Liquid Smoke

Smoking out microbes

Liquid smoke, a dark fluid made from condensed wood smoke, is a well-used flavourant and ingredient. Recent research now shows it has useful added functionality as an antimicrobial.

A recent review penned by Philip G Crandall, a University of Arkansas food science professor, and co-workers have found that liquid smoke can kill harmful food-borne pathogens, such as Listeria monocytogenes, Salmonella, Escherichia coli, and Staphylococcus (see Meat Sci. 2014, DOI: 10.1016/j.meatsci.2014.02.003).

It’s not certain what precise chemical mechanism of action is responsible for liquid smoke’s antimicrobial activity, Crandall points out. Both phenolic compounds and carbonyl compounds are thought to contribute to the ingredient’s pathogen-fighting powers.

The growing consumer demand for all-natural foods may prompt some food companies to use liquid smoke for food safety, Crandall notes. It is already being used as a preservative for meat, fish, and cheese, “because it imparts a pleasant flavour and also has inhibitory effects on food-borne pathogens,” he says.

Liquid smoke also has several advantages over traditional smoking techniques, Crandall adds. It’s easy to use, and it imparts flavours to food faster than traditional smoking.

Also, liquid smoke doesn’t contain the hazardous polycyclic aromatic hydrocarbons that are a by-product of wood burning. That’s because these aren’t water soluble, so they get filtered out in the process of making liquid smoke.

Liquid smoke adds some nice notes to different food, says Crandall. “As long as you don’t go nuts with it, it brings out a lot of the savoury flavours,” he says, noting that he likes to put a few drops in scrambled eggs.

Liquid smoke, too, is often the secret ingredient in soups, ribs, and, surprisingly, chocolate chip cookies. [Wonder why there are not obvious consumer versions of liquid smoke available? … a few moments later, a quick Google search uncovers just such a newish business in South Africa! See, whose products are pictured above. Ed]