R. PAUL SINGH, Professor

Ph.D., Agricultural Engineering, Michigan State University, 1974
Department of Biological and Agricultural Engineering / Food Science and Technology
2042 Bainer Hall
Phone: 530-752-0811
Email: rpsingh@ucdavis.edu
Web: http://www.rpaulsingh.com

Current Research

Professor Singh's research focuses on studying heat and mass transfer in foods during processing. He and his students investigate the role of different rates of heat/mass transfer in modifying structural and functional properties of foods. Their approach often involves studying different food processes by first developing predictive models that are based on transport phenomena, then collecting data on food properties that are most relevant to a given process. These models are then used to determine the sensitivity of a process to various processing variables.

Frying of foods in oil is a common process used in the snack food industry, yet few studies have been conducted that delineate the physical mechanisms important to heat transfer and oil uptake by foods during frying. Professor Singh and his students have developed predictive models of the frying process that provide new insights on how heat transfers from oil into an immersed food. During frying, several chemical changes take place in a food, such as gelatinization of starch. They have examined the kinetics of starch gelatinization and formation of resistant starch, and determined how the mechanical properties of foods are altered due to these chemical changes. An important sensory attribute of fried foods is crispiness. They have studied the glass transition phenomenon in starchy foods during the frying process. They have measured changes in oil properties during frying. This information has resulted in developing sensors that can be used to monitor oil degradation.

Professor Singh's research group has studied the food safety issues in cooking hamburger patties. Survival of E. Coli O157:H7 in undercooked hamburger patties is a major concern to the food industry. The non-uniform nature of hamburger meat complicates the problem of predicting heat transfer. His studies have involved measuring various properties of the hamburger meat and studying rates of heat transfer when the patties are cooked on a commercial grill. Predictive models of heat transfer have been developed to improve design of industrial grills and develop cooking processes that will assure a safe product without overcooking. Optimization of the cooking process has been done by considering the microbial safety, rate of heat and mass transfer, and textural quality of the hamburger patty.

During the past two years, Professor Singh has begun studies on air impingement systems used in food processing. Heat transfer and fluid mechanics in air impingement jets and their interaction with food are being studied with applications to freezing and thawing phenomena.

A new research program initiated in January 2003 is focused on developing a multi purpose fruit and vegetable processing system for future manned missions to Mars. This research supported by NASA is aimed at developing equipment that will operate under hypogravity conditions and other constraints relevant to space applications. A first version of this equipment will be built by the end of 2003 for testing and evaluation.

Representative Recent Publications

Singh, R. P. 2000. Moving boundaries in food engineering. Food Technology 54(2):44-53.

Singh, R. P., and D. R. Heldman. 2001. Introduction to Food Engineering. Third Edition, Academic Press, London.

Zorrilla, S. E., J. R. Banga, and R. P. Singh. 2003. Dynamic optimization of double-sided cooking of meat patties. Journal of Food Engineering 58:173-182.

Anderson, B. A., A. Sarkar, J. F. Thompson, and R. P. Singh. 2004. Commercial-scale forced-air cooling of packaged strawberries. Transactions of the ASAE (American Society of Agricultural Engineering) 47(1):183-290.

Singh, R. P., and F. Erdogdu. 2004. Virtual Experiments in Food Processing. RAR Press, Davis, California.

Wang, L., and R. P. Singh. 2004. Finite element modeling and sensitivity analysis of double-sided contact-heating of initially frozen hamburger patty. Transactions of the ASAE (American Society of Agricultural Engineers) 47(1):147-157.

Sarkar, A., and R. P. Singh. 2004. Air impingement heating. InImproving the Thermal Processing of Foods, edited by P. Richardson. Chapter 13, pp. 253-276

Sarkar, A., and R. P. Singh. 2004. Modeling flow and heat transfer during freezing of foods in forced airstreams. Journal of Food Science 69(9):488-496.

Membership in Professional Socities

American Society of Agricultural Engineers
Institute of Food Technologists
American Society of Engineering Education

Courses Offered

FST 110B - Heat and Mass Transfer in Food Processing
ABT 110L - Experiments in Food Engineering
EBS 132 - Unit Operations in Biological and Food Engineering
EBS 235 - Advanced Analysis of Unit Operations in Food and Biological Engineering
FST 151 - Food Freezing

Research Support

NASA
USDA (National Research Initiative Program)
USDA (Higher Education Challenge Grant Program)
Grants from food industries in the US and overseas