Arkansas Agricultural Experiment Station, University of Arkansas Division of Agriculture
Dale Bumpers College of Agricultural, Food and Life Sciences

A newsletter for faculty, staff and students

September-October 2005 • Vol. 31, No. 5

Green tea, grape seed extracts restore chicken’s qualities

Anyone who ever left cooked chicken in the refrigerator a little too long has noticed what happens. The color doesn’t look quite right. A thorough cooking will make sure it’s safe, but it has a flavor that doesn’t seem on target.

Too bad about that. Some green tea and grape seed extracts could have helped.

Chicken meat going through the process of lipid oxidation can lead to the deterioration of certain organic compounds. Chicken meat lipids can be oxidized during processing, and cooking can cause rancidity. But irradiation, which can keep the chicken safe from pathogens, especially accelerates lipid oxidation.

Laboratory experiments show that infusing extracts of grape seed and green tea into the chicken before cooking or irradiation can slow down the lipid oxidation process, making the product more palatable.

“It’s very effective whether you irradiate it or not,” said Navam Hettiarachchy, a food science professor at the University of Arkansas Division of Agriculture, where she is looking into the project for the Food Safety Consortium. “It’s effective when you infuse the grape seed extract into the chicken breast before irradiation. You can minimize the lipid oxidation and extend the shelf life.”

Processors can also infuse the synthetic antioxidant TBHQ into chicken as a way of minimizing oxidation. Although it is a pure compound and is considered the best of its kind, there is still some hesitancy among processors to use it mainly because it is synthetic.

“Processors prefer not to use TBHQ because it is a synthetic antioxidant and they have concerns about the toxicological effects,” Hettiarachchy said. “That’s why plant extracts are preferred. On the other hand, plant extracts have a lot of polyphenolics (antioxidant compounds).”

 Cooking the chicken has other side effects. It increases the volatiles in irradiated and non-irradiated poultry, particularly volatiles that give an off-flavor. The lipid oxidation that results from cooking is less than the level that occurs from irradiation, but in either case grape seed extract can minimize the problem.

Other recent studies at Arkansas show that grape seed extract increased the lightness and decreased the redness and hardness of the skinless, boneless chicken breast meat. The green tea infusions were found to prevent and minimize major sensory changes during irradiation. Panels of sensory testers have found no significant difference in taste between irradiated and non-irradiated chicken breast infused with grape seed and green tea extract.

While researchers are looking for ways to make the sensory aspects of irradiated poultry acceptable to consumers, they are well aware that public acceptance of irradiated products themselves still remains a challenge for marketers. The use of extracts from grape seed and green tea can at least keep poultry in a sensory state already familiar to consumers.

 “Infusing the extract into the chicken meat would be helpful in minimizing lipid oxidation and you don’t have to be concerned about discoloration of chicken meat,” Hettiarachchy said. “The concentrations we are using do not impart any color or undesirable flavor.”

The research team wants to determine if the extracts can further enhance minimizing lipid oxidation and also enhance consumer acceptance. “We are shooting to see if we can come very close to the quality of synthetic antioxidant TBHQ,” Hettiarachchy said.