Increased consumption of flavonoids, which occur naturally in plant foods, has been associated with reduced risk for cardiovascular disease. However, flavonoids are often removed in processing because they are bitter.
The new Penn State research shows that the presence of flavonoids at heart healthy levels does not automatically increase bitterness but can actually promote good flavor development and palatability in some food products.
Dr. Devin Peterson, assistant professor of food science and director of the study, says, "Our research has shown that in food and beverage products that are heated for safety or preservation, flavonoids can limit the generation of off-flavors, such as the scalded or cooked taste of ultrapasteurized milk. We've also found that it may be possible to enhance some good flavor pathways while limiting others, including less desirable smells, by the addition of flavonoids."
Peterson presented his results today (Sept. 9) at the 226th American Chemical Society national meeting in New York, N. Y. His paper is titled, "Influence of Flavonoids on the Thermal Generation of Aroma Compounds."
Peterson and his research group added three different levels of epicatechin, a flavonoid typically found in fresh fruits, vegetables, tea and chocolate, to whole milk and then ultrapasteurized it. Tests with a trained panel of tasters found that all samples containing the flavonoid were significantly lower in cooked flavor and one was indistinguishable from regular pasteurized milk, which has no cooked flavor at all.
Experiments with a granola bar mix to which epicatechin had been added showed that the flavonoid inhibited the formation of some flavor constituents produced in browning, including a powerful flavor/off flavor regulator. Nevertheless, taste testers did not detect an increased level of bitterness in the epicatechin-enriched granola bar versus the control.
In other experiments, the power of epicatechin to affect flavor was demonstrated when the flavonoid was added to unroasted cocoa and then heat processed. The flavonoid reduced by half the production of the two major flavor constituents.
"Adding flavonoids to food products at efficacious levels does not have to result in increased bitterness and consumer rejection. By understanding how health-promoting flavonoids alter flavor generation, we can learn how to produce healthier foods that taste good too," Peterson says.
Peterson's research was supported by start-up funds from Penn State's College of Agricultural Sciences. Penn State has filed a provisional patent application on Peterson's process for flavor improvement.