Food Specific Natamycin,Antifungal Agent

Natamycin is a polyene macrolide antifungal agent. In food processing, controlling the pH value is one of the important factors to ensure its antibacterial effect. The relevant introduction is as follows:

I. Antibacterial Principle

Natamycin can specifically bind to ergosterol and other sterol groups of fungi to form an antibiotic-sterol complex, thereby changing the permeability of the cell membrane. This leads to the leakage of important substances inside the cell, such as amino acids and electrolytes, and disrupts the normal physiological functions of the cell, thus inhibiting the growth and reproduction of fungi.

II. The Influence of pH Value on the Antibacterial Effect of Natamycin

Acidic Environment: Generally speaking, natamycin has a better antibacterial effect under acidic conditions. When the pH value is in the range of 3 to 6, its solubility is relatively high, and it can better exert its antibacterial effect. Within this pH range, the natamycin molecule can maintain a relatively stable structure and is more likely to bind to the sterols on the fungal cell membrane, effectively inhibiting the growth of fungi. For example, it can play a good antibacterial role in acidic foods such as fruit juices and yogurts, extending the shelf life of these foods.

Neutral and Alkaline Environments: As the pH value rises to the neutral or alkaline range, the antibacterial effect of natamycin will decrease. This is because under neutral or alkaline conditions, its solubility decreases, and the molecular structure may change, weakening its binding ability to the sterols on the fungal cell membrane and thus affecting the antibacterial effect. For example, its antibacterial effect in foods like bread with a pH value of 7 to 8 is relatively slightly worse compared to that in acidic foods.

III. Methods of Controlling pH Value in Food Processing

Selecting Appropriate Raw Materials: Some food raw materials themselves have a certain degree of acidity or alkalinity. Selecting appropriate raw materials can initially adjust the pH value of the food. For example, using fruit juices with strong acidity or fermentation agents can reduce the pH value of the food, making it more conducive for natamycin to exert its antibacterial effect.

Adding pH Regulators: Commonly used pH regulators include acidic substances such as citric acid, malic acid, and lactic acid, as well as alkaline substances such as sodium carbonate and sodium bicarbonate. According to the characteristics of the food and the suitable pH range for the action of natamycin, accurately add an appropriate amount of pH regulators to control the pH value of the food within a suitable range. For example, when making cheese, an appropriate amount of citric acid can be added to reduce the pH value and enhance the inhibitory effect of natamycin on fungi in the cheese.

Controlling the Change of pH Value During the Processing: During the food processing, some operations may cause changes in the pH value, which need to be controlled. For example, the metabolic activities of microorganisms during the fermentation process may produce acidic or alkaline substances, affecting the pH value of the food. At this time, the change of the pH value can be adjusted by controlling the fermentation conditions, such as temperature, time, and ventilation, to ensure that natamycin can maintain a good antibacterial effect throughout the processing.

In food processing, it is necessary to reasonably control the pH value according to the specific types of food and the characteristics of natamycin to fully exert the antibacterial effect of natamycin and ensure the quality and safety of food.