One of the most well-known and most harmless food preservatives is natamycin, another name for which is pimaricin, or food supplement E235. By nature, it is a powerful natural antibiotic. Synthesis of substances occurs in the process of life of certain types of microorganisms.
Natamycin is a substance with a pronounced anti-mold and antifungal properties, recognized at the world level as safe for humans. Even at low concentrations, this dietary supplement is able to inhibit the growth and development of a large range of known fungi, yeasts and molds, without affecting beneficial microorganisms. Because of this specific action, pimaricin is known as a popular component of cheeses and processed meat products. But the food industry is not the only industry in which the additive was used.
Chemical characteristics of natamycin, its origin
The substance is a macrolide type polyene antifungal. 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 a non-uniform turbid suspension of white color, 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 demetyl sulfoxide or glacial acetic acid.
The ability to dissolve the substance varies greatly depending on the level of acidity: when the pH level is from 3 to 9, it increases very much, while its activity towards microorganisms decreases.
At room temperature, natamycin is highly resistant, which can be further enhanced by increasing the humidity level. 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 of more than 50 degrees longer than 24 hours, its activity decreases.
The level of acidity affects not only the solubility, but also the strength of the effect of pimaricin - at pH levels of 5-7, it will be most powerful, from 3 to 5 or from 7 to 9 - weakens by 8-10 percent. If the pH is more than nine or less than three, the activity of the preservative action drops by about 30 percent.
In addition, the additive is sensitive to sunlight: their effects can reduce its activity.
E235 can react with various oxidants, for example, peroxide or chlorine dioxide, as a result of which its action diminishes. In this case, manufacturers use antioxidants like vitamin C.
The stability of the component may be affected by certain heavy metals: nickel, lead, mercury or iron. This factor must be considered when choosing a package for storing a substance.
Supplement E235 is obtained by microbiological method, fermenting it from cultures of mold fungi streptomycetes. The resulting active ingredient 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, therefore it is used as a preservative in various industries. Preservative prolongs the shelf life of the finished product or feedstock.
Mechanism of action of a substance
As an antibiotic, natamycin is about 500 times stronger than sorbic acid. Most harmful microorganisms are susceptible to an additive diluted to a concentration of 1-6 parts per 1 million. Literally several types of mold require a higher concentration of the active substance - 10-25 ppm.
The antibiotic acts on sterols in the cell wall of fungi or mold, binding them and, thereby, causing disruptions in the functioning of the membrane. As a result, important metabolites are lost in the cell and it dies. For this reason, the substance does not act on bacteria - sterols are absent in the walls of their cells.
Use of natamycin in the food industry
Along with the pharmaceutical industry, the food industry consumes a significant amount of the E235 preservative produced. The main application areas of the additive:
- surface treatment and spraying of whole and sliced cheeses;
- surface treatment of fish and meat products;
- adding to dairy products (yogurt, cream cheese, sour cream);
- making fruit pulp and fruit juices;
- use in the process of cooking canned dairy products, fish raw materials, caviar, minced meat, fish pastes.
Technologies for using natamycin to process cheeses
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 can not be applied directly to the raw materials; they can only process the product surface.
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 affecting the process of its bacterial ripening.
There are several ways to handle cheese products:
- adding 0.05% natamycin to the shell;
- immersion of salted cheese in the liquid form of the substance in a concentration of 0.05-0.28% for a short period of time (not more than 4 minutes);
- spraying a suspension of a similar concentration onto a cheese casing or sliced product.
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 they cause, as well as an improvement in the appearance and quality of the product, an extension of its shelf life.
The pickle used for cheese dipping may also contain pimaricin. 30-50 grams of preservative are added to 1 ton of liquid. This amount is, firstly, sufficient to suppress the growth and development of harmful fungi and mold, and secondly, it complies with international requirements regarding the content of E235 additive in food. To maintain the concentration of the substance in the future, every 2 weeks another 10 g of natamycin is added to 1 ton of brine.
The surface is treated with 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 in the resulting liquid, dried and packaged.
Such an aqueous solution can spray the surface of the cheese, which allows to extend their shelf life.
An important technological requirement in the process of making cheese - pimaricin should not penetrate into it deeper than 5 mm.
How to apply the preservative E235 for meat and fish
Products are processed in the same way as cheese - they can be dipped into natamycin suspension or sprayed, and it is also possible to process the shell by soaking the substance in solution. The permissible concentration of the additive is not more than 4 mg per 1 cm. In this way, such food can be preserved from the formation of mold and the growth of fungi:
- sausages and sausages;
- dried, dried fish;
- grilled meat;
- smoked meat, poultry and fish.
The most common method of "preserving" sausages and sausages from the harmful effects of microorganisms - the treatment of the shell. Thanks to this technology, the antibiotic does not get deep into the food. The shells are soaked in a suspension of the additive, which is deposited on their surface. As a result, product damage on top of and below the shell is prevented. Shells of natural origin are soaked for about 2 hours, synthetic - from 20 to 60 minutes.
Dipping freshly cooked sausages occurs in 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 apply a more concentrated mixture - 3-4 g of active ingredient per 1 liter of water. Sodium chloride is also used here.
Other products in which E235 can be found
In addition to cheeses, sausages and sausages, a 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 parts per million process 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 yeast from multiplying);
- canned foods;
- vinegar, beer, wine (suppresses the growth and reproduction of yeast and mold);
Another area in which natamycin can not be dispensed with is pharmaceutical. This substance is active in various medical preparations aimed at the treatment of various forms of fungal diseases, and is used in ointments, creams, suppositories and tablets.
The benefits and harm to humans
According to the results of scientific research, 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 media;
- skin and nail candidiasis;
- intestinal candidiasis;
- diseases of the oral cavity associated with the activity of fungi;
To date, there are no officially confirmed data on the possible oncogenicity or mutagenicity of a substance. The only danger it may pose is the negative effects 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 is insignificant, and it is almost impossible to get a dose that exceeds the norm with them, which cannot be said about drugs. An amount of more than 500 mg per 1 kg of the body can have the effect of poisoning with the 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 the additive in the composition. Caution should be applied to people with diseases of the digestive tract.
Natamycin is not only a food preservative, but a powerful antibiotic, a means to fight against fungal and moldy microorganisms. It should be noted that a number of states of the European Union, the USA and Canada have banned the use of E235 in food products within their territories. There is no such ban in Ukraine and Russia, so the production of cheeses, sausages, canned foods, 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 - fungi, yeast and mold cultures, while the bacteria it has no effect, so it can not interfere, for example, the process of maturation of cheese. In small dosages, the food preservative E235, in general, does not cause harm to a person and is not hazardous to health.
The pharmaceutical industry uses natamycin as an active ingredient in some antifungal drugs, some of the most popular are Pimafucin and Ecofucin. With their help, candidiasis, fungal otitis and other fungal infections of the skin, nails and mucous tissues are treated. The additive has proven to be a powerful antibiotic with a depressant effect on pathogens.