Smoke can infuse foods with delightful, elegant flavors, but it can also add some unwanted carcinogens. To get rid of these intruders, researchers are taking a page from the auto industry.
I remember when I first came across a type of tea called Lapsang souchong -- a unique variety of black tea, smoke-dried over pinewood fire. It was a spectacular aroma and it sent me on a smokey frenzy, chasing all the smoked foods I could find. Likewise, many people enjoy smokey flavors -- whether it's cheese, meat, or even whiskey -- but not too many are aware of the downsides of the smoking process.
"The smoking process can cause carcinogens to form in foods. Not all smoked foods are dangerous, but we do know most can contain low levels of these substances, so we should try to remove them. If we could produce a smoke with fewer carcinogens, but that still has the same great taste, that would be ideal," says Jane K. Parker, Ph.D., leader of the study.
With this in mind, Parker and her colleagues developed filters made from zeolites -- microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts -- remove as many carcinogenic polycyclic aromatic hydrocarbons (PAHs) from smoke as possible. This is a technique commonly used in the auto industry to reduce emissions.
"Zeolite filters, which are put in a tailpipe, have been used in the car industry to reduce environmental pollutants, but they haven't been applied to food yet. We want to change that."
The most efficient filter they designed eliminated 93% of carcinogens, but the problem of taste remained -- did they also remove 93% of the smokey taste? In order to test this, researchers had a panel of expert tasters try out smoked tomato flakes, coconut oil and water using either filtered or unfiltered smoke. They found that the filtered smoked foods had a much more rounded and balanced flavor, tasting even better than the unfiltered ones.
This was a bit surprising, so Parker took to mass spectrometry to analyze the compounds in the two types of smoke, trying to figure out what caused the differences.
"The profiles showed that it was largely the higher molecular weight components that were being removed by the filter," Parker says. "These chemicals may be the ones giving the foods a harsher flavor and aroma profile."
So not only does the filter make things much healthier, it also makes them taste a bit better. So far, the study hasn't been peer-reviewed but was presented at the 255th National Meeting & Exposition of the American Chemical Society.
