The role of preservatives is affected by the food raw materials and various components of the food, certain components of the food such as spices, flavoring agents and emulsifiers have antibacterial effects, or certain components can selectively interact with preservatives physicochemically, which will affect the effectiveness of the use of preservatives to varying degrees.

Food ingredients that have a general effect on food additive preservatives are salt, carbohydrates and alcohol, all of which reduce the activity of enzymes in microorganisms, both of which also contribute to preservatives, however salt can also change the distribution coefficient of preservatives and make them unevenly distributed. Thus, it may adversely affect the preservative effect. Sugar in carbohydrates, itself a nutrient source for microorganisms, can promote the growth of microorganisms when the concentration is suitable, but the effect of sugar on the distribution coefficient is generally lower than that of salt, alcohol is a bactericidal agent at higher concentrations and has an inhibitory effect at lower concentrations, and generally alcohol can enhance the effect of preservatives.

Pay special attention to the ingredients in the food and the preservative chemical reaction, which may make the preservative partially or completely invalid, or produce side effects, for example, SO2 and sulfites react with aldehydes, ketones and sugars in the food, and nitrite may generate more toxic nitrosamines. Therefore, the use of preservatives should first consult the relevant information.

Preservatives will also be decomposed by microorganisms in food, especially organic preservatives, it may even become a carbon source for microorganisms, such as sorbic acid can be reduced to sorbitol by lactic acid bacteria, so improper use, preservatives are not only ineffective, but also may be used by microorganisms.

In conclusion, the food additives and ingredients research group of East China University of Science and Technology believes that once the microorganisms in the food start to act, even if the preservatives are added to stop the spoilage, it is impossible to restore the food to the sensory freshness. Therefore, no matter how effective the preservative is, it must make sure that the food is under a very good hygienic condition as soon as it starts processing, which is also one of the principles of preservative use.