory properties were observed during storage of roasts. Overall results indicate that 2.5 percent fresh plum juice concentrate (FP) or dried plum juice concentrate (DP) could be incorporated into precooked beef roasts as a natural antioxidant to reduce lipid oxidation and potentially retard warmed-over flavor (WOF) in precooked beef products. Injection of beef loins with calcium lactate (CL) and phosphate (PHOS) was found to maintain stable red color during storage and display time. Loins with CL plus PHOS were the least oxidized and had increased NADH concentration that in turn maintained a desirable color pigment form. Even under highly oxidizing conditions (high oxygen MAP with irradiation), CL with PHOS minimized lipid oxidation, increased NADH and TRA and had higher redness values compared to other irradiated treatments. Lactate inclusion was shown to improve color stability by providing increased antioxidant capacity and myoglobin reducing activity via elevated NADH levels. Spraying inoculated poultry carcasses with EPL300ACS30 or LAE200ACS30 was found to reduce initial Salmonella counts by 1.5 and 1.8 log CFU per ml, respectively, and by 1.2 and 1.8 log CFU per ml, respectively, after 6 days of storage at 4.4 degrees Celsius. Reductions in resident microflora on uninoculated carcasses as determined by aerobic plate counts, E. coli, coliform and psychrotroph counts indicate that these treatments have the potential to increase poultry carcass shelf-life. Application of warm (55 degrees Celsius) EPL300ACS30 or LAE200ACS30 to inoculated beef rounds reduced ST and EC counts over 6 days storage at 4.4 degrees Celsius by 4.5 and 4.3 log CFU per square cm, respectively. Ground beef manufactured with EPL300ACS30 or LAE200ACS30 treated rounds had lower ST and EC counts initially and stayed lower over 4 days storage at 4.4 degrees Celsius. Combined antimicrobial treatments were more effective than single applications. A national survey of cured meat, raw vegetables and municipal water supplies will document the actual contributions of nitrate-nitrite to the daily dietary nitrate-nitrite load of consumers and validate the limited contribution of cured meat products to this load.
Publications
- Benli, Hakan. 2008. Sequential Application of Epsilon Polylysine, Lauric Arginate and Acidic Calcium Sulfate for Inactivation of Pathogens on Raw Chicken and Beef. Ph.D. Dissertation. Texas A&M University, College Station, TX
- Kim, Y.H., Keeton, J.T. and Savell, J.W. 2008. Improvement of color stability of bovine muscles through lactate-LDH system. Institute of Food Technologist, New Orleans, LA, June 28-July 2, 2008.
- Hakan B., Gomes, C.I., Kakani, G., Chmielewski, G., Sanchez-Plata, M.X. and Keeton, J.T. 2008. Efficacy of epsilon polylysine, lauric arginate or acidic calcium sulfate applied sequentially for salmonella reduction on membrane filters and chicken carcasses. Institute of Food Technologist, New Orleans, LA, June 28-July 2, 2008.
- Rodriguez, G., Faget, S., Rosazza, C. Sander, C., Meiberg, J., Keeton, J.T., and Kim, Y.H. 2008. Verification of the mechanism of lactate on metmyoglobin-reducing activity and color stability of fresh bovine extracts. American Meat Science Association, University of Florida, June 21-25, 2008.
- Kim, Y.H., Keeton, J.T. and Savell, J.W. 2008. Evaluation of antioxidant capacity and color stability of calcium lactate on fresh beef under highly oxidizing conditions. American Meat Science Association, University of Florida, June 21-25, 2008.
- Kim, Y.H., Keeton, J.T. and Savell, J.W. 2008. Prevention of internal premature browning in cooked steaks packaged in high-oxygen modified atmosphere by increasing reducing ability through lactate enhancement. American Society of Animal Science, Indianapolis, IN, July 7-11, 2008.
- Nunez de Gonzalez, M.T., Boleman, R.M., Miller, R.K., Keeton, J.T. and Rhee, K.S. 2008. Antioxidant properties of dried plum ingredients in fresh and precooked pork sausage. J. Food Sci. 73 (5):H63-71
- Nunez de Gonzalez, M.T. Hafley, B.S., Boleman, R.M., Miller, R.K., Rhee, K.S. and Keeton, J.T. 2008. Antioxidant properties of plum concentrates and powder in precooked roast beef to reduce lipid oxidation. Meat Sci. 80 (4):997-1004
- Leffler, T.P., Moser, C.R., McManus, B.J., Urh J.J., Keeton, J.T. and Claflin, A.E. 2008. Determination of moisture and fat in meats by microwave and nuclear magnetic resonance analysis: Collaborative study. AOAC Official Method 2008.06. Journal AOAC International 91(4):802-810.
- Kim, Y.H., Keeton, J.T., Smith, S.B., Maxim, J.W., Yang, H.S. and Savell, J.W. 2009. Evaluation of antioxidant capacity of calcium lactate enhancement on fresh beef under highly oxidizing conditions. Food Chemistry 115:272-278.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Biomechanical measurements and microbiological evaluations were performed on natural hog casings exposed to ozonated water (7 mg ozone per liter) for 0, 2 or 4 hours at 16 degrees Celsius. Bursting strength and maximum rupture force values indicated that casings could be treated with ozone up to 2 hours without deterioration and that ozonation made casings appear lighter. Ozonation for 1 and 2 hours reduced counts of Escherichia coli biotype I by 0.4 and 0.6 log CFU per 25.4 cm of casing, but not sufficient to be an effective antimicrobial treatment. Chubs of raw pork sausage with 0, 3 or 6 percent dried plum puree (DP), 3 or 6 percent dried plum and apple puree (DPA) or 0.02 percent butylated hydroxytoluene and butylated hydroxyanisole (BHA, BHT) were stored at 4 degrees Celsius (RR) and evaluated weekly over 28 days. Cooked, vacuum packaged patties were stored at 4 degrees Celsius (PR) for weekly evaluation over 28 days, or stored at minus 20 degrees Celsius (PF) and
evaluated monthly over 90 days. DP at 3 or 6 percent was as effective as BHA and BHT for retarding lipid oxidation in PR and PF sausage patties. DP at 6 percent was a more effective antioxidant than BHA, BHT in PF patties. Patties with 3 percent DP or DPA were as acceptable to consumers as the control or those with BHA, BHT, but patties with 6 percent DP or DPA were less desirable. DP at 3 percent was as effective as BHA, BHT for suppressing lipid oxidation in precooked pork sausage patties. Color stability of different muscles could be due to the rate of replenishment of NADH via different lactate dehydrogenase (LDH) activities in bovine muscles. Longissimus dorsi (LD), Semimembranosus (SM), Psoas major (PM) were fabricated 5 days postmortem, cut into steaks, PVC packaged, and displayed 7 days at 1 degree Celsius. LD showed the least metmyoglobin accumulation and was reddest over time followed by SM. PM was most discolored with the lowest metmyoglobin reducing activity (MRA). LD had
more LDH B activity in the pyruvate direction, produced more NADH and had greater MRA. PM had higher pH and WHC compared to LD and SM. Results suggest that LDH involves the MRA system by replenishing NADH. Although, PM had a higher pH and WHC, it had the least color stability and lowest MRA possibly due to lower LDH B activity and subsequently lower NADH regeneration. Paired combinations of acidified calcium sulfate (ACS), epsilon-polylysine (EPL) or lauramide arginine ethyl ester (LAE) solutions were sprayed onto warm poultry carcasses to reduce surface inoculations of Salmonella Enteritidis and Salmonella Typhimurium. LAE (200 mg per liter) followed by 30 percent ACS after 40 seconds, EPL (300 mg per liter) followed by 30 percent ACS and 30 percent ACS alone showed the largest reductions in Salmonella by 2.1, 2.1 and 2.3 log CFU per milliter. EPL and ACS or LAE and ACS combinations reduced TPC and psychrotrophs on carcasses after 10 days refrigerated storage. Sequential application
of combined antimicrobial interventions were more effective for reducing Salmonella and extending shelf-life of poultry carcasses.
PARTICIPANTS: Individuals: Jimmy T. Keeton, Professor, Department of Nutrition and Food Science, - PI Douglas Miller - Research Scientist, Department of Animal Science - Co-PI Rhonda Miller - Professor, Department of Animal Science - Co-PI Steven Smith - Professor, Department of Animal Science - Co-PI Jeff Savell - Professor, Department of Animal Science - Co-PI Marcos Sanchez - Associate Professor, Department of Poultry Science - Co-PI Partner Organizations: International Scientific Working Group of the Natural Sausage Casing Industry U.S. Poultry and Egg Association National Cattlemen's Beef Association California Dried Plum Board Collaborators: Tim Leffler - CEM Corporation Cindy Moser - CEM Corporation Bobby McManus - CEM Corporation John Urh - CEM Corporation Gary Acuff - Professor and Head, Department of Animal Science Lisa Lucia - Research Associate, Department of Animal Science Training and Professional Development: Amy Claflin - M.S. Graduate Student E. Cabrera-Diaz - M.S.
Graduate Student Y. H. Brad Kim - Ph.D. Graduate Student Hakan Benli - Ph.D. Graduate Student Brian Hafley - Ph.D. Graduate Student
TARGET AUDIENCES: Dissemination of the information generated from this research is being prepared in the form of final reports to sponsoring organizations, scientific journal articles that emphasize food safety (manuscripts are currently pending review in the Journal of Food Protection, Journal of Food Science, Journal of Agriculture and Food Chemistry, and Meat Science) and media channels (newsletters, trade magazines) that serve the meat and poultry industry. Additional dissemination will be made through short courses, workshops and events sponsored by the Texas AgriLife Extension. Results are also being sent to associations such as the International Scientific Working Group of the Natural Sausage Casing Industry, U.S. Poultry and Egg Association, National Cattlemen's Beef Association, California Dried Plum Board and similar commodity based organizations.
PROJECT MODIFICATIONS: No major changes were made in the overall project.
Impacts
Ozonated water is used in meat processing environments to decontaminate food contact surfaces and could potentially reduce the pathogen and spoilage bacteria load on natural hog casings. Our research established that casings could be exposed to 7ppm ozone for up to 2 hours without detrimental physical effects to the casing when treated with chilled, ozonated water. Total bacterial reductions of an indicator organism on casings were marginal, but the casings did appear lighter due to ozone treatment. Ozonation, in combination with other treatments, could prove beneficial for reducing pathogenic and spoilage bacteria on natural casings, but not as a single antimicrobial treatment. Meat surface discoloration due to premature metmyoglobin formation prior to spoilage is considered as one of primary causes of lost retail sales of fresh meat. Metmyoglobin can be converted to deoxy-oxy-myoglobin through the metmyoglobin reducing activity (MRA) of muscle with NADH as an
ultimate substrate for MRA. Results from our preliminary studies with three bovine muscles having different levels of lactate dehydrogenase (LDH) activity suggest that LDH influences the metmyoglobin reduction system by replenishing NADH and extending the desirable color of beef. Treatments that enhance LDH activity to generate NADH could prolong the red color of meat, but not beyond the point of spoilage. Preserving the natural color of beef could allow for broader distribution of product, reduce discounted sales and enhance consumer satisfaction. Salmonella contamination continues to be one of the major concerns for the microbiological safety of poultry products. It has been reported that a combination of antimicrobials might work better than individual applications due to potential synergistic effects on bacterial inactivation. To evaluate this premise, sequential, paired spray applications of acidified calcium sulfate (ACS), epsilon-polylysine (EPL) or lauramide arginine ethyl
ester (LAE) solutions were evaluated against Salmonella Enteritidis and Salmonella Typhimurium inoculated onto fresh broiler carcasses. Sequential application of combined interventions of LAE and ACS or EPL and ACS were more effective for reducing Salmonella and extending shelf-life of poultry carcasses that any treatment alone or other antimicrobial combinations. Utilization of these treatments on fresh poultry carcasses could prove synergistic with other interventions for more effective control of Salmonella on poultry.
Publications
- Benli, H., Hafley B.S., Keeton, J.T., Lucia, L.M., Cabrera-Diaz, E. and Acuff, G.R. 2007. Biomechanical and microbiological changes in natural hog casings treated with ozone. Meat Science. 79:155-162.
- Kim, Y.H., Keeton, J.T., Smith, S.B., and Savell, J.W. 2007. Color stability and water holding capacity of different bovine muscles and involvement of lactate dehydrogenase in metmyoglobin reduction of muscles. Institute of Food Technologists, Chicago, IL. July 28-August 1, 2007.
- Leffler, T.P., Moser, C.R. McManus, B.J., Urh, J.J., Claflin, Amy E. and Keeton, J.T. 2007. Determination of moisture and fat in meats by microwave and nuclear magnetic resonance analysis. Annual Meeting of the Association of Official Analytical Chemists (AOAC), Anaheim, CA, September 16-20, 2007.
- Keeton, J.T., Hakan Benli and Amy E. Claflin. 2007. Carbohydrates. Chapter 15 in Handbook of Muscle Food Analysis, Part 1. Chemistry and biochemistry. Leo Nollet and Fidel Toldra, Editors. Taylor and Francis Group, Boca Raton, FL.
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Progress 01/01/06 to 12/31/06
Outputs
Biomechanical properties of fresh and aged raw bovine Longissimus dorsi muscles were determined by applying a constant strain of 3% for a few seconds up to four minutes with muscle fibers arranged in parallel and perpendicular orientations. Total energy dissipated and initial and final stiffness of raw steak cubes with designated fiber orientations were calculated using the models and technique of Spadaro (1996) and Spadaro and others (2002), and correlated to overall sensory tenderness scores and Warner-Bratzler Shear Force (WBSF). Linear regression models predicting cooked sensory tenderness were constructed from biomechanical variables. Energy dissipated parallel (EDPL) and initial stiffness perpendicular (ISTFPP) (R squared = 0.74 and R squared = 0.73, respectively) were effective predictors of sensory tenderness whereas WBSF was less effective (R squared = 0.62). Quality attributes were evaluated for irradiated (0, 1.8, or 2.3 kilogray) frankfurters formulated
with 0 or 3 percent added potassium lactate plus sodium diacetate (LAD) and stored aerobically or vacuum packaged at 4 degrees Celsius for 4 and 8 wks. Aroma and flavor quality were retained for aerobically stored frankfurters with LAD throughout their shelf life. Meaty and brothy complex aroma and flavor, smoke aroma and aftertaste, spice aroma and flavor, astringency, sourness, bitterness, springiness, cohesiveness, and juiciness attributes were lower for aerobically stored frankfurters formulated without LAD. Sensory color and other quality attributes were minimally influenced by either treatment. Addition of LAD and irradiation were also effective shelf life extenders for vacuum packaged frankfurters. Overall, LAD retarded deterioration of frankfurters throughout aerobic storage and helped maintain quality with or without irradiation of the vacuum packaged frankfurters. Pre-rigor beef rounds were surface inoculated prior to treatment with a cocktail of rifampicin mutant strains of
Salmonella Typhimurium (ST) strain NVSL 95 1776, E. coli O157:H7 (EC) strain ATTC 43895 and Listeria monocytogenes (LM) Scott A (serotype 4b) at log 6.35 CFU per microorganism per 50 square cm. Five separate hot spray solutions applied at 55 degrees Celsius were tested for effectiveness: sterile distilled water (W), 1:4 acidified calcium sulfate (ACS), 2.5 percent L lactic acid, 100 ppm epsilon polylysine (EPL) and 1:4 ACS followed by 100 ppm EPL. Rounds were refrigerated and sampled at 0, 2 and 7 days post treatment. ACS followed immediately with EPL reduced ST, EC and LM by 2.26, 1.49 and 2.38 logs, respectively, over a 7 day refrigerated storage period. ACS plus EPL applied sequentially were more effective than single treatments of ACS, LA, EPL or W alone. Single treatments of ACS, LA and EPL were more effective than water alone for reducing ST and EC, but only LA was effective against LM. LM appeared to be more sensitive to the initial decontamination treatments on day 0 when
compared to ST and EC.
Impacts
A 3 percent compression technique applied to the surface of raw Longissimus dorsi steaks for a few seconds validated previous algorithms for energy dissipated and initial stiffness. These parameters account for more variation in tenderness than WBSF and provide a more accurate, rapid, less costly, and predictable method of measuring tenderness. Thus, this new method has potential for being a more rapid and objective measure of meat tenderness than mechanical tests currently available. The use of potassium lactate and sodium diacetate in frankfurter formulations in combination with pasteurizing doses of irradiation were influential in maintaining sensory attributes during both aerobic and vacuum packaged storage. These findings validate the use of low dose irradiation in combination with antimicrobials to protect product quality, and provide essential information to the meat industry and regulatory agencies. The sequential application of acidified calcium sulfate (ACS)
and epsilon polylysine (EPL) in the form of a hot spray to pre rigor beef rounds was shown to be more effective against pathogens than a single application of lactic acid, hot water or acidified calcium sulfate. Because ACS and EPL each express a different mode of action for suppressing pathogen growth, sequential application appears more effective than a single application of antimicrobials. This multi hurdle approach to carcass decontamination with more effective antimicrobial agents will enable meat processors and the USDA-FSIS to improve their pathogen intervention strategies.
Publications
- Knight, T.D., Miller, R.K., Maxim, J., and Keeton, J.T. 2007. Sensory and physiochemical characteristics of frankfurters containing potassium lactate and sodium diacetate before and after irradiation. J. Food Sci. Accepted.
- Knight, T.D. Castillo, A., Maxim, J., Miller, R.K., and Keeton, J.T. 2006. Evaluation of frankfurters formulated with potassium lactate and sodium diacetate and inoculated with Listeria monocytogenes before and after irradiation. Abstract. Reciprocal Meat Conference of the American Meat Science Association, University of Illinois, Champaign-Urbana. June 18-21, 2006.
- Boleman, Randi Marburger. An Innovative Approach to Predicting Meat Tenderness Using Biomechanical Properties of Meat. May 2006. Ph.D. Dissertation, Texas A&M University.
- Knight, T.D., Castillo, A., Maxim, J., Keeton, J.T., and Miller, R.K. 2007. Effectiveness of potassium lactate and sodium diacetate in combination with irradiation to control Listeria monocytogenes on frankfurters. J. Food Sci. 72(1):M26-30.
- Njongmeta Nenge, Lynda Azefor, Keeton J.T., Ricke, S.C., Anderson, R.C. and Miller, D.R. 2006. Application of antimicrobials in a hurdle fashion to pre-rigor beef rounds for reduction of pathogens. Abstract. Reciprocal Meat Conference of the American Meat Science Association, University of Illinois, Champaign-Urbana. June 18-21, 2006.
- Ricke, Steven C., Zabala, Irene, Keeton, Jimmy T. 2007. Fermented Meat, Poultry, and Fish Products. Chapter 33 in Food Microbiology: Fundamentals and Frontiers, Third ed. Michael P. Doyle, Larry R. Beuchat and Thomas J. Montville, Editors. AMS Press, Washington, D.C.
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Progress 01/01/05 to 12/31/05
Outputs
Vacuum packaged frankfurters were processed to include 0 or 3 percent potassium lactate sodium diacetate (LD) solution, irradiated to 0, 1.8, or 2.6 kGy and stored 8 wk at 4 degrees Celsius. A second set was inoculated after irradiation and stored aerobically for 4 wk at 4 degrees celsius to simulate product contaminated after opening. LD in the frankfurter formulation and irradiation were effective for controlling growth of L. monocytogenes (Lm) in unopened vacuum packages after 8 wk with only minimal changes in sensory characteristics. Incorporation of LD with or without irradiation had a strong listeriostatic effect throughout 4 wk of aerobic storage. Irradiation treatments alone had higher Lm counts after 3 and 4 wk. Overall, irradiation and LD combined were effective for reducing and retarding Lm growth during vacuum packaged storage. LD, and irradiation to a lesser extent, was effective for retarding Lm throughout aerobic storage. Natural hog casings were
exposed to ozonated water at 6 to 7 mg ozone per liter for 0, 2 or 4 h at 16 degrees Celsius to determine its effect on casing integrity and microbial survival. Ozone decreased casing strength incrementally over 0, 2, and 4 h. Maximum rupture force also decreased, but only after 4 h of ozonation. Casing redness and yellowness decreased after 2 and 4 h making the casings appear lighter. Ozonation was only partially effective for reducing an inoculum of green fluorescing Escherichia coli Biotype 1 and total resident microorganisms. A hot spray 50 to 55 degrees Celsius of acidified calcium sulfate (ACS, RT01), 2.5 percent lactic acid (LA), ACS + 100 microliter epsilon polylysine (EPL), 100 microliter EPL or sterile distilled water (W) was applied to the surface of prerigor beef rounds for 15 to 20 sec at 20 psi. ACS followed with EPL reduced levels of rifampicn-resistant Salmonella Typhimurium, E. coli O157:H7 and Listeria monocytogenes by 1.84, 1.38 and 2.85 logs, respectively. LA, EPL
and ACS alone were not statistically different from hot water. Monoclonal antibodies (Mabs) against lactate dehydrogenase isozyme 5 (LDH 5), serum albumin (SA), myoglobin (Mb) and enolase (E) from beef and pork muscle were developed for use in a sandwich enzyme linked immunosorbent assay (ELISA) to investigate changes in the proteins with incremental increases in heating temperature. The proteins had previously been shown to exhibit differential rates of denaturation with increases in cooking temperature from 63 to 79 degrees Celsius and were selected to develop a ratio model as a means of predicting the endpoint temperature previously achieved in precooked beef or pork products. Six Mabs against LDH 5 had R squared values greater than 0.9 indicating high specificity and affinity for LDH 5. Sandwich ELISA assays developed with cell culture and ascities derived Mabs against BSA, E and Mb were not as successful in a sandwich ELISA. Preliminary data with LDH 5 Mabs, however, suggests
that a multiple antigen ratio model still remains a viable option to predict endpoint temperature when configured with the appropriate Mabs.
Impacts
Potassium lactate and sodium diacetate in frankfurter formulations in combination with pasteurizing doses of irradiation were shown to be very effective for controlling the growth of Listeria monocytogenes on frankfurters while maintaining desirable sensory characteristics. Use of these interventions could enhance the safety of refrigerated RTE products for up to 4 wk if accidentally contaminated after opening. The application of these combined technologies should be considered as a potential intervention strategy to reduce the risk of consumer derived listeriosis. Additional work in our laboratory has shown that a sequential spray application of hot acidified calcium sulfate and epsilon polylysine to the surface of prerigor beef rounds is more effective for reducing pathogens such as Salmonella Typhimurium, E. coli O157:H7 and Listeria monocytogenes than singular applications of approved antimicrobials. This multi hurdle pathogen intervention approach could be
especially useful for small and very small processors because of its ease of use, minimal cost and ease of incorporation into existing processing systems. Further studies are planned to test the sequence of application and exposure time of the antimicrobial applications on the development of pathogen resistance and virulence.
Publications
- Hafley, Brian Scott. Development of Monoclonal Antibodies for a Multiple Antigen ELISA to Verify Safe Cooking End-Point Temperatures in Beef and Pork. Ph.D. Dissertation, Texas A&M University, December 2005.
- Knight, Timothy David. Evaluation of Frankfurters Formulated with Potassium Lactate and Sodium Diacetate and Inoculated with Listeria Monocytogenes Before and After Irradiation Treatment. Ph.D. Dissertation, Texas A&M University, December 2005.
- Benli, H., Hafley, B.S., Keeton, J.T. and Acuff, G.R. 2005. Effects of ozonation on strength and color of natural hog casings. 51st International Congress of Meat Science and Technology. August 7-12, 2005, Baltimore, MD.
- Boleman, R.M., Keeton, J.T., Miller, R.K., Allen, D.H., Searcy, C.R. and Booren, B.L. 2005. An innovative approach to predicting meat tenderness using biomechanical properties of meat. 51st International Congress of Meat Science and Technology. August 7-12, 2005, Baltimore, MD.
- Hemphill, S.P., Shin, D.K., Miller, R.K., Rooney, L.W., Keeton, J.T. and Waniska, R.D. 2005. Effect of sorghum brand addition on lipid oxidation and sensory properties of ground beef patties differing in fat levels. 51st International Congress of Meat Science and Technology. August 7-12, 2005, Baltimore, MD.
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Progress 01/01/04 to 12/31/04
Outputs
Four muscle proteins, lactate dehydrogenase isozyme 5 (LDH 5), serum albumin (SA), myoglobin (Mb) and enolase (E) from beef and pork muscle were found to decrease incrementally under controlled heating conditions to USDA-FSIS specified safe heating endpoints. Purified bovine and porcine LDH 5 and bovine SA were obtained commercially while porcine SA, E and Mb were each purified as antigens for monoclonal antibody (Mab) development. It was theorized that a ratio model comparing the concentration of three or more proteins identified using Mabs in an enzyme linked immunosorbent assay (ELISA) could be used to accurately predict the actual endpoint temperature (EPT) achieved in cooked beef or pork extracts. Mice were immunized against the respective antigens, the spleens harvested, and electrofused into myeloma cells to produce hybridomas secreting Mabs. After unsuccessful efforts to produce noncross-reactive Mabs, mice were inoculated for ascites production of Mabs.
Multiple clones for each protein are being produced for development of a working sandwich ELISA/lateral flow device and subsequent testing of beef and pork products heated to various temperature endpoints. Two frankfurter formulations with no potassium lactate (KL) or 3.3 percent KL were prepared and each batch treated 30 seconds with one of 4 dips: control (saline solution), acidified calcium sulfate with propionic acid (ACSP), 3.3 percent KL or 3.4 percent lactic acid (LA). Samples then were vacuum packaged, stored at 4.5C for 12 weeks and evaluated at 2 week intervals. The addition of KL slightly decreased water activity and percent moisture in franks. Vacuum-package purge was slightly higher in samples treated with ACSP. Descriptive attribute results indicated minimal effects on the sensory properties of the frankfurters containing KL and dipped in antimicrobial solutions. Ground (GR) or desinewed (DS) lamb trimmings were combined with a konjac flour (KF) gel at levels of 0, 10 or
20 percent to produce a low-fat (8 percent) cured sausage. Desinewing reduced collagen content by 2.3 mg/g tissue and cook yield by 0.6 percent when compared to GR trimmings. Grinding increased aerobic plate counts (APC) approximately 0.4 log more than DS, but APCs were not affected by inclusion of KF. Sausages with 20 percent KF lowered cook yield approximately 1 percent and slightly reduced sensory panel and texture values. KF gel incorporated at 10 percent had similar properties to a control low-fat desinewed lamb sausage. KF at 20 percent reduced toughening in low-fat sausage products. Use of a konjac gel as a fat mimetic could reduce total caloric energy by replacing a portion of the meat in a lamb sausage formulation.
Impacts
A Mab sandwich ELISA/lateral flow device to verify that a safe endpoint temperature (EPT) has been achieved is being developed for cooked beef and pork products to enhance the safety of these products. A unique feature of this assay is that the final temperature achieved at the completion of cooking or at any time post cooking, even after frozen storage, can be determined. An ELISA-based EPT test would provide meat processors, institutional food preparation units and the USDA-FSIS with a reliable, rapid diagnostic tool to ensure the destruction of pathogens in cooked meat products. Antimicrobial ingredients such as acidified calcium sulfate with propionic acid (ACSP) or 3.4 percent lactic acid (LA) can be applied to the surface of frankfurters with or without lactate to control the growth of Listeria monocytogenes and ensure the safety of ready-to-eat (RTE) meat products. The application of these GRAS ingredients to frankfurter surfaces showed minimal effects on
sensory and physico-chemical properties of the franks. Thus, effective proven interventions are available that control pathogen growth on RTE meat products without detrimentally affecting sensory characteristics. A konjac gel incorporated at 10 or 20 percent levels can be used as a fat mimetic in low-fat (8 percent) desinewed lamb sausage with only minor changes in product chemical composition, yield, sensory characteristics and textural attributes. Application of this research to existing sausage products could reduce total fat calories and provide healthier meat products for consumers.
Publications
- Osburn, W.N., and Keeton, J.T. 2004. Evaluation of low-fat sausage containing desinewed lamb and konjac gel. Meat Sci. 68:221-233.
- Nunez, de Gonzalez, M.T., Keeton, J.T., Acuff, G.R., Ringer, L.J., and Lucia, L.M. 2004. Effectiveness of acidic calcium sulfate with propionic and lactic acid and lactates as post-processing dipping solutions to control Listeria monocytogenes on frankfurters with or without potassium lactate and stored vacuum packaged at 4.5C. J. Food Protect. 67(5):915-921.
- Nunez, de Gonzalez, M.T., Keeton, J.T., and Ringer, L.J. 2004. Sensory and physico-chemical characteristics of frankfurters containing lactate with antimicrobial surface treatments. J. Food Sci. 69(6):S221-228.
- Chae, S.H., Keeton, J.T. and Smith, S.B. 2004. Conjugated linoleic acid reduces lipid oxidation in aerobically stored, cooked ground beef patties. J. Food Sci. 69(8):S306-309.
- Ricke, S.C., Kundinger, M.M., Miller, D.L., and Keeton, J.T. 2004. Alternatives to antibiotics: Chemical and physical antimicrobial interventions and food-borne pathogen response. Poultry Sci. Accepted.
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Progress 01/01/03 to 12/31/03
Outputs
Ground bovine Semimembranosus muscle was inoculated with E. coli and cooked to one of 24 time/temperature combinations. Bacterial thermal death curves declined logarithmically with increased temperature and cooking times along with a parallel decline in immunologic lactate dehydrogenase 5 (LDH5) reactivity at 61C and above. LDH5 may be suitable for inclusion in a multiple Mab assay to verify cooking endpoint temperatures (EPTs) of beef and pork from 61 to 69C. Infusion of Semimembranosus muscle with 0-3 percent sodium chloride with or without 0.5 percent sodium tripolyphosphate (STPP) increased protein extraction. With incremental heating, a linear decline in total protein occurred. LDH5 immunoblots showed parallel log decreases with increasing temperature, but LDH5 was less reactive in the presence of salt. Reactivity was moderately higher with STPP. Frankfurters containing no potassium lactate (KL) or 3.3 percent KL were surface inoculated (L. monocytogenes
mixture), held 60 min then dipped 30 sec in saline solution, acidified calcium sulfate with propionic acid (ACSP), 3.3 percent KL or 3.4 percent lactic acid (LA). L. monocytogenes was reduced by 5.8 logs on frank surfaces with ACSP and counts remained at the minimum level of detection (1.7 log CFU/frank) over 12 weeks of storage at 4C. Fresh pork sausage with no plum puree, 3 or 6 percent dried plum puree (PP), dried plum/apple puree (DPA) or 0.02 percent butylated hydroxyanisole/ butylated hydroxy toluene (BHA/BHT) were stored at 4C (28 da), or cooked as patties and stored at 4 and -20C (90 da). Six percent PP reduced cooking yields, but 3 or 6 percent PP was as effective as BHA/BHT for retarding lipid oxidation in precooked patties. Patties with 3 percent PP or DPA were as desirable as the control, but patties with 6 percent of either plum product were less desirable. Beef roasts (Semimembranosus, Adductor) were injected (20 percent) with a brine containing 0, 2.5 or 5 percent fresh
plum juice concentrate (FP), dried plum juice concentrate (DP) or spray dried plum powder (PP), cooked (62.8C) and vacuumed slices stored (4C) for 70 da. Plum treatments reduced lipid oxidation (TBA values), but 5 percent DP or PP increased cooking loss. FP or DP could be incorporated into beef roasts at 2.5 percent to reduce lipid oxidation and prevent warmed-over flavor (WOF). Hams were treated similarly, but no differences were noted in lipid oxidation and all plum ingredients increased cooking losses. Inclusion of plum ingredients in cured ham may reduce product yield, have limited antioxidant properties and possibility reduce consumer acceptability. Fresh ground beef patties with no antioxidant, 0.02 percent BHA/BHT, 3 percent DPP or 0.25 percent rosemary extract were irradiated at 0, 1.7 or 2.3 kGy and stored (4C) for 28 da. All antioxidant treatments were effective for retarding irradiation induced lipid oxidation (TBARS values) during storage, but DPP was a less effective than
rosemary extract or BHA/BHT. Irradiation increased lipid oxidation, but no differences were noted between irradiation levels.
Impacts
Surface decontamination of ready-to-eat (RTE) meats is critically important for ensuring food safety and for meeting USDA-FSIS mandated zero tolerance requirements for Listeria monocytogenes on these products. Our laboratory has validated the listericidal and listeristatic effectiveness of GRAS approved acidified calcium sulfate with propionic acid (ACSP) when applied to the surface of frankfurters prior to packaging. Treatment of RTE product surfaces with ACSP may afford an even greater level of safety to consumers and meet the mandated USDA-FSIS zero tolerance requirements. Dried plum products (DPP) have been shown to have exceptionally high antioxidant activity when measured by ORAC values. A series of studies evaluated the antioxidant effectiveness of DPP in precooked pork sausage, roast beef and fresh irradiated ground beef patties. Results from these studies indicate that DPP and plum concentrates have great potential as a new category of natural antioxidants in
some cases being equivalent to BHA/BHT for suppressing lipid oxidation. A multiple Mab immunoassay to predict the endpoint temperature (EPT) achieved in cooked beef and pork products is under development. A unique feature of this assay is that the final temperature at the completion of cooking or at any time post cooking even after frozen storage can be determined. Development of an ELISA-based EPT test would provide meat processors with a reliable HACCP verification tool and the USDA-FSIS with an accurate diagnostic test to ensure the destruction of pathogens.
Publications
- Keeton, J.T. and Kerri B. Harris. 2003. The HACCP System and Importance of Verification Procedures. Chapter 20, in Pre-Harvest and Post-Harvest Food Safety: Contemporary Issues and Future Directions, Ross C. Beier, Suresh D. Pallai, Timothy D. Phillips and Richard L. Ziprin, Editors. Iowa State Press, a Blackwell Publishing Company, Ames, IA.
- Keeton, J.T. and Sarah M. Eddy. 2003. Chemical Methods for Decontamination of Meat and Poultry. Chapter 24, in Pre-Harvest and Post-Harvest Food Safety: Contemporary Issues and Future Directions, Ross C. Beier, Suresh D. Pillai, Timothy D. Phillips and Richard L. Ziprin, Editors. Iowa State Press, a Blackwell Publishing Company, Ames,IA.
- Nunez De Gonzalez, Maryuri Tibisay. 2003. Antimicrobial Effects of Surface Treatments and Ingredients on Cured RTE Meat Products. Ph.D. Dissertation. Texas A&M University, College Station, TX.
- Movileanu, Iulia 2003. Reducing Lipid Oxidation in Irradiated Ground Beef Patties by Natural Antioxidants. M.S. Thesis. Texas A&M University, College Station, TX
- Nunez de Gonzalez, Maryuri T., Keeton, J.T., Acuff, G.R., Ringer, L. J. and Lucia, Lisa M. 2004. Effectiveness of acidic calcium sulfate with propionic and lactic acid and lactates as post-processing dipping solutions to control Listeria monocytogenes on frankfurters with or without potassium lactate and stored vacuum packages at 4.5C. J. Food Protect. Accepted.
- Keeton, J.T. and Sarah M. Eddy. 2003. Chemical and Physical Characteristics of Meat (e) Chemical Composition. In Encyclopedia of Meat Sciences, Werner Jensen, Carrick Devine and Michael Dikeman, Editors. Elsevier Limited, Oxford, UK.
- Miller, D.R., J.T. Keeton, G.R. Acuff, and J.F. Prochaska. 2003. Verification of Cooking endpoint temperatures in beef by immunoassay of lactate dehydrogenase isozyme 5. J. Food Sci. 68(6):2076-2079.
- Miller, D.R., J.T. Keeton, and J.F. Prochaska. 2003. Brine ingredients alter the immunoassay of lactate dehydrogenase isozyme 5 in beef. J. Food Sci. 68(6):2072-2975.
- Morris, C.A., McKenna, D.R., Keeton, J.T., Miller, R.K., Hale, D.S., Harris, S.D. and Savell, J.W. 2003. Consumer acceptability of processed ostrich meat products. J. Muscle Foods 14:173-179.
- Osburn, W.N. and Keeton, J.T. 2003. Utilization of konjac gel and desinewed lamb in low-fat sausage. J. Food Sci. Accepted.
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Progress 01/01/02 to 12/31/02
Outputs
Frankfurters with and without 3.3% KL were surface inoculated with four strains of Listeria monocytogenes, dipped in a saline solution, acidified calcium sulfate (ACS), 3.3% potassium lactate (KL) or 3.4% lactic acid (LA) and stored 12 weeks at 4.5 C to evaluate surface decontamination. L. monocytogenes numbers were reduced by 5.8 logs with ACS and counts remained at the minimum level of detection (1.7 logs) during storage demonstrating the listericidal effect of ACS. LA also reduced L. monocytogenes counts initially, but did not have the residual listericidal and listeristatic effects as ACS. Precooked pork sausage patties, beef roasts and hams were manufactured to contain 2.5 to 6 percent dried plum products (DPP) and evaluated for oxidative stability during storage. Overall, a DPP used at 3 or 6 percent was as effective as BHA/BHT for retarding lipid oxidation in precooked, frozen pork patties. In roast beef, DPP reduced lipid oxidation as measured by
2-thiobarbituric acid (TBARS) values which could potentially minimize warmed-over flavor. No differences in TBARS values were noted for boneless ham. Fresh beef patties made with no antioxidant, 0.02 percent BHA/BHT, 3 percent dried plum puree (DPP) or 0.25 percent rosemary extract were aerobically packed, irradiated at 0, 1.5 or 2 kGy and stored at 5 C. Irradiation increased TBARS values while all antioxidant treatments maintained lower TBARS levels over storage. DPP TBARS values were lower, but not as low as BHA/BHT and rosemary extract. This research indicates that DPP or their extractives could potentially be as effective as BHA/BHT or rosemary extract for inhibiting lipid oxidation in meat products. Five bovine and porcine muscle proteins (LDH5, serum albumin, myoglobin, triose phosphate isomerase and enolase) incrementally lose antigenicity or solubility from when heated from 65 to 79 C. Multiple Mabs against four proteins have been derived from hybridoma cells and screened
against purified forms of their respective proteins. Numerous clones producing Mabs that cross react with bovine and porcine muscle tissue proteins heated to specified endpoints (EPT) are being tested for temperature specificity and loss of antigenicity during heating. It is postulated that by comparing the ratios of respective heated tissue proteins that they can predict the EPT achieved in cooked meat products. A rapid, accurate Mab based device can then be constructed to verify the actual heating EPT achieved even if frozen after cooking. Publication are withheld pending patent application in 2002.
Impacts
Surface decontamination of ready-to-eat (RTE) meats is critically important for ensuring food safety and for meeting USDA-FSIS mandated zero tolerance requirements for Listeria monocytogenes on these products. A study in our laboratory has validated the listericidal and listeristatic effectiveness of acidified calcium sulfate (ACS), a GRAS approved ingredient, when applied to the surface of frankfurters prior to packaging. Thus, treatment of RTE product surfaces with ACS my afford an even greater level of safety to consumers and meet the mandated zero tolerance requirements. Dried plum products had been shown to have exceptionally high antioxidant activity when measured by ORAC values. A series of studies evaluated the antioxidant effectiveness of dried plum products (DPP) in precooked pork patties, roast beef and fresh irradiated ground beef patties. Results from these studies indicate that DPP have great potential as a new category of natural antioxidants being
equivalent to BHA/BHT for suppressing lipid oxidation. A multiple Mab immunoassay to predict the endpoint temperature (EPT) achieved in cooked beef and pork products is under development. A unique feature of this assay is that the final temperature at the completion of cooking or at any time post cooking even after frozen storage can be determined. Development of an ELISA-based EPT test would provide meat processors with a reliable HACCP verification tool and the USDA-FSIS with an accurate diagnostic test to ensure the destruction of pathogens.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
Five, bovine and porcine muscle proteins (lactate dehydrogenase isozyme 5 (LDH5), serum albumin, myoglobin, triose phosphate isomerase and enolase) incrementally lose antigenicity or solubility from 65 to 79C. Specific monoclonal antibodies (Mabs) are being screened from hybridomas for recognition of the heat labile proteins and potential inclusion in a diagnostic testing device to verify attainment of safe heating endpoints in cooked meat products. It is postulated that by comparing the ratios of the respective proteins that they can be used to predict the actual endpoint temperature (EPT) achieved in cooked products to within 1C. Inclusion of NaCl up to 3 percent and alkaline phosphates up to 0.5 percent into bovine and porcine muscle do not appear to significantly change the ratios. Additional screening of individual Mab clones from specific proteins should enable the development of an accurate, rapid, simple and inexpensive testing device for determining the EPT
achieved in meat products even if frozen after cooking. A biomechanical technique developed by Spadaro applied a static compression of 3 percent for 4 min to raw Longissimus dorsi samples (2.54 cm3) harvested 48 hrs post-mortem from cattle known to vary in tenderness. Energy dissipated parallel to fibers of samples accounted for over 73 percent of the variation (R = -.86) in tenderness in comparison to Warner-Bratzler shear force (WBSF) values which accounted for only 62 percent (r = .79) of the variation. This technique provides a more accurate, rapid, less costly and predictable method of measuring raw beef loin tenderness than WBSF. Further development is needed to reduce the measurement time and evaluate the technique's potential for commercial application. Collagen was covalently cross-linked by horseradish peroxidase and hydrogen peroxide catalysis to evaluate the application this polymerization technique to restructured meat products and as a potential prophylactic wound
sealant. A polymerized collagen matrix increased deformation resistance (binding) in restructured meat products and could improve product integrity. One percent NaCl in combination with 0.5 percent sodium tripolyphosphate (STTP) synergistically enhanced the strength of the collagen cross-linking reaction. A new technology has been developed for potentially stabilizing restructured meat products and more importantly enabling the use of purified collagen polymers as non-antigenic wound sealants for surgical or emergency medical use. This polymerized matrix also could be used as a vehicle to deliver timed-release antibiotics, vaccines and growth factors to slow healing wounds. Low-fat bologna (LFBM, 2 percent) with konjac (KB), starch, carrageenan, and soy protein isolate (SPI) substitutions in the meat block formed stable products. Scanning electron micrographs (SEM) showed meat proteins and polysaccharide gums to form separate gels which stabilized the product matrix. LFBM with 1% KB
and 2% SPI had sensory characteristics similar to the control. Combinations of ingredients used to reduce fat were more complementary to product stability and quality than the use of singular ingredients.
Impacts
A multiple antibody immunoassay to predict the endpoint temperature achieved in cooked beef and pork products is under development. A unique feature of this assay is that the final temperature at the completion of cooking or at any time post-cooking even after frozen storage can be determined. Adoption of this ELISA-based test would provide meat processors with a reliable HACCP verification tool and the USDA-FSIS with an accurate diagnostic test to ensure that sufficient heat has been applied to products to destroy pathogens. A biomechanical compressive technique was developed to measure tenderness that accounts for more variation than the Warner-Bratzler shear force (WBSF) device. The technique provides a more accurate, rapid, less costly and predictable method of measuring raw beef tenderness. Subsequent development could lead to an on-line, non-destructive tenderness measurement for raw primal cuts that could be configured into an instrument grading system for the
beef industry and would guarantee tenderness to consumers. A covalently cross-linked collagen polymerization system has been developed. The greatest impact lies in expanding the utilization of soluble and insoluble collagen fractions from avian, bovine and porcine sources to enhance the value of animal by-products. Additional applications for the collagen fractions include edible sausage casings, non-antigenic wound sealants for surgical use and absorbable bandages that could be configured to deliver timed-release antibiotics, vaccines and growth factors to slow healing wounds.
Publications
- Spadaro, V., Boleman, Randi M., Allen, D.H, Keeton, J.T., Moreira, Rosana. 2002. Biomechanical properties of meat and their correlation to tenderness. J. Texture Studies 33 (1). Accepted.
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Progress 01/01/00 to 12/31/00
Outputs
Evaluations of ground beef Semimembranosus muscle samples were done. Aliquots of ground muscle were packed into disposable sterile tubes by centrifugation at 600 x g, then cooked to core endpoint temperatures (EPT) to 0.1 C of the desired EPT from 63 to 73 C at 2 C intervals. After immediate chilling to 4 C, the ground muscle preparations were extracted in 5 volumes (wt/wt) of 0.01M neutral phosphate buffer. Some extracts contained in addition NaCl (1 to 3%) or NaCl plus 0.5% sodium tripolyphosphate (STPP). Clarified sample supernatants were analyzed for total protein content, immunoblot quantification of lactate dehydrogenase isozyme 5 (LDH), bovine serum albumin (BSA) and myoglobin (Myo), as well as by SDS-polyacrylamide gel electrophoresis profiles. Known protein standards were run with all assays for comparison and quantification. Previous results indicated that LDH levels declined with EPT up to 69 C, beyond which this protein was not significantly measurable
either on the gels or the immunoblots. We since have shown that serum albumin and myoglobin exhibit similar declines and similar high levels of variability from sample to sample. Thus, it was concluded that no single one protein examined could provide better than 2 C accuracy for EPT determination, and that each protein has a maximum temperature beyond which it cannot meaningfully be measured. What also became apparent was that different proteins declined with temperature at different rates which were relative to each other, and which remained relative even in the presence of salt/STPP. We developed the premise that, by making simultaneous measurements of three (or more) proteins and expressing their amounts relative to each other (i.e., as a ratio), it should be possible to accurately (1 C) assess the EPT reached. Total soluble protein was measured by the Bradford method. Ratios (M/B/L) calculated by dividing myoglobin by BSA by LDH values x 1000. Both the total soluble protein and
the three individual proteins were significantly variable between samples. But, when the individual protein values are expressed as a ratio rather than absolute values, a rather clear and consistent order-of-magnitude change for each 2 C increment is observed. Use of monoclonal rather than polyclonal antibodies is expected to improve upon these results. Similar preliminary results have been obtained using pork Semimembranosus samples cooked from 65 to 79 C. The addition of salt and/or STPP do not appear to significantly change the end results. Further work on both beef and pork proteins, including development of antibodies to additional promising protein candidates for EPT determination currently are in progress. This work will continue over the next two years through a USDA-NRI grant funded in December 2000.
Impacts
A multiple antibody immunoassay device is being developed to predict the endpoint temperature (1 C) achieved in beef and pork products. The unique advantage of this device is that the EPT achieved could be determined at cooking or at any time post-cooking, even after frozen storage. Development of this ELISA-based "molecular thermometer" would provide meat processors with a HACCP verification tool that also could be used by the USDA-FSIS as a diagnostic test to ensure that sufficient heat has been applied to destroy pathogen contaminants.
Publications
- Chin, Koo Bok, Keeton, J. T., Miller, D. R. 2000. Changes in porcine sarcoplasmic protein fractions from ham muscle as affected by salt, sodium tripolyphosphate and heating endpoint temperatures (EPT). 4607. Annual meeting of the Institute of Food Technologists. June 10-14, Dallas, TX.
- Marburger, R. M., Keeton, J. T., Maddock, R. J. and Moreira, R. G. 2000. Biomechanical characterization of meat tenderness. Annual meeting of the American Meat Science Association. June 18-21, Columbus, OH.
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Progress 01/01/99 to 12/31/99
Outputs
Ground pork ham muscles treated with eight salt (NaCl) and sodium tripolyphosphate (STTP) combinations were cooked to internal temperatures from 65 to 79C in 2C increments. Protein solubility declined with heating up to 67C, regardless of treatment, but remained constant thereafter. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed 12 protein bands in the raw state (22C). Among these, the 63, 50 and 16 kDa proteins disappeared gradually with incremental heating and were barely detectable at 71, 75 and 79C, respectively. These proteins may be useful as potential indicators to determine endpoint cooking temperatures in ground pork muscles. A new biomechanical technique developed by Spadaro applied a static compression of 3 percent for 4 min to raw Longissimus dorsi samples (2.54 cm3) taken from 45 strip loins (IMPS 180) harvested 48 hrs post-mortem from cattle known to vary in tenderness. Biomechanical measurements (energy dissipated parallel
to fibers) of samples accounted for over 73 percent of the variation (R = -.86) in tenderness in comparison to Warner-Bratzler shear force (WBSF) values which accounted for only 62 percent (r = .79) of the variation in tenderness. This technique accounts for more variation in tenderness than WBSF and provides for a more accurate, rapid, less costly and predictable method of measuring raw beef loin tenderness. Experiments covalently cross-linked collagen by a horseradish peroxidase and hydrogen peroxide catalysis mechanism to examine the potential for applying this new technology to restructured meat products and as a wound sealant. Polymerized collagen in gels and prototype restructured meat products increased deformation resistance (binding) and could potentially improve product integrity. Common non-meat ingredients, 1 percent NaCl in combination with 0.5 percent sodium tripolyphosphate (STTP), synergistically enhanced the strength of the collagen cross-linking reaction. A new
collagen cross-linking technology has been developed potentially stabilizing value-added processed meat products. Non-food applications exist for purified collagen polymers such as non-antigenic wound sealants for surgical or emergency medical use that could be configured to deliver timed-release antibiotics and growth factors to slow healing wounds.
Impacts
A new biomechanical technique can predict cooked steak tenderness as determined by sensory panel by simply compressing a raw sample. A multiple antibody immunoassay device is being developed to predict the endpoint temperature (+1C) achieved in beef and pork products any time post-cooking. A new collagen polymerization technique can serve as a meat particle binder and/or wound sealant.
Publications
- Chin, K.B., Keeton, J.T., Longnecker, M.T. and Lamkey, J.W. 1999. Utilization of soy protein and konjac blends in a low-fat bologna (model system). Meat Science 53: 45-57.
- Spadaro, V., Allen, D.H, Keeton, J.T., and Moreira, Rosana. 1999. Biomechanical properties of meat and their correlation to tenderness. J. Food Texture. Accepted.
- Chin, K.B., Keeton, J.T., Longnecker, M.T. and Lamkey, J.W. 1999. Evaluation of konjac blends and soy protein isolate as fat replacements in low-fat bologna. J. Food Science. Accepted.
- Marburger, R. M. Biomechanical Characterization of Meat Tenderness. August 1999. M.S. Thesis. Texas A&M University, College Station, TX.
- Prochaska, J. F., Keeton, J. T., Miller, D. R., and Birkhold, S. G. 1999. Development of cross-linked collagen as a potential binding agent. Paper #4124. Annual meeting of the Institute of Food Technologists. July 24-28, Chicago, IL.
- Prochaska, , J. F., Keeton, J. T., Miller, D. R., and Birkhold, S. G. 1999. Cross-linked collagen as a potential binding agent in restructured meat products. . Paper #4144. Annual meeting of the Institute of Food Technologists. July 24-28, Chicago, IL.
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Progress 01/01/98 to 12/31/98
Outputs
Bovine Semimembranosus was homogenized and treated with salt (1-3 percent), sodium tripolyphosphate (STPP) (0, .5 percent) and cooked at 2C intervals to 73C. Immunoblots of lactate dehydrogenase isozyme 5 (LDH5) noted a linear decline in antigenicity to 69C. Increasing salt decreased LDH5 response, but STPP moderated this decline. STPP increased total extractable protein. SDS-PAGE gels identified 8 proteins that declined in response to heating through USDA specified heating endpoints. These proteins are potential heating endpoint markers for ground beef and beef products. Monoclonal antibodies (Mabs) are being developed for marker proteins. Porcine ham muscles were treated with salt, STPP combinations described above and heated in 2C increments from 65-79C. Three proteins declined incrementally and are potential endpoint temperature markers. Native collagen from calf skin was polymerized by a catalyst to form a gel matrix suitable for cold-set binding of structured
meat products. Catalyst combinations were evaluated and multi-species binding models tested. Tissues dominant in red muscle fibers were more cohesive. Potential exists for development of an in situ, collagen-based wound sealant derived from animal by-products (inedible trimmings, spent hens, skin, sinew, etc.). Low-fat bologna (2 percent) models were formulated with konjac, starch, carrageenan blends. Stable products were formed with .5-1 percent konjac blends with or without soy protein isolate replacing up to 2 percent of the meat protein.
Impacts
(N/A)
Publications
- Lin, K.W. and Keeton, J.T. 1998. Textural and physicochemical properties of low-fat, precooked ground beef patties containing carrageenan and sodium alginate. J. Food Sci. 63:571-574.
- Chin, K.B. Keeton, J.T., Longnecker, M.T., and Lamkey, J.W. 1998. Functional, textural and microstructural properties of low-fat bologna model system formulated with a konjac blend. J. Food Sci. 63:801-807.
- Chin, K.B., Keeton, J.T., Longnecker, M.T., and Lamkey, J.W. 1998. Low-fat bologna in a model system with varying types and levels of konjac blends. J. Food Sci. 63:808-813.
- Prochaska, J.F., Ricke, S.C., and Keeton, J.T. 1998. Meat Fermentation: Research Opportunities for the Future. Food Technol. 52:52-59.
- Chin, K.B., Keeton, J.T., Longnecker, M.T. and Lamkey, J.W. 1998. Utilization of soy protein and konjac blends in a low-fat bologna model system. Meat Science. Accepted for publication.
- Prochaska, J.F. Development of Cross-Linked Collagen as a Binding Agent for Restructured Meat Products. December 1998. Texas A&M University, College Station, TX.
- Chin, K.B., Keeton, J.T., Lamkey, J.W., and Longnecker, M.T. 1998. Evaluation of konjac blends and soy protein isolate as fat replacements in low-fat bologna. Abstract. Institute of Food Technologists, Atlanta, GA. June 21 to 24.
- Chin, K.B., Keeton, J.T., Lamkey, J.W. and Longnecker, M.T. 1998. Evaluation of konjac blends and soy protein isolate as fat replacements in low fat bologna. Abstract. American Meat Science Association Graduate Student Research Paper Competition, Ph.D. Division. Storrs, CN, June 28 to July 1. Third place award.
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Progress 01/01/97 to 12/31/97
Outputs
Ground bovine Semimembranosus muscle was inoculated with rifampicin resistant E. coli and left raw or cooked to one of 24 time/temperature combinations. Bacterial thermal death curves exhibited a consistent log decline with increasing temperature and cooking times at a given temperature which paralleled decreases in lactate dehydrogenase 5 (LDH5) antigenicity at 61C and above. Total protein exhibited a linear time/temperature decline. Based on immunologic analysis LDH5 appears suitable for development into a rapid assay method for verification of cooked beef endpoint temperatures (EPT) above 61C. Semimembranosus extracts containing NaCl (0-3%) with/without 0.5% sodium tripolyphosphate (STPP) were cooked 58-65C. About 50% more protein was solubilized and linear declines in LDH5 immunoblots were moderated by STPP. Presence of STPP in brine ingredients enhanced LDH5 antigenicity. Low-fat bologna (<2%) models (LFBM) were formulated with 0.5-1% konjac blends (KB) with or
without 2% soy protein isolate (SPI). Scanning electron micrographs (SEM) of LFBM showed meat proteins and polysaccharide gums to form separate gels which stabilized the product matrix. Low-fat bologna with 1% KB and 2% SPI had sensory characteristics similar to the control and 2% SPI replacement of the meat block reduced formulation costs over KB alone.
Impacts
(N/A)
Publications
- STALDER, J. W., SMITH, G. L., KEETON, J. T., and SMITH, S.B. 1997. Lactate dehydrogenase activity as an endpoint heating indicator in cooked beef. J. Food Sci. 62(2):316-320.
- CHIN, K.B., KEETON, J.T., LONGNECKER, M.T., and LAMKEY, J.W. 1997. Characterization of low-fat bologna in a model system with varying types and levels of konjac blends. J. Food Sci. Accepted for publication.
- CHIN, K.B. KEETON, J.T., LONGNECKER, M.T., and LAMKEY, J.W. 1997. Functional, textural and microstructural properties of low-fat bologna (model system) formulated with a konjac blend. J. Food Sci. Accepted for publication.
- KOO BOK CHIN. 1997. Evaluation of Konjac Blends, Soy Protein Isolate and Lean Muscle as Fat Replacements in Low-fat Meat Batters. Ph.D. Dissertation. August 1997. Texas A&M University, College Station.
- Fundamentals of Food Microbiology. 1997. Fermented Foods and Beverages -- Meat and Fish by S. B. Ricke and J. T. Keeton. Ch. VIII. Section 34. Mike Doyle, Tom Montville and Larry Beuchat, Eds. American Society of Microbiology, 42 Chs., approx. 800 pp. Chapter accepted April 1996, published 1997.
- POLLOCK, K.D., HALE, D.S., MILLER, R.K., ANGEL, R., BLUE-MCLENDON, A. BALTMANIS, B. and KEETON, J.T. 1997. Ostrich Slaughter and By-Product Yields. American Ostrich Association, Fort Worth, Texas. April 1997. pp. 31-35.
- POLLOCK, K.D., HALE, D.S., MILLER, R.K., ANGEL, R., BLUE-MCLENDON, A. BALTMANIS, B. and KEETON, J.T. 1997. Ostrich Carcass and Meat Yields. American Ostrich Association, Fort Worth, TX. April 1997. pp. 36-38.
- POLLOCK, K.D., HALE, D.S., HERBER-MCNEILL, S., MILLER, R.K., ANGEL, R., BLUE-MCLENDON, A. BALTMANIS, B. and KEETON, J.T. 1997. The Nutritional Profile of Cooked and Raw Ostrich Meat. American Ostrich Association, Fort Worth, TX. April 1997. pp. 39-45.
- POLLOCK, K.D., MILLER, R.K., HALE, D.S., ANGEL, R., BLUE-MCLENDON, A. BALTMANIS, B., KEETON, J.T. and MACA, J.V. 1997. Quality of Ostrich Steaks as Affected by Vacuum-Package Storage, Retail Display and Differences in Animal Feeding Regimen. American Ostrich Association, Fort Worth, TX. April 1997. pp. 46-53.
- CHIN, KOO-BOK and KEETON, J.T. 1997. Functional Properties of Ostrich Muscle as Influenced by Diet and Post-mortem Storage. American Ostrich Association, Fort Worth, TX. April 1997. p. 54.
- CHIN, K.B. and KEETON, J.T. 1997. Functional, textural and microstructural properties of low-fat bologna formulated with a konjac blend. Institute of Food Technologists, Orlando, FL. June 14-18, 1997.
- CHIN, K.B. and KEETON, J.T. 1997. Characterization of low-fat bologna with varying levels of konjac blends and moisture:protein ratios. Institute of Food Technologists, Orlando, FL. June 14-18, 1997.
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Progress 01/01/95 to 12/30/95
Outputs
Polyclonal antibodies (pab) for bovine lactate dehydrogenase (LDH) were used to detect loss of LDH antigenicity by immunoblot analysis in cooked beef over the temperature range of 60 deg. -62 deg. C. Results indicate that bovine LDH Pab may be used as a detector of the USDA cooking endpoint temperature minimum in beef roasts containing typical levels of sodium tripolyphosphate and sodium chloride. Cohesiveness of extruded, sliced hamburger patties from two manufacturers was studied in relation to cooking performance. Tensile determinations with an Instron Universal Testing machine, light micrographs and environmental scanning electron micrographs (ESEM) differentiated structural characteristics of cohesiveness and could serve as in-plant monitoring device to ensure consistency and predict failure of products. Konjac/starch (KS) and konjac/carrageenan (KC) were incorporated into low fat (-3%) bologna formulations as fat replacements at 10 or 20% levels. Meats blocks
(MB) of 65 and 70% were tested and 3 or 30% (3C, 30C) fat controls compared to treatments. 70 MB samples were harder, more rigid, springier and more cohesive than 30C. KC tended to be slightly softer, less springy, less hard and more easily deformed than 3C. Bologna with KS or KC was more similar to 3C than 30C for most traits, served as a functional fat mimic and could be used to reduce caloric density of meat "emulsion" products.
Impacts
(N/A)
Publications
- KEETON, J.T. and MORRIS, C.A. 1995. Carcoplasmic enzymes as potential indicatorsof heating endpoints in meat products. J. Muscle Foods. Accepted.
- MORRIS, C.A., HAYNES, K. C., KEETON, J.T. and GATLIN, D.M. 1995. Fish oil dietaryeffects on fatty acid composition and flavor of channel catfish. J.Food Sci. Accepted.
- MORRIS, C.A., HARRIS, S.D., JACKSON, T.C., MAY, S.G., HALE, D.S., MILLER, R.K., KEETON, J.T., ACUFF, G. R., LUCIA, L.M. and SAVELL, J.W. 1995. Ostrich slaughter and fabrication: 1. Slaughter yields of carcasses and effects of electrical stimMORRIS, C.
- A., HARRIS, S.D., MAY, S.G., MILLER, R. K., KEETON, J.T. and SAVELL, J.W. 1995. Ostrich slaughter and fabrication 2: Carcass weights, fabrication yields, and muscle color. Poult.Sci. In press.
- CHIN, K. B., KEETON, J.T. and LACEY, R.E. 1995. Reduction of drying time for pepperoni by vacuum-drying. J.Food Sci. Accepted.
- SPADARO, V., and KEETON, J.T. 1996. Qualitative and quantitative textural assessment of cooked ground beef patties. J. Food Sci. Accepted.
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Progress 01/01/94 to 12/30/94
Outputs
Bovine lactate dehydrogenase (LDH) was identified as an enzyme which is heat inactivated at 62(degree)-63(degree) C, a minimum temperature required by the USDA-FSIS for pre-cooked roast beef. Polyclonal antibodies specific for the active form of LDH (isozyme 5) are being evaluated for potential incorporation into an ELISA assay and subsequent development as an end point temperature verification test for pre cooked beef products. Six different temperature and vacuum combinations were evaluated to determine their effectiveness for drying pepperoni. Pepperoni dried under full vacuum at 19(degree) to 22(degree) C achieved a M:P ratio of 1.6:1 in 9 to 12 days as compared to a conventional drying period of 15 to 18 days, thus reducing drying time by approximately 30%. Two types of konjac flour at 10 or 20% of the total batch formulation were incorporated into bologna which contained either a 65 or 70% meat block. Analyses being performed are product yield, pH, water holding
capacity, proximate analysis, Instron textural measurements, sensory panel evaluation, Hunter color values and formulation cost analysis. Microbiological storage-life over a 60 day period is also being evaluated. Formulation of bologna with varying degrees of konjac gel will determine the functional characteristics, sensory properties and economic potential for glucomannan-based products.
Impacts
(N/A)
Publications
- CHIN, K. B., KEETON, J. T. and LACEY, R. E. 1994. Evaluation of vacuum-drying for reduction of fermented sausage drying time. Abstract submitted to the Institute of Food Technologists.
- KEETON, J. T. 1994. Low-fat meat products --Technological problems with processing. Meat Science 36: 261-276.
- LIN, K. W. and KEETON, J. T. 1994. Determination of optimum particle size for low-fat, precooked ground beef patties. J. Muscle Foods 5:63-76.
- OSBURN, W. N. and KEETON, J. T. 1994. Utilization of konjac flour gel as a fat substitute in low-fat prerigor pork sausage. J. Food Sci. 59:484-489.
- KRAHL, L. M., RHEE, K. S., LIN, K. W., KEETON, J. T. and ZIPRIN, Y. A. 1994. Sodium lactate and sodium tripolyphosphate effects on oxidative stability and sensory properties of precooked low-fat sausage with carrageenan. J. Muscle Foods.
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Progress 01/01/93 to 12/30/93
Outputs
Twenty-six endogenous enzymes from turkey Pectoralis major and Sartorius muscle taken 24-72 hours postmortem were evaluated for total activity. Six enzyme extracts were tested for loss of activity between 67(degree)-73(degree)C at 2(degree)C increments and heating rates of 0.25, 0.5 or 0.1(degree)C/min. Lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) activity in fresh and frozen turkey Pectoralis major showed consistent declines between 69(degree) and 73(degree)C and might serve as heating endpoint indicators. Low-fat (10%) beef patties varying in particle size by grinding, flaking or a combination of each were precooked, frozen and microwave reheated. Results indicate that patty processors should use a flaking/grinding combination to manufacture low-fat, precooked beef patties destined for microwave reheating to optimize yield and textural properties. Beef patties (10% fat) containing alginate, carrageenan or a combination of each were precooked, frozen and
reheated in a microwave. Patties with the alginate/carrageenan combination were superior to regular ground beef patties (20% fat) in terms of yield and textural properties. Low-fat (10%) prerigor pork sausages containing a konjac gel at 0, 10 or 20% levels were compared to a 40% fat control. Sausages with konjac had equal or improved cooked yields, favorable sensory attributes and slightly higher shear force values (kg/g), but were slightly less juicy.
Impacts
(N/A)
Publications
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Progress 01/01/92 to 12/30/92
Outputs
Twenty-four enzyme activities were evaluated from two types of bovine, porcine and avian muscles to identify muscle tissue enzymes which lose activity at or near minimum heating endpoints required for the major categories of processed meats. Four bovine, six porcine and seven avian enzymes underwent rapid denaturation between 60(degree)-72(degree), 68.8(degree) and 66(degree)-74(degree), respectively, when monitored at 2(degree)C intervals. Species differences were noted for some enzymes. Further study could result in rapid, ELISA based endpoint monitors for ensuring safe cook levels. Seventeen starches and six gums were tested in precooked beef clod roasts to evaluate sensory quality of microwave reheated products. Incorporation of a starch (1.0%), algin gum (0.025%) or a starch 65%/gum 35% combination enhanced cook yields and sensory characteristics of precooked beef reheated in the microwave. Low-fat (10%) prerigor pork sausage patties were manufactured with 0, 10
or 20% Konjac flour and compared to a 40% fat control. Treatment sausages were slightly higher in shear force, most textural attributes, but slightly lower in juiciness. Konjac had no effect on pH, lipid oxidation or microbial growth.
Impacts
(N/A)
Publications
- OSBURN, W.N. 1992. Evaluation of physical, chemical, sensory and microbial characteristics of low-fat precooked lamb and fresh pork sausages made with Konjac flour. M.S. Thesis, Texas A&M University, College Station.
- OSBURN, W. N. and KEETON, J.T. 1992. Utilization of konjac flour as a fat substitute in low-fat prerigor fresh pork sausage. American Meat Science Association. 45th Annual Reciprocal Meat conference. Ft. Collins, CO. Proceedings in publ.
- KEETON, J.T. 1992. Low-fat meat products - technological problems with processing. Proceedings of the International Congress of Meat Science and Technology. Vol. 1, August 23-28. Clermont-Ferrand, France. 175-182 pp.
- KEETON, J.T. 1991. Altering fat composition of red meat and fish products. Food Fats and Health. CAST Task Force Report No. 118. December 1991. 42-51 pp.
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