Fruit and Vegetable Products Specialist
Department of Food Science and Technology

114 Food Sci. & Tech.
dmbarrett@ucdavis.edu
(530) 752-4800 office
(530) 754-7677 fax
       

Education

Ph.D. in Food Biochemistry, Cornell University, 1989
Minor subjects: Plant Physiology and Agricultural Economics
M.S. in Food Chemistry, University of Wisconsin, Madison, 1980
B.S. in Food Science, University of California, Davis, 1978

Keywords

PROFESSIONAL EXPERIENCE

Extension Specialist, Fruit and Vegetable Products
45% Research   55% Extension
Department of Food Science and Technology, University of California, Davis, September 1992 to present

Research addresses the effects of handling and processing on color, flavor and texture of fruits and vegetables, with particular emphasis on enzyme-catalyzed reactions which result in qualitative losses. Handling and processing technologies of interest include cold and controlled atmosphere storage, modified atmosphere packaging, canning, freezing and aseptic processing. Extension activities include developing strong linkages with California fruit and vegetable processors, associations such as the California League of Food Processors and the National Food Processors Association, commodity and advisory boards, appropriate state and federal government personnel and both farm and home advisors. Coordination of the Better Process Control Schools; Freezing Technology Course; Aseptic Processing & Packaging Course; and Juice Processing, Quality and Safety Workshop.

Assistant Professor, Fruit and Vegetable Handling and Processing
50% Research   50% Extension
Department of Food Science and Technology, Oregon State University, Corvallis, Oregon, 1989 to 1992

Tuber Crops Postharvest Processing Specialist
Dept. of Agriculture, Republic of Indonesia,  Funded by U.S. Agency for International Development, 1983 to 1985

Curriculum Development Consultant
Dept. of Community Nutrition, Bogor Agricultural University, Funded by U.S. Agency for International Development, 1982 to 1983

Food Chemistry Consultant
Food Technology Development Center, Bogor Agricultural University, Funded by World Bank, 1981 to 1982

Research Interests

RESEARCH OBJECTIVES - LAY TERMS
The objectives of my research are to work with the California fruit and vegetable processing industry to ensure that they provide consumers with high quality fruit and vegetable products. Preservation of the color, flavor, texture and nutritional value of processed fruit and vegetable products is a challenge. My laboratory studies the effects of processes such as freezing, canning, aseptic and minimal processing on the quality of horticultural products.

RESEARCH OBJECTIVES - FOR PEERS
My research focuses on the effects of fruit and vegetable handling and processing on enzyme-catalyzed reactions which result in qualitative loss in color, flavor and/or texture. Enzymes of interest include peroxidase, lipoxygenase, hydroperoxide lyase, polyphenol oxidase, polygalacturonase, pectin methyl esterase and cystine lyase. Handling and processing technologies of interest include cold and controlled atmosphere storage, modified atmosphere packaging, minimal processing or fresh-cut, canning, freezing and aseptic processing.

RECENT SIGNIFICANT FINDINGS/ACCOMPLISHMENTS

• Optimization of diced tomato texture. Effects of calcium addition on turgor pressure, cell wall and middle lamella integrity and composition. (Ph.D. student Irene Luna-Guzman).
• Modeling of quality parameters in tomato, carrot and potato homogenates. Kinetics of thermal inactivation of enzymes (polyphenol oxidase, pectin methyl esterase, polygalacturonase, peroxidase, lipoxygenase) and quality factors. (Research Associate Dr. Gordon Anthon).
• Maintenance of textural integrity of blanched, frozen and micowaved shredded vegetables. Effects of low temperature blanching and addition of calcium salts. (Research Associates Dr. Ni Li and Danny Lin, MS)
• Optimization of pre-drying treatments (blanching, sulfur/sulfite dips, salt) prior to production of sun-dried tomato products. (MS student Lupe Latapi)
• Prediction of peelability and product yield in California-grown tomato varieties. Identification of physical parameters which may be modeled to predict direction to either paste or whole peel/diced tomato processing.
• Determination of the antioxidant properties of clingstone peach carotenoids and polyphenolics. Effects of cultivar, maturity and various processing methods. (with Dr. Alyson Mitchell)