A new study that has been published in the Journal of Agricultural and Food Chemistry of the American Chemical Society (ACS for its acronym in English), has found that the leaves of the tree Ceratonia siliqua, popularly known as carob tree, contain antibacterial substances capable of inhibit the proliferation of bacteria such as Listeria monocytogenes, responsible for listeriosis, a severe food poisoning.

And although human beings have been using plants for medicinal purposes for centuries, there are still many preventive and curative properties of the plant species to be discovered and exploited. In this case, the team of researchers led by Nadhem Aissani, sought to find a natural substance that would serve to conserve food and prevent the proliferation of microorganisms harmful to health, as more and more bacteria resistant to antibiotics, and is necessary find alternatives to fight them.

Extracts of the leaves of the carob tree prevented the growth of Listeria monocytogenes -bacteria responsible for listeriosis- in laboratory cultures

To carry out the research, they collected carob leaves, dried them in a dark place at room temperature, and then stored them in paper bags that they sealed and stored also in the dark and at room temperature. Later they used an extract of these leaves with different strains of microorganisms, such as Salmonella, Escherichia coli or Listeria monocytogenes to check its antibacterial effects.

The researchers observed that the extracts of the leaves of the carob tree prevented the growth of Listeria monocytogenes in laboratory cultures. Now, they want to perform new tests to see if they get the same results with meat and fish samples.

The leaves, bark and fruits of the carob tree are already used in the cosmetics and textiles industry, and also to make a chocolate substitute - carob - that lacks caffeine and theobromine (substances that chocolate does contain), and It is considered very healthy. But if its antibacterial properties are confirmed, it would also serve to develop a totally natural antimicrobial product.

Introduction and Part 1 - Hawthorn - Amanda McQuade Crawford (November 2019).