Listeriosis is one of the worst foodborne diseases – the death rates are higher than most, even those caused by Salmonella. Listeria monocytogenes is a nasty bacterium causing everything from muscle aches, to fever and gastrointestinal problems at best, let alone death. Recalls of RTE foods such as meats and cheese are relatively common because Listeria is so prevalent. One of the problem RTE foods is guacamole which was initially thought to be a problem until some of the results indicated that it might not be as susceptible as first thought because of the avocado pulp (Strydom et al., 2013).

A recent study by researchers at Tecnologico de Monterrey in Mexico discovered that extracts and isolated compounds from avocados, and especially their seeds, might be used as a natural anti-microbial and additive in ready-to-eat foods in order to control listeria growth. Avocado is rightly regarded as one of the most nutritious foods available even though more people suffer cut injuries with knives trying to open them !

The avocado flesh and especially the seeds contains compounds known as acetogenins which have been shown to act against Listeria. The method of inhibition has still to be worked out but the discovery shows promise against what is a very difficult bacteria to control. As with most antimicrobials, the acetogenins are thought to disrupt the cell wall of the bacteria. Avocado seeds are generally a large waste material and any value to extract from them would be highly beneficial. The research group cautions that safety aspects to eating acetogenins need to be considered. 

Acetogenins are naturally occurring lipids from avocado fruit, which show  antimicrobial, antiplatelet, antioxidant and antithrombotic activity (Hernández-Brenes et al., 2012; Rodríguez-Sánchez et al., 2013a, 2013b, 2015). Two new structures were reported (Rodríguez-Sánchez et al., 2013a) and, recently, two putative acetogenins were identified in a study with 22 avocado cultivars (Rodríguez-López et al., 2015) which extends the acetogenin pool to eight molecules.

References

Hernández-Brenes, C., García-Cruz, M.I., Gutiérrez-Uribe, J.A., Benadives-Lozano, J.A., Rodríguez-Sánchez, D.G., (2012) inventors; Avomex, Inc., Instituto Tecnologico y de Estudios Superiores de Monterrey, assignees. 2012 Apr 5. Antimicrobial, antibacterial and spore germination inhibiting activity from an avocado extract enriched in bioactive compounds. WO 2012/042404 A2.

Rodríguez-Sánchez, D.G., Pacheco, A., García-Cruz, M.I., Gutiérrez-Uribe, J.A., Benavides-Lozano, J.A., Hernandez-Brenes, C. (2013a) Isolation and structure elucidation of avocado seed (Persea americana) lipid derivatives that inhibit Clostridium sporogenes endospore germination. J. Agric. Food Chem. 61(30) pp. 7403–11. doi: 10.1021/jf401407s.

Rodríguez-Sánchez D, Silva-Platas C, Rojo RP, García N, Cisneros-Zevallos L, García-Rivas G, Hernández-Brenes C. 2013b. Activity-guided identification of acetogenins as novel lipophilic antioxidants present in avocado pulp (Persea americana). J. Chromatogr. B 942–43 37:45. doi: 10.1016/j.jchromb.2013.10.013.

Rodríguez-Sánchez DG, Flores-García M, Silva-Platas C, Rizzo S, Torre-Amione G, De la Peña-Diaz A, Hernández-Brenes C, García-Rivas G. 2015. Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities. Food Funct. 6(1):193–203. doi: 10.1039/c4fo00610k.

Rodríguez-López CE, Hernández-Brenes C, de la Garza RID. 2015. A targeted metabolomics approach to characterize acetogenin profiles in avocado fruit (Persea americana Mill.). RSC Adv 5:106019–29. doi: 10.1039/C5RA22854A.

Rodríguez-Sánchez DG, Pacheco A, García-Cruz MI, Gutiérrez-Uribe JA, Benavides-Lozano JA, Hernandez-Brenes C. 2013a. Isolation and structure elucidation of avocado seed (Persea americana) lipid derivatives that inhibit Clostridium sporogenes endospore germination. J. Agric. Food Chem. 61(30):7403–11. doi: 10.1021/jf401407s.

Salinas-Salazar, C., Hernández-Brenes, C., Rodríguez-Sánchez, D. G., Castillo, E. C., Navarro-Silva, J. M. and Pacheco, A. (2017), Inhibitory Activity of Avocado Seed Fatty Acid Derivatives (Acetogenins) Against Listeria Monocytogenes. J. Food Sci., 82 pp. 134–144. doi:10.1111/1750-3841.13553