To Block the Carcinogens, Put Rosemary on the Line
21-May-2008 12:00 AM EDT
Newswise — Rosemary, a member of the mint family and a popular seasoning on its own, also has benefits as a cancer prevention agent. Apply it to hamburgers and it can break up the potentially cancer-causing compounds that can form when the meat is cooked.
J. Scott Smith found out about rosemary's strength against the compounds while researching ways to reduce them as part of a long-term Food Safety Consortium project at Kansas State University. Smith, a KSU food science professor, has been looking into the carcinogenic compounds known as HCAs (heterocyclic amines).
"Put a little bit on the surface," Smith advised grillers. "Rosemary extracts shouldn't have much of an aroma to them. Most people don't want a rosemary-flavored burger. So if you get the extract you don't really know it's there."
Smith's findings began with research into commercial rosemary extracts' effect on stopping HCAs from forming in cooked beef patties. His research group found that the HCAs were reduced in levels ranging from 30 to 100 percent.
The presence of HCAs is a potential problem in cooked beef. The likelihood of their presence is influenced by cooking time and temperature. Previous studies showed that meat products cooked below 352 degrees Fahrenheit for less than four minutes had low or undetectable levels of HCAs. The HCAs would increase as temperature and cooking time increased.
Although lower temperatures and shorter cooking times can reduce the risk of HCA formation, those alternatives have their own problems. Lower temperatures can affect the taste adversely, Smith explained, noting that commercial steak houses cook at temperatures above 400 degrees F.
"Some use real high temperatures quick on the surface, then they pull it out and put it in an oven to finish it," he said.
The better way may be to use rosemary extracts so temperatures can be still be kept high. Rosemary's antioxidant content makes this method possible thanks to the presence of phenolic compounds. Those compounds " rosmarinic acid, carnosol and carnosic acid " block the HCAs before they can form during heating.
The results of the rosemary research tie in with previous findings from Smith's group. Those studies showed that marinating steaks with certain herbs and spices also reduces HCAs. Rosemary is among those herbs and spices with basil, mint, sage, savory, marjoram, oregano and thyme, all rich in antioxidants.
Marinating with any of these store shelf spices adds a healthy boost to grilling steaks, just as rubbing rosemary extracts onto burger patties is beneficial. Smith said rosemary extracts are for sale on the Internet.
"The industry is moving toward an extract that you can rub onto the surface, or a rub that you can mix into the power to get better flavor to the hamburger," he said.
That may not be all. Antioxidants can have other benefits besides curtailing HCAs, Smith said. "There is some indication that they protect the pancreas. If you can get that from burgers, then that's great."