Progress 01/01/06 to 12/31/06
Outputs
Progress on this project during the past year primarily focused on measuring permeability, hydraulic conductivity, and lipidic conductivity of group beef patties subjected to various cooking treatments. Porosity, pore-size distributions, and effective permeability of water through the ground beef matrix were determined as a function of endpoint temperature and initial fat content. Low fat (5.47%) and high fat (14.45%) ground beef samples were formed into patties and cooked in a moist-air convection oven (Tdry bulb of 176.7degC and Tdewpoint of 93.9degC) to center temperatures of 45, 60, and 75degC. These samples were then analyzed at room temperature for pore-size distributions and permeability, using a liquid extrusion porosimeter and permeameter, respectively. The viscosity and density of beef fat was determined with respect to temperature (40, 50, 60, and 70degC). The median pore diameters increased (P<0.05) with temperature. The permeability
of low fat samples (2.85 x10-14 to 1.53 x10-13 m2) was higher than that of the high fat samples (7.19 x 10-15 to 9.21 x10-15 m2) for all cooking treatments. The highest permeabilities were found for low fat samples cooked to 75degC. The viscosity of beef fat decreased with temperature from 34.25 cP at 40degC to 14.36 cP at 70oC. The hydraulic conductivity, the lipidic conductivity, and the tortuosity of the ground beef matrix were also calculated. Hydraulic and lipid conductivity were greater for low fat samples, compared to the high fat samples, and tended to increase with temperature. Experimental determination of the relative permeability of fat was attempted, but has not been achieved; difficulties have been attributed to deviations from the simplified model for capillary flow and the actual complexity of the meat matrix.
Impacts
It is anticipated that the basic mass transfer properties that are quantified in this project will enable an improved cooking model that will help processors to enact closer tolerances in process design and operation, and thereby improve processing yields and economic returns for fully-cooked, ready-to-eat meat and poultry products.
Publications
- Bornhorst, G.M., Marks, B.P., Orta-Ramirez, A. 2006. Modeling the kinetics of thermally-induced shrinkage of beef muscle during cooking. IFT Abstract 039I-07. Presented at the Institute of Food Technologists Annual Meeting. Orlando, FL. June, 2006.
- Tripuraneni, M.C. 2006. Fat transport properties and mechanisms during cooking of ground meat. M.S. thesis. Michigan State University. East Lansing, MI.
- Tripuraneni, M., Marks, B.P. 2006. Pore-size distributions in whole muscle and ground meat cooked to different endpoint temperatures. IFT Abstract 078D-40. Presented at the Institute of Food Technologists Annual Meeting. Orlando, FL. June, 2006.
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Progress 09/01/03 to 08/31/06
Outputs
OUTPUTS: This project consisted primarily of laboratory-scale experiments and data analysis quantifying the impact of thermal treatment on: (1) fat holding capacity of ground beef, pork, and turkey (2) pore size distribution in ground beef, (3) effective and relative permeability of water and fat through ground beef, and (4) the shrinkage of whole-muscle beef tissue and the associated loss of water. FAT HOLDING CAPACITY: Laboratory experiments were conducted to determine the fat holding capacity of ground beef as a function of temperature and initial fat content, and a mathematical model was developed to describe those data. Additionally, laboratory-scale, moist-air convection cooking tests were conducted to confirm the importance of fat transport across different product species. PORE SIZE DISTRIBUTION: The porosity and pore size distribution within various samples subjected to cooking treatments were determined using a liquid extrusion porosimeter. Whole-muscle samples (beef,
turkey, and pork: 25x25x15 mm3 blocks) and ground beef samples (5 and 15% fat, patties of 35 mm diameter and 10 mm thickness) were tested. The whole-muscle samples were tested raw, and ground beef samples were tested raw and after being cooked to center temperatures of 45, 60, and 75degC in a convection oven (177degC dry bulb, and 94degC dewpoint). PERMEABILITY: Subsequently, permeability, hydraulic conductivity, and lipidic conductivity were measured for ground beef patties subjected to various cooking treatments. Porosity, pore-size distributions, and effective permeability of water through the ground beef matrix were determined as a function of endpoint temperature and initial fat content. Low fat (5.5%) and high fat (14.4%) ground beef samples were formed into patties and cooked in a moist-air convection oven (dry bulb of 176.7degC and dewpoint of 93.9degC) to center temperatures of 45, 60, and 75degC. These samples were then analyzed at room temperature for pore-size
distributions and permeability, using a liquid extrusion porosimeter and permeameter, respectively. The viscosity and density of beef fat was determined with respect to temperature (40, 50, 60, and 70degC). The hydraulic conductivity, the lipidic conductivity, and the tortuosity of the ground beef matrix were also calculated. Experimental determination of the relative permeability of fat was attempted, but has not been achieved; difficulties have been attributed to deviations from the simplified model for capillary flow and the actual complexity of the meat matrix. THERMALLY-INDUCED SHRINKAGE: Lastly, beef round muscle samples (2x10x40 mm) were heated isothermally in temperature-controlled baths of mineral oil at temperatures of 55, 60, 65, or 70degC (234 total measurements). The length, width, thickness, mass, and moisture and fat contents were measured before and after treatment. The normalized length was modeled via an nth-order kinetic model. DISSEMINATION: The primary means of
disseminating the results of this project were scientific abstracts, presentations, a thesis, and journal articles. Several journal articles are not yet in press, but should be published within the next year.
PARTICIPANTS: Dr. Bradley Marks was the project director and supervised all of the Michigan State University (MSU) personnel who worked on this project, including oversight of experimental designs, execution, analysis, and reporting. Adam Watkins completed a Ph.D. in biosystems engineering at MSU, partially supported by this project, and conducted the initial tests on fat holding capacity and species effects on oven cooking yield. Mitra Triparaneni completed an M.S. degree in biosystems engineering at MSU as part of this project and was principally responsible for carrying out the porosimetry and permeability work. Gail Bornhorst was an undergraduate student at MSU who carried out the thermally-induced shrinkage work, including authoring an IFT abstract and a manuscript that has been submitted to a peer-reviewed journal. Dr. Alicia Orta-Ramirez was a research assistant professor at MSU who supervised the laboratory experiments at MSU, including sample acquisition and analyses. Dr.
Nicki Engeseth was the collaborator at the University of Illinois, and supervised the work there on fat chemistry/properties, conducted by a post-doctoral research associate.
TARGET AUDIENCES: The target audience for this project was food process modelers and professionals responsible for process design and analysis, related to ready-to-eat meat and poultry products.
Impacts
This project resulted in new knowledge about the effect of meat species and thermal treatment on the fat holding capacity, mass transport properties, and shrinkage of meat products. Species and initial fat content significantly affected (P<0.05) cooking time, yield, and fat loss for ground beef, pork, and turkey, and fat transport was responsible for up to 28% yield loss for the high fat products. The porosimetry work showed that the median pore diameters within the meat products were significantly (P<0.05) affected by the species, structure (whole-muscle vs. ground), fat content, and endpoint center temperature. Turkey and pork samples had narrow pore size distributions with high porosities (13%), but beef samples had broader pore size distributions with low porosity (5%). All ground beef samples had broader pore size distributions than did the whole-muscle samples, with median pore diameter increasing 70% from raw to fully cooked (75degC). These results indicate that
the pore size distributions are clearly affected by temperature. Therefore, pore diameters and their distributions play a significant role in the complex process of meat patty cooking. Knowledge of these properties is the basis for developing better cooking models to ensure safety and quality of ready-to-eat products. The tests of product permeability revealed that the permeability of low fat ground beef samples (2.8E-14 to 1.5 x10E-13 m2) was higher than that of the high fat samples (7.2 x 10E-15 to 9.2 x10E-15 m2) for all cooking treatments. The highest permeabilities were found for low fat samples cooked to 75degC. Hydraulic and lipid conductivity were greater for low fat samples, compared to the high fat samples, and tended to increase with temperature. Experimental determination of the relative permeability of fat was attempted, but has not been achieved; difficulties have been attributed to deviations from the simplified model for capillary flow and the actual complexity of the
meat matrix. In testing the thermally-induced shrinkage of thin sections of whole-muscle beef, sample length decreased with time (P < 0.0001). The normalized length was modeled via an nth-order kinetic model, with n values ranging from 15 to 50. The results suggested that beef product shrinkage can be modeled as function of both temperature and time; however, the relationship between temperature and the model parameters was not simple, reflecting the complexity of the thermally-induced transitions in the mixed protein matrix. It is anticipated that the basic mass transfer properties and shrinkage models that were quantified in this project will enable an improved cooking model that will help processors to enact closer tolerances in process design and operation, and thereby improve processing yields and economic returns for fully-cooked, ready-to-eat meat and poultry products.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
Work on this project during the past year has focused primarily on quantifying the changes in the fundamental mass transport properties of meat products during cooking. The porosity and pore size distribution within various samples were determined using a liquid extrusion porosimeter. Whole-muscle samples (beef, turkey, and pork: 25x25x15 mm3 blocks) and ground beef samples (5 and 15% fat, patties of 35 mm diameter and 10 mm thickness) were used. The whole-muscle samples were tested raw, and ground beef samples were tested raw and after being cooked to center temperatures of 45, 60, and 75degC (5 replicates) in a convection oven (177degC dry bulb, and 94degC dewpoint). The median pore diameters were significantly (P<0.05) affected by the species, structure (whole-muscle vs. ground), fat content, and endpoint center temperature. Turkey and pork samples had narrow pore size distributions with high porosities (13%), but beef samples had broader pore size distributions
with low porosity (5%). All ground beef samples had broader pore size distributions than did the whole-muscle samples, with median pore diameter increasing 70% from raw to fully cooked (75degC). These results indicate that the pore size distributions are clearly affected by temperature. Therefore, pore diameters and their distributions play a significant role in the complex process of meat patty cooking. Knowledge of these properties is the basis for developing better cooking models to ensure safety and quality of ready-to-eat products. In the coming year, the relative permeability of water and fat through meat products will be measured, and the effects of temperature will be quantified.
Impacts
It is anticipated that the basic mass transfer properties that are quantified in this project will enable an improved cooking model that will help processors to enact closer tolerances in process design and operation, and thereby improve processing yields and economic returns for fully-cooked, ready-to-eat meat and poultry products.
Publications
- Tripuraneni, M., Marks, B.P., and Watkins, A.E. 2005. Fat holding capacity of ground beef during cooking. IFT Abstract 89F-18. Presented at the Institute of Food Technologists Annual Meeting. New Orleans, LA. July, 2005.
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Progress 01/01/04 to 12/31/04
Outputs
Several preliminary tests have been conducted to quantify the impact of fat transport on cooking yield of ready-to-eat meat and poultry products. Laboratory experiments were conducted to determine the fat holding capacity of ground beef as a function of temperature and initial fat content. Fat holding capacities ranged from 0.05 to 0.6 g fat/g nonfat dry matter, and a mathematical model was developed to describe those data. Additionally, laboratory-scale, moist-air convection cooking tests were conducted to confirm the importance of fat transport across different product species. Species and initial fat content significantly affected (P<0.05) cooking time, yield, and fat loss for ground beef, pork, and turkey. The heating time required to reach 85 deg C center temperature varied by as much as 217 seconds between different fat contents of the same species. Differences in cooking yield of up to 18% were measured between different fat contents. Fat transport was
responsible for up to 28% yield loss in the high fat products. After these preliminary tests, current activities are focused on quantifying the fundamental physical and chemical properties and changes in the protein matrix and fat during cooking. The pore size distribution in meat patties, as a function of cooking history, is being tested via a mercury porosimeter. The rheological characteristics of the fat components found in ground meat products are being quantified as a function of thermal history. In the coming year, the focus will be on characterizing the thermal properties of fat in meat products, and integrating the basic physical data (e.g., pore size distributions, fat viscosity) into a mathematical model for fat transport inside the product during cooking.
Impacts
It is anticipated that the improved cooking model that will be generated in this project will enable processors to enact closer tolerances in process design and operation, and thereby improve processing yields and economic returns for fully-cooked, ready-to-eat meat and poultry products.
Publications
- Watkins, A.E., Marks, B.P., Booren, A.M., Ryser, E.T., Orta-Ramirez, A. 2004. A model for predicting yield, temperature profile, and Salmonella inactivation during moist-air impingement cooking of ground beef patties. Institute of Food Technologists Abstract 17H-10.
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