Professor of Food Engineering
Director, Packaging and Biopolymer Film Laboratory
Department of Food Science and Technology
Department of Biological and Agricultural Engineering

237 Cruess Hall
jmkrochta@ucdavis.edu
(530) 752-2164 office

Education

Ph.D. in Chemical Engineering, University of California, Berkeley, 1971        

Research Interests

Professor Krochta's research involves study of polymer film formation, transport characteristics, modeling, and application to food packaging and biological systems.

Edible Films: The focus of this research includes the underlying chemistry and mechanisms affecting film formation and morphology, and the resulting film permeability and mechanical and sensory characteristics of the films. New approaches to forming films from proteins have been developed. Results show that milk protein films are excellent oxygen barriers at RH < ~50%. Utilizing the emulsifying ability of milk proteins has produced protein-lipid composite films with >90% reduction in moisture permeability. Lipid type, amount, and particle size all have important impact on film morphology and properties. Work continues to further improve the moisture barrier of composite films, extend the oxygen barrier over a larger RH range, and quantify the aroma and lipid barrier properties of films. Lack of understanding of edible films prevents selection of appropriate materials and design of systems with the desired characteristics.

Edible Coatings: Other research is underway to take advantage of moisture, oxygen, aroma, and lipid barrier properties of edible films formed as coatings on food products. Research in this area involves investigation of coating formulation surface tension and viscosity effects on wetting and spreading of coating formulations on foods with hydrophobic and/or porous surfaces, coating formulation and drying condition influences on adhesion and integrity of food surfaces, and assessment of oxygen, moisture, aroma, and lipid barrier properties of optimized film coatings on different classes of food products. This research involves mathematical modeling of film-coated foods, methodology for forming films as coatings on foods, and shelf-life studies of coated foods to confirm modeling approaches.

Controlled Release: Additional research extends to the areas of controlled release of food ingredients, pharmaceuticals, and pheromones from edible and biodegradable materials. This includes synthesis and characterization of useful biodegradable polymers from lactose.