Food poisoning by biogenic amines

Overview

The biogenic amines are non-volatile amines which comes from the microbial degradation of foods rich in proteins (putrefaction of meat / fish, cheese maturation, various fermentations), following the decarboxylation of amino acids (Figure 1). This reaction is catalyzed by enzymes (decarboxylases) present in some bacteria (Proteus morganii, Escherichia coli, Lactobacillus Bulgarian, ...).

Biogenic amines are normal metabolites of plants, animals and microorganisms. Thus one finds histamine, low dose, in the tomato and spinach. However, the microbial contamination of food results in excessive production of biogenic amines, which leads to food poisoning after ingestion of these commodities.

Major biogenic amines

The main biogenic amines found in foods are histamine, tryptamine, tyramine, the putrescine, cadaverine of the spermidine and spermine (Table 1). However, histamine is by far the most studied amine and probably the most vulnerable.

Parameters affecting the production of biogenic amines

The production of biogenic amines in foods is influenced by the nature of microorganisms, the presence of substrate and the characteristics of the environment (temperature, pH and salinity).

Microorganisms

Many microorganisms are responsible for production of biogenic amines. In the case of histamine, bacterial species capable of producing large quantities of histamine in tuna are essentially Proteus morganii, Klebsiella pneumoniae and Enterobacter aerogenes.

Substrate

The formation of biogenic amines from the decarboxylation of free amino acids. These are either naturally present in food costs (the Scombridae, for example, contain more than 2% of free histidine) or the decarboxylation protein (proteolysis).

Effect of environment

The environmental parameters that affect the formation of biogenic amines in particular, temperature, pH and salinity.

The optimum temperature for the production of biogenic amines is 20 to 37 ° C. Apart from these values, the production of biogenic amines decreases as one approaches 5 ° C (as minimum) and 40 ° C (like most). At temperatures negative (<0 ° C), there is no production of biogenic amines.

The pH optimum decarboxylase enzyme activity is between 5 and 6.5.

The salinity of the environment has a significant effect on both the growth of bacteria responsible for the production of enzymes and the decarboxylase activity of decarboxylases themselves. In the case of histamine, the optimal salinity of the training is 1 to 3% NaCl.

Responsible food

The biogenic amines are present in all foods that have undergone processes of putrefaction and fermentation uncontrolled.

The foods most often complained of having caused poisoning are the most spectacular fish products: sardines, anchovies, pilchards and especially Scombridae (tuna, bonito, mackerel, ...). Therefore histamine poisoning has been called "poisoning the Scombridae" or "intoxication scombroides.

It was also detected the presence of biogenic amines in cheese (Swiss cheese, Gruyere, Emmental). These products have sometimes been reported to cause food poisoning due mainly to the existence of a high histamine, but also to the presence of other biogenic amines such as tyramine, tryptamine, the cadaverine and putrescine.

Other foods, like meat products and fermented beverages may also contain a quantity more or less important biogenic amines. However, these foods have not been associated with poisoning by biogenic amines.

Threshold of toxicity and symptoms

Information on this title refers only to histamine. For other biogenic amines, it has not yet established a threshold of toxicity, but admit they potentiate the effect of histamine.

Toxicity threshold

The threshold of toxicity is very difficult to establish because of considerable variability due to different factors (age, sex, health status, effectiveness of detoxification). It is accepted that histamine levels below 50 ppm have no effect. Whereas values between 50 and 100 ppm, mild clinical signs appear. While histamine concentrations above 100 ppm, the product is considered toxic.

In the case of canned fish, the standard used for histamine is often 100 ppm as the limit allowed. However, this threshold may vary from one country to another and can go up to 500 ppm

Symptomatology

Symptoms of histamine poisoning appear after an incubation period of a few short minutes to several hours. They are related to the vasodilator effect of histamine (capillary dilation) causing the phenomena of high blood pressure and hemoconcentration causing cutaneous signs (facio-cervical redness, swelling, hives, burning sensation) and headache, tachycardia, vomiting and diarrhea may be observed.

Preventive measures

The biogenic amines are generally thermostable, as is the case of histamine, the cadaverine, the putrescine, of the tyramine and spermidine. Thus, the only means of prevention is to limit the proliferation of microorganisms responsible for their training and through rigorous monitoring of the cold chain (storage temperature <5 ° C) and the conditions of hygiene.