What Is Natamycin?

Natamycin-nearly white or cream yellow crystalline powder. It is a odorless, tasteless, low-dose and highly safe food preservative. Natamycin (Natamycin) is a white to milky white odorless and odorless crystalline powder produced by the controlled fermentation of Streptomyces catarrhalis, which usually exists in the enol structure. Its mechanism of action is that it combines with ergot sterol and other sterol groups of fungi to block the ergosterol biosynthesis, thereby distorting the cell membrane and eventually causing leakage and cell death. Surface treatment of dough with natamycin in baked goods can significantly extend the shelf life.

Chinese name: Natamycin
Foreign name: Natamycin

Molecular formula: C33H47NO13
Molecular weight: 665.73

About Natamycin

Molecular formula

C ₃₃ H ₄₇ NO ₁₃ with a molecular weight of 665.73 ^[1] .
English name: Natamycin

Chinese name: Natamycin

Molecular formula: C ₃₃ H ₄₇ NO ₁₃

Quality standard: Hygienic standard for the use of natamycin (GB 2760-2010); FDA § 172.155, 2000

Molecular structure: Polyolefin macrolide, tetraene system is all-cis, C ₃ ~ C ₉ on the lactone ring is a hemiacetal structure, contains a carbohydrate group connected by a glycosidic bond, namely amino dideoxymannose ^[2] .

Ionization constant: Natamycin is an amphoteric substance with pK _a values of 4.6 and 8.35, and its isoelectric point is 6.5

Melting point: 280 ° C

Solubility: slightly soluble in water, hardly soluble in most organic solvents. The solubility in water at room temperature is 30 ~ 100mg / L. When the pH is lower than 3 or higher than 9, the solubility will increase, but the stability of natamycin will be reduced.

Natamycin is a natural antifungal compound produced by the fermentation of streptomyces. It belongs to polyene macrolides. It can widely and effectively inhibit the growth of various molds and yeasts, and it can also inhibit mycotoxins. It can be widely used in food preservation and antifungal treatment. Natamycin has no inhibitory effect on bacteria, so it does not affect the natural maturation process of yogurt, cheese, raw ham, and dry sausage.

Natamycin mechanism of action

Natamycin relies on its lactone ring structure to interact with sterol compounds on the cell membrane of the fungus to form an antibiotic-sterol compound, thereby destroying the structure of the fungal cell plasma membrane. The hydrophilic part of the macrolide (polyol part) forms water pores on the membrane, which impairs the permeability of the cell membrane, and then causes the exudation of amino acids, electrolytes and other substances in the bacteria, resulting in the death of the bacteria. When there is no sterol compound on the cell membrane of some microorganisms, natamycin has no effect on it, so natamycin only inhibits fungi and does not have antibacterial activity against bacteria and viruses ^[2] .

Natamycin safety

1. ADI (Acceptable Daily Intakes) 0 ~ 0.3mg / kg (FAO / WHO, 1994)

2. Safe to apply on food (FDA, §172.155, 1994)

3. LD ₅₀ 2.73g / kg (experiment with matured male mouse)

In June 1982, the US FDA officially approved natamycin as a food preservative. In 1996, the China Food Additive Standard Chemical Technology Committee officially approved natamycin as a food preservative. The Joint FAO / WHO Committee of Experts on Food Additives stipulates that the human body can unconditionally accept 0.3 mg of natamycin per kilogram of body weight per day. JECFA / EC also authorizes approval. The human body usually consumes far less than the safe amount, even for cheeses and sausages which are consumed in large quantities ^[3] .

The national standard GB2760 stipulates the applicable scope and dosage of natamycin: cheese, meat products, broth, western-style ham, Cantonese-style moon cakes, pastry surface, etc., sprayed or soaked with 200-300mg / kg suspension. The residual amount should be less than 10 mg / kg ^[4] .

Natamycin advantages

Natamycin as a microbial preservative has attracted much attention due to its safety, natural and healthy characteristics. Natamycin has many advantages: it extends the shelf life of food and prevents spoilage caused by yeast and mold;

Reduce food recycling due to spoilage and reduce production costs;

Meet consumer requirements for natural food;

Does not change the flavor of the food;

Low dose and high efficiency;

Long antibacterial effect.

Natamycin Food Uses

Natamycin is a natural, broad-spectrum, highly efficient and safe yeast and fungal inhibitor of filamentous fungi. It can not only inhibit fungi, but also prevent the production of mycotoxins. Natamycin is not harmful to the human body, it is difficult to be absorbed by the human digestive tract, and it is difficult for microorganisms to develop resistance to it. At the same time, because of its low solubility, it is usually used for food surface preservation. Biological preservatives.

cheese

Natamycin prevents the cheese from moulding when it matures, limiting the formation of mycotoxins. Because it is difficult to penetrate the cheese and stay only on the surface of the cheese, it is advantageous to control the growth of mold on the surface of the cheese, and it does not affect the ripening process of the cheese. There are three specific application methods: 1). 0.05% 0.28% Natamycin is sprayed on the surface of cheese products 2). Soak the salted cheese in 0.05% 0.28% concentration suspension for 2 4 minutes. 3 Add 0.05% natamycin to the cheese-covered coating.

Cantonese moon cake

Moon cakes are nutritious, and crusts and salted egg yolks often mold. Natamycin has a good anti-mildew effect on moon cakes. Spraying method is generally used when using: Natamycin product is formulated into a suspension of 0.02% to 0.04%. When the moon cake is baked and cooled to normal temperature, spray the suspension of Natamycin around the surface and bottom of the moon cake to complete. Exterior mildew proof. Raw salted egg yolks are roasted in the oven until seven or eight are mature. After cooling out, immerse them in Natamycin suspension for about 2 minutes to prevent mildew of the yolk filling.

Bakery

Spraying 100 ~ 500ppm Natamycin solution on the surface of baked foods such as cakes, white bread, and shortbread, or spraying Natamycin on the surface of unbaked dough, its anti-mildew effect is very good. Does not affect the taste of the product.

Meat products

The method of soaking or spraying meat foods can achieve safe and effective anti-mildew purpose when using 4 mg / cm2 natamycin. Soaking the casing with a natamycin suspension at a concentration of 0.05% to 0.2% (w / v), or used to soak or spray the filled sausage surface can effectively prevent mold growth on the sausage surface. Grilled products such as barbecue and roasted duck, dried fish products, etc., can also be sprayed with Natamycin suspension of 0.05% ~ 0.1% (w / v) concentration to extend the shelf life of the product.

Salad dressing

Salad dressing is a high-fat food, and mildew often occurs after the summer. It is reported in the literature that 10 ppm natamycin was added to salad dressing, no deterioration was found during the test, and the number of microorganisms did not change significantly. Salad dressing is similar to cheese and has a high fat content. Tests show that natamycin has a good antibacterial effect on high-fat foods.

soy sauce

In summer when the room temperature is high, adding 15 ppm of natamycin to soy sauce can effectively inhibit the growth and reproduction of yeasts and prevent the appearance of white flowers. The combination of natamycin and nisin can be used in soy sauce to prevent mildew, which can more effectively inhibit bacteria and reduce the concentration of bacteria.

Drink

Due to the high sugar content and organic acid content of various fruit juices, they are very suitable for the growth and reproduction of yeasts, causing the spoilage of fruit juices. The use of natamycin can increase the storage stability of non-alcoholic beverages. The application of 20 ppm natamycin in grape juice can prevent the fermentation of fruit juice caused by yeast contamination, and the addition of 100 ppm can completely stop the fermentation activity. Orange juice is generally contaminated by fungi under natural conditions. Orange juice usually deteriorates after one week of storage. After adding natamycin, even if the dosage is as low as 1.25ppm, it can be stored at 2 4 for a shelf life of 8 weeks. . The bacteriostatic effect of natamycin has a certain relationship with the storage temperature. Concentrated orange juice stored at 10 can inhibit the growth of yeast in 10ppm; when stored at room temperature, 20ppm natamycin is required for bacteriostatic effect. Apple juice 30ppm natamycin can prevent the fermentation of apple juice for up to 6 weeks, and the original flavor of the juice will never change. Natamycin at a concentration of 70 mg / kg in tomato juice has a good anti-mildew effect on tomato juice.

other

The use in rice cakes and steamed buns can prevent mildew and effectively extend the shelf life. Natamycin is used in condiments such as vinegar to prevent deterioration caused by mold and yeast. In beer and wine, 2.5 mg / kg of natamycin can greatly extend the shelf life. In addition, adding 5 to 10 ppm of natamycin to yogurt can extend the shelf life of the product for more than 4 weeks.

Natamycin for medical use

Natamycin is used to treat fungal infections, including Candida, Aspergillus, Fusarium, etc. It is also used as eye drops or oral medicaments. In these applications, the human body has less absorption of Natamycin. When taken orally, it is not substantially absorbed from the gastrointestinal tract, making it unsuitable for systemic infections. Natamycin is also used in eye drops, and its 5% natamycin content is suitable for the treatment of fungal blebitis, conjunctivitis and keratitis caused by microorganisms, including Fusarium keratitis.