The authors of this new paper have really cooked up something interesting! “Microbial Safety of Wood in Contact with Food: A Review” by Florence Aviat, et al and published in Comprehensive Reviews in Food Science and Food Safety is an 86-reference review on materials found in kitchens. Elisabeth Bik did list this in her March 7 blog of new papers, but this one is too good to not have it’s own post. Russell Neches wrote a great post about this topic in June of 2014 here on microbe.net as well.
We are so quick to criticize food safety practices, especially with large businesses. Despite scientific proof, people still think that wood is an unhygienic alternative to plastics, glass, and metals due to its porous nature that may be hard to sanitize. This review paper is very thorough, and even comments on laws in numerous countries about what/when using wood is ok. This review provides enough evidence to persuade even the strongest of skeptics that wood is a viable material in our food storage and preparation techniques.
Here are some highlights from the paper:
- Wood is an extremely broad topic, so the authors characterized the wood by: tree species, intended use, heterogeneity, hygroscopicity, anisotropy, elasticity, impregnability and acidity.
- “To date, wood in contact with food has not been found responsible for any food-borne outbreak”
- A paper by Abdul-Mutalib and others (2015) reported that “the microbial abundance on cutting boards from different grades of food premises was very similar. In addition, these authors did not reveal a correlation between the cutting board material and the bacterial abundance identified on it.”
- It is really hard to recover microbes from wooden surfaces, and the best known method is to obliterate the sample, which may not be possible in some circumstances.
- There are an insane amount of antimicrobial properties of wood such as physical (e.g. low oxygen environments), and chemical (e.g. enzymes, tannins), and biological (other microbes).
- The review talks about numerous papers that compare different types of wooden cutting boards to different types of plastic cutting boards, all finding that they are equally hygienic. Some of the studies even focus on particular culprits of food borne illness, such as Salmonella, E. coli, and Listeria. It was found, however, that microorganisms could penetrate wooden boards more easily than plastic ones — the porous nature, contact time with food, humidity, and storage temperatures also influenced microbial adhesion and survivability. However, the properties of the wood don’t make this a threat to food safety.