Pimaricin, natamycin (E235)

One of the most famous and most harmless food preservatives is natamycin, another name for which is pimaricin, or food additive E235. By nature, it is a powerful antibiotic of natural origin. The synthesis of a substance occurs in the process of vital activity of certain types of microorganisms.

Natamycin is a substance with a pronounced anti-mold and antifungal property, recognized as safe for humans at the world level. Even at low concentrations, this nutritional supplement is able to inhibit the growth and development of a wide range of known fungi, yeasts and molds, while not affecting beneficial microorganisms. Due to this specificity of action, pimaricin is known as a popular ingredient in cheeses and processed meat products. But the food industry is not the only industry in which the additive has found application.

Chemical characteristics of natamycin, its origin

The substance belongs to polyene antifungal agents of the macrolide type. In appearance, it is a white or cream-colored crystalline powder that has no taste or smell. The preservative is very poorly soluble in water, forming an inhomogeneous turbid white suspension, and does not dissolve in most organic solvents. It has good solubility in alcohols, as well as in the presence of a small amount of demethyl sulfoxide or glacial acetic acid.

The solubility of a substance varies greatly depending on the level of acidity: at a pH level of 3 to 9, it greatly increases, while its activity against microorganisms decreases.

At room temperature, natamycin is highly stable, which can be further enhanced by increasing humidity levels. In the dry state, the active powder can withstand temperatures up to 100 degrees Celsius, but for a short time. However, if the substance is exposed to temperatures above 50 degrees for longer than 24 hours, its activity decreases.

The level of acidity affects not only the solubility, but also the strength of action of pimaricin – at a pH level of 5-7 it will be the most powerful, from 3 to 5 or from 7 to 9 – it weakens by 8-10 percent. If the pH is more than nine or less than three, the activity of the preservative drops by about 30 percent.

In addition, the additive is also sensitive to sunlight: exposure to it can reduce its activity.

E235 can react with various oxidants, such as peroxide or chlorine dioxide, as a result of which its effect is weakened. In this case, manufacturers use antioxidants like vitamin C.

The stability of the component may be affected by certain heavy metals such as nickel, lead, mercury or iron. This factor must be taken into account when choosing a packaging for storing a substance.

The E235 additive is obtained microbiologically by fermenting it from cultures of streptomycete mold fungi. The resulting active substance is concentrated, crystallized, then dried and, usually in a ratio of 1/1, mixed with lactose, which plays the role of a neutral carrier.

The most basic property is antifungal and preservative, which is why it is used as a preservative in various industries. A preservative extends the shelf life of finished products or raw materials.

The mechanism of action of the substance

As an antibiotic, natamycin is about 500 times more potent than sorbic acid. Most harmful microorganisms are affected by the additive diluted to a concentration of 1-6 parts per million. Literally several types of mold require a higher concentration of the active substance – 1-10 parts per million.

The antibiotic acts on the sterols in the cell wall of fungi or mold, binding them and thereby causing membrane malfunction. As a result, the cell loses important metabolites and dies. It is for this reason that the substance does not act on bacteria – there are no sterols in the walls of their cells.

The use of natamycin in the food industry

Along with the pharmaceutical industry, the food industry consumes a significant amount of the produced E235 preservative. The main areas of application of the additive:

• surface treatment and spraying of whole and sliced ​​cheeses;
• surface treatment of fish and meat products;
• addition to dairy products (yogurt, cream cheese, sour cream);
• adding to the pulp of fruits and fruit juices;
• use in the process of cooking canned dairy products, fish raw materials, caviar, minced meat, fish pastes.

Technologies for the use of natamycin for cheese processing

In the process of making cheeses, the component is practically indispensable: it is used to suppress mold in mature cheeses. At the same time, natamycin cannot be applied directly to the raw material; only the surface of the product can be treated with it.

The main advantage of the substance over other types of preservative is that it is able to destroy mold microorganisms on the surface of the cheese, without in any way affecting the process of its bacterial maturation.

There are several ways to process cheese products:

• adding 0,05% natamycin to the composition of the shell;
• immersion of salted cheese in the liquid form of the substance at a concentration of 0,05-0,28% for a short period of time (no more than 4 minutes);
• spraying a suspension of a similar concentration onto the cheese casing or the product cut into pieces.

The result of the use of the substance is an increase in the yield of finished products without traces of harmful microorganisms and spoilage of the cheese that they cause, as well as an improvement in the appearance and quality of the product, and an extension of its shelf life.

The brine used for dipping cheeses may also contain pimaricin. 1-30 grams of preservative are added per 50 ton of liquid. Such an amount, firstly, is sufficient to suppress the growth and development of harmful fungi and mold, and secondly, it meets international requirements regarding the content of the E235 additive in food. To maintain the concentration of the substance in the future, every 2 weeks another 10 g of natamycin is added per 1 ton of brine.

Surface treatment occurs with the help of a suspension, which is prepared in this way: 2-4 g of preservative is added to 1 liter of water with a temperature of not more than 15 degrees Celsius. The head of cheese is dipped into the resulting liquid, dried and packaged.

Such an aqueous solution can be sprayed on the surface of cheeses, which allows you to extend their shelf life.

An important technological requirement in the process of making cheese is that pimaricin should not penetrate deeper than 5 mm into it.

How is preservative E235 used for meat and fish

Products are processed similarly to cheese – they can be dipped in a suspension of natamycin or sprayed, and the shell can also be processed by soaking in a solution of the substance. The permissible concentration of the additive is not more than 4 mg per 1 cm XNUMX. Thus, it is possible to save such food from the formation of mold and the reproduction of fungi:

• sausages and sausages;
• dried, dried fish;
• grilled meat;
• smoked meat, poultry and fish.

The most common method of “preserving” sausages and frankfurters from the harmful effects of microorganisms is casing processing. Thanks to this technology, the antibiotic does not get deep into the food. The shells are soaked in a suspension of the additive, which settles on their surface. As a result, spoilage of the product above and below the casing is prevented. Shells of natural origin are soaked for about 2 hours, synthetic – from 20 to 60 minutes.

Dipping of freshly prepared sausages takes place in a suspension with a temperature of 20-30 degrees Celsius. The concentration of the solution is not more than 2 g of natamycin per liter of water, in addition, sodium chloride (8-10%) is added to it. For spraying, a more concentrated mixture is used – 3-4 g of active ingredient per 1 liter of water. Sodium chloride is also used here.

Other products in which the additive E235 may be found

In addition to cheeses, sausages and sausages, the preservative is used to process:

• soy sauces (concentration of 15 particles per 1 million reliably protects the product from mold processes);
• bakery products (a suspension of 150-200 ppm is applied to the surface of finished products or raw dough);
• fruit juices (in apple, grape, tomato, orange juices, the substance inhibits the fermentation process and prevents the reproduction of yeast);
• canned foods;
• vinegar, beer, wine (suppresses the growth and reproduction of yeast and mold);
• confectionery.

Another area in which natamycin cannot be dispensed with is pharmaceutical. This substance is active in various medical preparations aimed at treating various forms of fungal diseases, and is used in ointments, creams, suppositories and tablets.

Benefit and harm to humans

According to the results of scientific research, the E235 additive does not have a toxic effect on the human body. The main spectrum of its action is the fight against fungal diseases:

• fungal otitis;
• candidiasis of the skin and nails;
• intestinal candidiasis;
• diseases of the oral cavity associated with the activity of fungi;
• thrush.

To date, there is no officially confirmed data on the possible oncogenicity or mutagenicity of the substance. The only danger that it can pose is the negative consequences of an overdose.

The normal daily dose of pimaricin is 0,3 mg per 1 kilogram of adult weight.

The concentration of the additive in food products is insignificant, and it is almost impossible to get a dose exceeding the norm with them, which cannot be said about medicines. An amount of more than 500 mg per 1 kg of body can have a poisoning effect with corresponding symptoms – nausea, vomiting, diarrhea. In this case, it is necessary to wash the stomach of the victim, in severe cases, seek medical help.

It should also be taken into account that the substance is an antibiotic, and its entry into the body, including with food, can adversely affect the microflora of the stomach and intestines, causing disturbances in their work. For these reasons, children are not recommended to eat food with an additive in the composition. With caution, it should be treated by people with diseases of the digestive tract.

Natamycin is not only a food preservative, but a powerful antibiotic, a means to combat fungal and mold microorganisms. It should be noted that a number of states of the European Union, the USA and Canada have banned the use of the E235 additive in food products within their territories. There is no such ban in Ukraine and Russia, so the production of cheeses, sausages, canned food, juices, confectionery products, alcoholic beverages like fruit or berry wine and beer often resorts to its help to prevent food spoilage. The spectrum of action of pimaricin is fungi, yeast and mold cultures, while it has no effect on bacteria, so it cannot interfere, for example, with cheese ripening processes. In small doses, the food preservative E235, in general, does not harm a person and is not hazardous to health.

The pharmaceutical industry uses natamycin as the active ingredient in some antifungal drugs, some of the most popular being Pimafucin and Ecofucin. With their help, candidiasis, fungal otitis media and other fungal infections of the skin, nails and mucous tissues are treated. The additive has shown itself to be a powerful antibiotic with a depressing effect on pathogens.