The Larch!

When I was a teenager I often watched a show on TV (Monty Python's Flying Circus; I was adventurous and young at the time.) that had a funny running dialogue concerning an unusual tree. It is an evergreen (conifer) that loses its needles in the fall like the deciduous trees (maples, oaks, etc.) do. It is called the larch tree.

This particular tree is quite common in the northwestern parts of the United States and an extract from it has been shown to suppress the growth of Salmonella in chicken and E. coli in meat. Discovered at the University of Montana in Missoula by carbohydrate chemist Geoffrey Richards, the wood extract has been patented by the University of Montana and licensed to Larex, Inc., in St. Paul, MN.

This extract does not change the color or the flavor of the food. It contains the polysaccharide arabinogalactan as well as polyphenols. Both arabinogalactan and the polyphenols have been regarded as "safe" by the FDA.

Arabinogalactan has been used as an emulsifier and stabilizer. Polyphenols, such as flavonoids, occur naturally in many plant foods. Of the two major components, the polyphenols suppress bacterial growth.

When chicken is rinsed in a 5% solution of this larch tree extract the Salmonellaplaced on the surface of the chicken grows very slowly. A large number of Salmonella are needed to cause infection in humans. By slowing the bacterial growth this extract can prevent many Salmonella infections.

In similar experiments with fresh beef this larch extract suppressed the growth of Escherichia coli. The larch extract blocks bacterial growth 30-70%, depending on conditions. The extract can be applied by dipping, rinsing, spraying or brushing, and can be used to protect meat, poultry, eggs, vegetables and fruit.

The larch extract is obtained from the bottom 15 feet of the tree trunk, which is usually discarded by the lumber industry.

Researchers at Larex Inc. hope to develop a dipping solution for use in meat and poultry processing plants. They also may develop a product for cleaning sinks and countertops. The exact mechanism of action of the extract remains unknown. However, chemical toxicologist Sandy Bigelow, vice president of research and development at Larex, suggests that because arabinogalactan is a natural emulsifier and stabilizer it likely makes the cell surface of food bacteria more sensitive to the antibacterial action of the polyphenols.

A tree involved in a funny TV skit yesterday may become the antimicrobial treatment of tomorrow. Truth is oftentimes stranger than fiction.

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