Nieky Van Veggel: The effect of carvacrol, thymol and eugenol vapour on the growth of Escherichia coli

Writtle College logoThe aim of this study was to determine whether vapours from carvacrol, eugenol and thymol can inhibit the growth of Escherichia coli. Escherichia coli, which is found in a wide variety of foods is the cause of many outbreaks of food-borne illnesses (Burt and Reinders, 2003). Meat products can become contaminated during slaughter and a high incidence of E. coli has recently been reported in ewe’s milk (Caro et al., 2011). A recent outbreak from bean sprouts in Germany affected 3,950 people and lead to 53 deaths and an estimated loss of $2.84 bn in human damage (Marler, 2011).

Carvacrol, thymol and eugenol have promising possibilities as food preservatives (Gutierrez-Larrainzar et al., 2012). These compounds are “generally recognised as safe” (GRAS) flavourings in the U.S. and E.U. (European Parliament, 2008; U.S. Food and Drug Administration, 2012). However, some of the limitations of these phytochemicals are caused by their herbal aroma and their capability to affect physical properties of meat. Recent research (Burt et al., 2007; Tyagi et al., 2012) has shown that carvacrol vapours show antibacterial activity against a selection of food pathogens. However, no research has been done on the effects of eugenol or thymol in vapours.

In this study the optimal inhibition of E. coli was found by using 10 mg carvacrol, however, all three phytochemicals have the ability to inhibit E. coli growth in vapour phase. Future research into optimal delivery methods is currently being performed.

References

Burt, S.A. and Reinders, R.D. (2003). Letters in Applied Microbiology, 36, 162-167,

Burt, S. A., Fledderman, M. J., Haagsman, H. P., van Knapen, F. and Veldhuizen, E. J. A. (2007). International Journal of Food Microbiology, 119, 346-350.

Caro, I. and Garcia-Armesto, M.R. (2011). International Journal of Food Microbiology, 116, 410-413.

European Parliament (2008) Regulation (EC) No 1334/2008. Official Journal of the European Union, L354/34.

Gutierrez-Larrainzar, M., Rua, J., Caro, I., de Castro, C., de Arriaga, D., Garcia-Armesto, M. R. and del Valle, P. (2012). Food Control, 26, 555-563.

Marler, B. (2012). Food Poison Journal.

Tyagi, A.K., Malik, A., Gottardi, D. and Guerzoni, M.E. (2012. Trends in Food Science and Technology, 26, 99-113.

U.S. Food and Drug Administration (2012) Code of Federal Regulations Title 21 part 172.

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