The role of preservatives is affected by food raw materials and various ingredients in food. Some components in food, such as spices, seasoning agents and emulsifiers, have antibacterial effects, or some components can selectively have physical and chemical interactions with preservatives, which will affect the use effect of preservatives to varying degrees.

Among the food ingredients that have a general impact on food additives and preservatives are salt, carbohydrates and alcohol, which can reduce the activity of enzymes in microorganisms. The above two points are also conducive to preservatives. However, salt can also change the distribution coefficient of preservatives and make their distribution uneven. Therefore, it may have an adverse impact on the anti-corrosion effect. The sugar in carbohydrates is itself a nutrient source of microorganisms, which can promote the growth of microorganisms when the concentration is appropriate, but the effect of sugar on the partition coefficient is generally lower than that of salt. Alcohol is a bactericide at a higher concentration, and has antibacterial effect at a low concentration. Generally, alcohol can enhance the role of preservatives.

Special attention should be paid to the chemical reaction between ingredients in food and preservatives, which may make preservatives partially or completely ineffective, or produce side effects, such as SO2 and sulfite reacting with aldehydes, ketones and sugars in food, and nitrite may produce toxic nitrosamines. Therefore, relevant information should be consulted before using preservatives.

Preservatives can also be decomposed by microorganisms in food, especially organic preservatives, which may even become a carbon source for microorganisms. For example, sorbic acid can be reduced to sorbitol by lactic acid bacteria, so if used improperly, preservatives are not only ineffective, but also may be used by microorganisms.

In short, the food additives and ingredients research group of East China University of science and technology believes that once the microorganisms in food begin to function, even if preservatives are added to stop the corruption and deterioration, the food will not be able to return to the sensory freshness. Therefore, no matter how effective the preservative is, it must be under a very good hygienic condition at the beginning of food processing, which is also one of the principles of preservative use.