The recent recall of some jars of Sicilian pesto is worth bringing attention back to the botulinum, a pathogenic bacterium Very dangerous to keep away from. Here’s how.
Botulinum, a dangerous pathogenic bacterium
Clostridium
botulinum
– in jargon, botulinum-is an anaerobic bacterium capable of producing extremely heat-resistant spores and toxins with neurotrophic activity.
Botulism is the most severe food poisoning known to each other. The neurotoxins produced by the Clostriudium
botulinum
are indeed capable of blocking the activity of motor neurons, resulting in flaccid paralysis of various muscle districts.
Paralysis has a downward trend, with initial involvement of the eye muscles and subsequent visual disturbances (diplopia, or double vision). Which is followed by paralysis of the muscles of swallowing and speech, loss of coordination of movements, and paralysis of the upper and lower limbs. In patients not receiving prompt intensive care, paralysis of the diaphragm and respiratory muscles can cause death.
Botulinum, where it is found
Foods of plant origin
can become contaminated with spores of
Clostridium
botulinum, which have ubiquitous distribution in topsoil, soil and dust (as well as on the sea and lake bottoms, and in the intestines of many mammals and fish). Potting soil in particular can be rich in spores that remain on products if not thoroughly washed.
Vegetable preserves homemade (e.g. mushrooms, eggplant, olives,
etc
.) can be dangerous when they have not been subjected to suitable temperatures to destroy the spores of
Clostridium
botulinum. The subsequent addition of oil creates the necessary environment (anaerobiosis) for the development of the microorganism, which germinates from the spore and produces the neurotoxins.
Some meat products (Ex. Salami, cooked hams, mortadella, sausages
etc
.) could themselves be at risk if not properly treated with sodium or potassium nitrites or nitrates. B
otulinum
is derived from the Latin
botulus
, sausage. The first, often fatal, cases of botulinum intoxication were reported following the consumption of pork sausages where clostridium could develop. And it was precisely to prevent this risk that the use of the aforementioned preservatives was introduced.
Industrial productions are generally safe because self-control and HACCP programs devote primary attention to the risk under consideration. The rare cases of food product recalls for botulinum contamination-as recently occurred on some packages of Sicilian fennel and almond pesto produced by Frantoi Cutrera-are the (no less dangerous) exceptions that confirm the rule.
Botulism, how to eliminate the risk?
Nearly extreme conditions of temperature and acidity-that is, the use of preservatives, in meat products-are the only guarantees.
1) Temperature. Clostridium spores are destroyed by exposure to the temperature of 121 °C for the duration of 3 minutes. Botulinum toxins are inactivated at a temperature of 80 °C for at least 10 minutes.
2) Acidity. Only conditions of high acidity (pH below 4.6) can hinder clostridium development and botulinum toxin production.
3) Preservatives. Nitrites and nitrates prevent spore germination and the subsequent development of Clostridium
botulinum
on various meat products (e.g., salami, cooked hams, mortadella, sausages etc.).
In contrast, the peasant legend that chili pepper is also suitable for inhibiting the development of Clostridium botulinum is without any basis. Conversely, very serious cases of botulism have also been reported following consumption of hot peppers in oil.
Silvia Bonardi and Dario Dongo
Graduated in Veterinary Medicine and Specialist in Inspection of Food of Animal Origin and in Veterinary Public Health, she is Professor of Inspection and Control of Food of Animal Origin at the University of Parma.
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
