Zeolite filters out carcinogens from smoke flavoring

Infusing foods with smoke can create delicious flavors, but the process also can introduce small amounts of carcinogenic compounds into the food. At the meeting, the University of Reading’s Jane K. Parker reported that filters made from a microporous aluminosilicate material called a zeolite reduced the levels of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in smoke by as much as 93%. Parker’s team used a naturally occurring type of zeolite called clinoptilolite to filter smoke from oak wood before using it to prepare food. They found that the filter worked best when they activated the zeolite with heat and ground it into a fine powder to maximize the surface area in contact with smoke. The zeolite reduced the levels of benzo[a]pyrene, a type of PAH that the International Agency for Research on Cancer classifies as a known human carcinogen, by 93%. Concentrations of several other PAHs also dropped, many by more than 70%. A panel of 12 expert tasters evaluated chicken brined in smoked water and cream cheese mixed with smoked tomato flakes, prepared with either filtered or unfiltered smoke. The tasters described the filtered smoke flavor as more balanced, with less bonfire- and diesel-like flavors than foods prepared with unfiltered smoke.