The leaves of the plant that yields carob, a substitute for chocolate, are a rich source of antibacterial substances. These substances can fight the bacterium responsible for the food poisoning disease listeriosis.
Carob is a substitute for chocolate that does not contain caffeine or theobromine, which means that it can be given to animals as well as being used as a chocolate substitute by people. Carob is typically dried or roasted, and is mildly sweet. In powdered, chip, or syrup form it is used as an ingredient in cakes and cookies.
Carob may, according to new research, have anti-bacterial properties and these could be harnessed to protect foods from microorganisms that cause food poisoning. The research was undertaken at the Department of Life and Environment Sciences of the University of Cagliari.
According to the research brief, the research team undertook tests in which extracts of carob leaves were used to challenge the food poisoning bacterium responsible for listeriosis: Listeria monocytogenes. L. monocytogenes is a bacterium responsible for causing food poisoning and the microbe has been responsible for several major incidents.
So far this year, there have been 20 cases of listeriosis and 4 deaths linked to imported Frescolina Marte Brand Ricotta salata cheese. Last year, 147 persons were infected with listeria and 33 died due to the infection that was linked to whole cantaloupes from Jensen Farms, Colorado, according to the CDC.
The studies proved effective in inhibiting the growth of Listeria bacteria growing in laboratory cultures. The results were promising enough for the scientists to plan further tests of carob extracts on Listeria growing in meat and fish
As PhysOrg notes, the increase in antibiotic-resistant bacteria has led to a renewed search for new natural substances to preserve food and control disease-causing bacteria. The use of carob is one of a number of natural substances being investigated.
The research team was led by Nadhem Aissani. The findings have been published in the ACS Journal of Agricultural and Food Chemistry. The reference is:
Nadhem Aissani et al. Inhibitory Effect of Carob (Ceratonia siliqua) Leaves Methanolic Extract onListeria monocytogenes. Journal of Agricultural and Food Chemistry, 2012; 60 (40): 9954