MICHAEL J. McCARTHY, Professor
Ph.D., Chemical Engineering, University of California, Berkeley, 1986
Department of Food Science and Technology / Biological and Agricultural Engineering
231 Cruess Hall
Phone: 530-752-8921
Fax: 530-752-4759
Email: mjmccarthy@ucdavis.edu
Current Research
Professor McCarthy’s research program is focused on developing and utilizing nuclear magnetic resonance and ultrasonic tomographic techniques to determine the physical and transport properties of food systems and consumer products. Magnetic resonance imaging and ultrasonics are capable of rapidly characterizing material properties as well as for use as process analytical instruments. These technologies are applied to both fresh produce and processed foods.
Fresh Produce:
Internal disorders in fresh fruits and vegetables result in significant losses to growers, packers, sellers and consumers. We have been developing NMR/MRI as an in-line sensor for detecting defects and measuring the quality of fruits and vegetables. The development of a nondestructive sensor would be beneficial to packinghouses, as it would facilitate testing of representative samples or sorting of entire lots of apples and other agricultural products before marketing or further storage. We have designed and built a new portable scanner for use in the field and packing house.
Process dynamics/structure of heterogeneous systems:
We apply MRI to study the structure and dynamics of foods and other heterogeneous materials during and after processing. This work includes the study of material structure and the influence of processing on material structure. Understanding of the material structure and material-process interactions permits better use of products and the setting of guidelines for use, such as cooking time for pasta and the relationship to texture degradation on an institutional steam table.
Viscometry:
In the application of MRI as a viscometer, MRI measurements of the fluid velocity profile in tube flow are coupled with a pressure drop measurement to yield shear viscosity. The range of shear rates for a measurement is set by the fluid flow rate and tube geometry, and ranges from zero at the tube center to a maximum at the tube wall (typically two to three orders of magnitude). Thus, each measurement yields a range of shear viscosity data for a single flow rate, as compared to most conventional viscometers that produce only one data point under the same circumstances. This technique has the potential to significantly enhance process control of industrial processes. Recent work has focused on comparison of ultrasonics to MRI determined viscosity data, understanding of the impact of velocity fluctuations on MRI flow imaging data, and application of ultrasonics.
Development of instrumentation:
Since my appointment at UC Davis, I have applied magnetic resonance to a wide variety of industrial problems. We have been successful at demonstrating the utility of the technique and the unique features of magnetic resonance in relationship to other sensor systems. Unfortunately, the extension of the technique into the "industrial" world has been limited since appropriate instrumentation is not available. This has resulted in developing a program to build microscale NMR sensors using micromachining techniques.
Representative Recent Publications
Walton, J. H., J. S. de Ropp, M. V. Shutov, A. G. Goloshevsky, M. J. McCarthy, R. L. Smith, and S. D. Collins. 2003. A micromachined double-tuned NMR microprobe. Analytical Chemistry 75(19):5030-5036.
Wang, L., K. L. McCarthy, and M. J. McCarthy. 2004. Effect of a temperature gradient on ultrasonic Doppler velocimetry measurement during pipe flow. Food Research International 37(6):633-642.
Uludag, Y., R. L. Powell, and M. J. McCarthy. 2004. Effects of periodic flow fluctuations on magnetic resonance flow images. AIChE (American Institute of Chemical Engineers) Journal 50(8):1662-1671.
M. J. McCarthy, J. H. Walton, J. S. de Ropp, S. D. Collins, M. V. Shutov, and A. G. Goloshevsky. 2004. Development of microscale NMR sensors for control of food processing. Food Sci. Biotechnol. 13(6):848-851.
Goloshevsky, A. G., J. H. Walton, M. V. Shutov, J. S. de Ropp, S. D.Collins, and M. J. McCarthy. 2005. Integration of biaxial planar gradient coils and an RF microcoil for NMR flow. Imaging Meas. Sci. Technol. 16:505-512.
Membership in Professional Societies
American Society of Agricultural Engineers
Institute of Food Technologists
American Institute of Chemical Engineers
The Groupment Ampère
Courses Offered
FST 110A - Physical Principles in Food Processing
FST 203 - Food Processing
EBS 239 - Magnetic Resonance Imaging in Biological Systems
Research Support
The Center for Process Analytical Chemistry
Citrus Research Board
United States Department of Agriculture
National Science Foundation