Time for some science :) I am going to review thymol, what it is, what it is found in, its antimicrobial properties, and its potential use in the poultry industry.
What is it?
Thymol (also known as 2-isopropyl-5-methylphenol), pronounced:
\ˈthī-ˌmȯl, -ˌmōl\
This is a monoterpene phenol found in thyme essential oil (EO). Monoterpenes are a fancy name for describing a specific class of compounds based on structure (just like proteins describe a specific class of compounds). Below is the structure of thymol.
Thymol constitutes 37-55% of thyme essential oil. Thymol can also be found in oregano oil (0-5%) and mountain savory oil (14-24%).
Thyme is a common herb used in cooking and can be found in several seasoning blends. It is also pretty easy to grow in the garden. Thyme has a long history and has been used by the Egyptians, Greeks, Romans, and during the Middle Ages.
What is it found in?
Thymol is found in several commercial products including:
Vicks Vapor Rub - It is listed as an inactive ingredient, along with nutmeg oil
Listerine Cool Mint Mouthwash - Also included in this mouthwash are several compounds that are found in essential oils (eucalyptol: found in eucalyptus EO, menthol: found in peppermint EO, and methyl salicylate: found in wintergreen EO)
EcoSmart Organic Home Pest Control - Contains thyme oil, and it also has clove, rosemary, and peppermint oils
Thymol is also commonly found in over-the-counter products for removing nail fungus.
Thymol: Antimicrobial Properties
Numerous scientific studies have shown that thymol can inhibit bacterial growth. As you can see in the graph below, when the
concentration of thymol increased from 0 to 1000 parts per million (ppm), there
was a corresponding decrease in bacterial growth. This inhibition of growth was
seen in several pathogenic species of bacteria including: Escherichia coli, Salmonella Typhimurium, and Clostridium difficile. Most of the bacteria tested were unable to grow at concentrations greater than 300 ppm of thymol. Other scientific studies showing antimicrobial effects of thymol include: Mith et al 2013; Wells et al 2014; Grilli et al 2012; Shaw et al 2012; and Olasupo et al 2003. In addition to bacteria, thymol can also inhibit fungus and molds (
Klaric et al 2007).
Thymol in the Poultry Industry
Thymol is one of several essential oil-based compounds, along with trans-cinnamaldehyde, eugenol, and carvacrol, being investigated by the poultry industry as a way to prevent bacterial contamination of poultry products (
Venkitanarayanan, et al 2013). Salmonella and Camplyobacter are two major bacterial contaminants of poultry products (remember, your mom probably told you not to eat raw cookie dough), and the poultry industry is looking for a way to limit bacterial growth and contamination of chickens and thus reduce human disease.
Closing
This post has been a brief overview of thymol, its use in commercial products, its antimicrobial activity, and its use in the poultry industry. Many other potential applications of thymol exist that I have not discussed (did you really want to read about cow manure?) I hope you have a better understanding of thymol and the potential applications of essential oils.
Thanks for stopping by!