With holiday barbeques coming up, revelers may hear warnings about not charring their meats to avoid creating carcinogens. Perhaps cooks can take a lesson from Taiwanese chefs. New research shows traditional Chinese recipes and cooking methods put a damper on these unhealthy by-products.
All sorts of chemical reactions crop up in cooking. Cholesterol in animal products can be converted into carcinogenic cholesterol oxidation products (COPs). And those charred crusty bits on your barbequed ribs? Part burned fat, which could be unhealthy, and part Maillard reaction products (MRPs), which arise from reactions between proteins and sugars--the common source of browning on toast and sliced apples. Some research suggests these MRPs have anti-oxidant properties and may be able to counteract the effect of COPs.
Food chemist Bing-Huei Chen at Fu Jen University in Taiwan wanted to investigate whether traditional cooking methods have an effect on COP and MRP levels. In Taiwan, cooks simmer ground pork and hard-boiled eggs in a marinade of soy sauce and sugar for at least an hour, and out on the streets of Taiwan, merchants can have their treats simmering for many hours.
To determine what secrets the preparation harbors, Chen and colleagues determined the amount of COPs in ground pork cooked for 24 hours in marinades with varying amounts of soy sauce and/or sugar. The concentration of COPs in the pork totaled 2226 nanograms per gram of pork when cooked in water alone. Ten percent soy sauce cut that by 63%, and 10% sugar cut COPs 71%. The traditional recipe--10% soy and 1% sugar--brought the COPs in the pork down 60%.
The researchers then measured the effect of soy sauce or sugar on the Maillard browning reaction. Both ingredients bumped up reaction products in the food, suggesting that the marinades generate MRPs that inhibit COP formation, the team reports in an upcoming paper of the Journal of Agricultural Food Chemistry.
Food chemist and toxicologist Steven Schwartz of Ohio State University in Columbus says this could be the first example that MRPs cut the amounts of COPs in food. But he doubts that the results will significantly change the way people prepare food in the United States, because COPs are only harmful in massive quantities. As far as substituting in long marinades for a holiday barbeque? "I wouldn't," he says, suggesting instead to avoid the charred bits of fat that are common in American barbeques.