When meat is cooked at high temperatures, heterocyclic amines (HCAs) are produced. Many of these are suspected human carcinogens. While HCAs haven't been proven to cause cancer in humans, they cause mutations in both bacteria and mice, and that's troubling, so less is better than more when it comes to them.
Higher cooking temperatures produce more HCAs. Barbecuing produces the most. Pan frying and broiling also produce high amounts. Boiling, stir-frying, poaching and stewing are the cooking methods that produce the least.
All three marinades contained at least two spices from the mint family.
The new study is good news if you're a grilling enthusiast. The research by Dr. J. S. Smith and his team at The Food Science Institute, Kansas State University suggests that marinating meat before cooking it can greatly reduce the presence of HCAs, especially if spices are used.
In the study, meat marinated in three commercially-available marinades lowered HCA formation by 55-88%. The Caribbean marinade (thyme, red pepper, black pepper, allspice, rosemary, chives) worked best, followed by the herb (oregano, basil, garlic, onion, jalapeno pepper, parsley, red pepper) and Southwest (paprika, red pepper, oregano, thyme, black pepper, garlic, onion) blends. The spices in the marinades appeared to account, on average, for about 40% of this HCA decrease. Curiously, marinating the meat in just water, oil and vinegar before cooking caused a slight increase in the amount of HCAs.
All three marinades that were used contain at least two spices from the mint family. These spices contain various antioxidants that are thought to play a role in reducing HCA formation.
The researchers purchased dry packets of commercial marinade mixes at a local grocery store. These were mixed with water, oil and vinegar to produce the marinating liquid. They were also able to obtain dry marinade mix without any spice content from the manufacturer. This allowed them to determine the effect caused by the spices.
The study used 3.3-ounce eye of round steaks that were marinated for one hour. The steaks were then cooked on a Teflon-coated electric grill with a temperature controller for five minutes per side, at 400 degrees Fahrenheit. The amount of HCAs in the unmarinated, marinated and marinated but spice-free cooked steaks was then determined. The results were published in the August 2008 issue of the Journal of Food Science.
Dr. Smith thinks that the HCA reduction would have been even more dramatic if the steaks had been cooked on an outdoor grill, which cooks at higher temperature.
Marinating changes the flavor and texture of meat. Many people feel that it improves both. It seems like cheating to be able to make meat safer and better tasting at the same time. But that's what the study suggests marinating meat can do.