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JOHN COUPLAND

Assistant Professor of Food Science;
Chair of the Ingredients as Materials Impact Group

103 Borland Laboratory
University Park, PA 16802

Ph: (814) 865-2636
FAX: (814) 863 6132
Email: coupland@psu.edu

Education | Research Interests | Recent Publications | Video | Informational Web Site

Education:
	Ph.D. Leeds University, UK Food Science 1996 B.S. Leeds University, UK Food Science 1991
Research Interests:
	I coordinate the Ingredients as Materials research group in the department of food science. I am also a member if the Institute of Food Technologists and the American Chemical Society. My own research is involved with measurement of the physical properties of foods, especially lipids. Some examples are given below: Ultrasonic Sensors. Good sensors facilitate the automation of food production processes. Low power, high frequency sound can, in some cases, be the ideal sensor as it is non-invasive, non-destructive, and cheap. Ultrasonic methods are already available to measure several simple properties of foods including depth in a tank, flow rate in a pipe, and composition of simple binary solutions. Better data analysis could extend these applications to include measurement of emulsion particle size, polymer compressibility, crystallization of fats and sugars, and chemical kinetics - all without the need to disturb the sample. These sensors can readily be incorporated into an imaging system to detect contamination (e.g., glass, wood, or metal fragments) or structural inhomogineities in the food itself (e.g. air bubbles in cheese, sugar gradients. Current research in my lab has exploited ultrasonic sensors in reflectance mode to study the concentration and viscosity of simple solutions as well as phase transitons (melting and crystallization) in a number of systems. We are also concerned with non-invasive ultrasonic thermometry and the use on non-contact mode ultrasonics. Extending the Functionality of Food Polymers. Food macromolecules are frequently used to impart desired physical structure to foods (e.g., thickening, gel formation, stabilizing emulsions, film formation and microencapsulation). By studying the chemical and physical basis of the interactions responsible for functionality, it is possible to extend the range of use of existing ingredients and develop novel products. If a new role can be identified for a food ingredient, its value is often increased - particularly important for low-value or surplus food ingredients. Recent studies on the functionality of soy has elucidated a mechanism for the enhancement of protein solubility and viscosity by the addition of surfactants. Micellar Systems. Many amphiphilic molecules self-assemble in solution to form micelles. In aqueous solution, the micelle core provides a hydrophobic micro-environment, which can solubilize several lipid molecules. This process is fundamental to the understanding of such processes as the formation of emulsions, and their destabilization by dissolution or Ostwald ripening. On a more practical level, selective solubilization of oils into micelles offers a route to fractionation based on molecular size and polarity or, by the reverse process, to incorporate non-polar additives (e.g. flavors or antioxidants) into a pre-existing emulsion. I am currently working with Dr. Devin Peterson to develop ways to use micelles and food polymers as engineered flavor delivery vehicles. Work with Dr. Bob Roberts is underway on the roles of an added functional polymer in ice cream. Lipid Crystallization. Phase transitions in bulk and emulsified fat has important effects on the stability and sensory properties of foods. Lipid crystallinity is primarily affected by composition and temperature history and time but other factors (e.g., ultrasonic or shear fields) can be important. Recent research has focused on the effects of shear on lipid crystallization both in bulk and in the emulsified state and on the effect of lipid crystallization on the destabilization of oil-in-water emulsions (partial coalescence).

Recent Publications:
	Coupland, J.N., Z. Zhu, H. Wan, D.J. McClements, W.W. Nawar, P. Chinachotti 1996. Droplet composition affects the rate of oxidation of emulsified ethyl linoleate, J. American Oil Chem. Soc., 73:795. Coupland, J.N. and D.J. McClements 1996. Lipid oxidation in food emulsions, Trends in Food Science and Technology, 7:83. Weiss, J., J.N. Coupland and D.J. McClements 1996. Solubilization of hydrocarbon emulsion droplets suspended in nonionic surfactant micelle solutions. J. Phys. Chem., 100:1066. Coupland, J.N., J. Weiss, A. Lovy and D.J. McClements 1996. Solubilization kinetics of triacyl glycerol and hydrocarbon emulsion droplets in a micellar solution, J. Food Sci., 61:1114. McClements, D.J. and J.N. Coupland 1996. Theory of droplet size distribution measurements in emulsions using ultrasonic spectroscopy, Colloids and Surfaces A., 117:161. Vodovotz, Y., E. Vittadini, J.N. Coupland, D.J. McClements and P. Chinachotti 1996. Bridging the gap: The use of confocal microscopy in food research, Food Tech., 50:74. Weiss, J., J.N. Coupland, D. Brathwaite and McClements 1997. Molecular structure of hydrocarbons in emulsion droplets affects their solubilization in nonionic surfactant micelles. Colloids and Surfaces A. Coupland, J.N., D. Brathwaite, P. Fairley, and D.J. McClements 1997. Effect of ethanol on the solubilization of hydrocarbon emulsion droplets in nonionic surfactant micelles, J. Colloid Interface Sci., 190:71. Coupland, J.N. and D.J. McClements 1997. Droplet composition affects the rate of oxidation of emulsified ethyl linoleate - supporting evidence, J. American Oil Chem. Soc. 73:1207. Demetriades, K., J.N. Coupland, and D.J. McClements 1997. Physical properties of whey protein stabilized emulsions as related to pH and NaCl, J. Food Sci, 62:1. Demetriades, K., J.N. Coupland, and D.J. McClements 1997. The effect of temperature on the stability of whey protein stabilized emulsions. J. Food Sci, 62:462. Coupland J.N. and D.J. McClements 1997. A Compilation of Some Physical Properties of Liquid Edible Oils, J. American Oil Chem. Soc., 74:1559. Chanamai, R., J.N. Coupland, and D.J. McClements 1998. Effect of Temperature on the Ultrasonic Properties of Oil-in-Water Emulsions, Colloids and Surfaces A., 139:241. Ghaedian, R., J.N. Coupland, E.A. Decker and D.J. McClements 1998. Ultrasonic Determination of Fish Composition, J. Food Eng., 35:323. Coupland, J.N. and D.J. McClements 1999. Droplet Size Determination in Food Emulsions: Comparison of Ultrasonic and Light Scattering Methods. J. Food Eng. (accepted). T.K. Basaran, J.N. Coupland, and D.J. McClements (1999), Monitoring Molecular Diffusion of Sucrose in Xanthan Solutions using Ultrasonic Velocity Measurements, J. Food Sci., 64:125-128. Coupland, J.N. and D.J. McClements. 1999. Ultrasonic Characterization of Food Emulsions, in "Encyclopedic Handbook of Emulsion Technology", ed. S. Bjorno. (accepted). Coupland, J.N. and D.J. McClements 1999. Ultrasonics, in "NDT Methods for Foods", ed. S. Gunasekaran, Marcel Dekker (accepted). Coupland, J.N. 1999. Ultrasonic Characterization of Emulsions, Recent Res. Devel. Oil Chem., 2:115. J.N. Coupland, N.B. Shaw, F.J. Monahan, E.D. O'Riordan, and M. O’Sullivan (2000), Modeling the Effect of Glycerol on the Moisture Sorption Behavior of Whey Protein Edible Films, J. Food Eng., 43:25-30. C. Garbolino, G.R. Ziegler, and J.N. Coupland (2000), Ultrasonic Determination of the Effect of Shear on Lipid Crystallization, J. American Oil Chem. Soc., 77:157-162. S. Vanapalli and J.N. Coupland (2000). Characterization of Food Colloids by Phase Analysis Light Scattering, Food Hydrocolloids, 14:315-317 J.N. Coupland and D.J. McClements (2001), Ultrasonics. In "NDT Methods for Foods", Marcel Dekker, NY, ed. S. Gunasekaran J.N. Coupland and D.J. McClements (2001), Ultrasonic Characterization of Food Emulsions. In “Encyclopedic Handbook of Emulsion Technology”, ed. S. Bjorno, Marcel Dekker, pp. 233-242. J.N. Coupland, (2001), Ultrasonic Characterization of Lipid Crystallization, In: “Crystallization and solidification Properties of Lipids”, eds. N. Widlak, R. Hartel, S. Narine, pp. 132-146, AOCS Press, Champaign, Illinois. R. Saggin and J.N. Coupland (2001). Oil Viscosity Measurement by Ultrasonic Reflectance, JAOCS, 78:509-511 R. Saggin and J.N. Coupland (2001). Concentration Determination by Acoustic Reflectance, Journal of Food Science, 68:681-685.

For more information contact:

Juanita Wolfe, Graduate and Undergraduate Program Contact
110 Borland Laboratory
University Park, PA 16802
Ph: (814) 863 8667
Email:jmw5@psu.edu

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Last Update was October 4, 2002