Dr. Maurice R. Marshall
Dr. Marshall’s research group focus is on the chemical and biochemical reactions that influence the quality and stability of foods with emphasis primarily on seafood, and fruits and vegetables. Students at the undergraduate, masters, doctoral and postdoctoral levels are working in five specific areas, and work collaboratively with food science faculty in engineering, chemistry and extension, and faculty in microbiology and cell science and entomology.
In seafood, the group focus is on analysis and detection of biogenic amines as quality indicators of spoilage. They are also interested in understanding the role specific amino acid precursors play in the formation of biogenic amines. They have two projects that focus on the chemical and biochemical changes in seafood. One specific focus is on the quality and stability of various seafood after treating with pressures approaching 600 MPa for various times. Chemical analysis, sensory, texture, color and microbiology of the processed products are evaluated. The second project is specifically looking at biotoxin inactivation and omega-3 fatty acid stability in red versus white muscle after high hydrostatic pressure treatment.
In fruits and vegetables, Dr. Marshall’s research group is working on the chemical and biochemical stability of tropical fruit juices treated with a continuous high pressure carbon dioxide process developed in the Food Science and Human Nutrition Department. Chemical analysis, flavor, sensory, color, and microbiology of the finished products are evaluated. A second project in this area focuses on the biochemical and molecular properties of enzymes, specifically polyphenol oxidases (browning enzymes), and unique inhibitors from insect and organic acids that prevent discoloration in fruits and vegetables. Presently, peptides/proteins are being isolated from insects and characterized as to their inhibition on polyphenol oxidase. Oxalic acid is also being studied as to its mechanism of inhibition on these enzymes.