The ability of green tea flavonoids to control Maillard browning was investigated. Epicatechin (EC) and epigallocatechin gallate (EGCG) were added at levels of 0.l and 1.0 mmol/l to a glucose/glycine model system as well as into milk that was then thermally processed in a Microthermics processing system. Samples were assessed with (1) front-face fluorescence spectroscopy for Maillard browning, (2) Hunter L*, a*, and b*; and (3) sensory analysis. In the model gluocose/glycine system, EC and EGCG reduced Maillard fluorescence at the 0.1 mmol/l level, while fluorescence was negligible with added flavonoids at 1.0 mmol/l. When these flavonoids were added to milk, they reduced the production of Maillard associated fluorescence with UHT processing. EC and EGCG also reduced the ΔE (Total color difference) during thermal processing. Throughout shelf-life testing, these compounds reduced Maillard associated fluorescence in milk. Milk samples processed with these extracts were monitored by sensory analysis during extended storage. The sensory evaluation found the green tea milk samples to be of similar liking to the control milk. These flavonoids may be of use to the food industry to control Maillard browning.
Bibliographical noteFunding Information:
This research was funded by Dairy Management Inc. and in part by a US Department of Homeland Security grant to the Center for Food Protection and Defense, University of Minnesota. The authors thank Ray Miller, Peng Zhou, Kelsey Ryan, and Armen Czepyha for technical assistance, Dr. Lloyd Metzger for providing the fluorescence equipment, and Dr. Devin Peterson and Julie Peterson (Penn State University) for conducting the sensory work.
Copyright 2008 Elsevier B.V., All rights reserved.
- Epigallocatechin gallate
- Maillard browning