Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
We are not aware of the names of preservatives that are added to the factorization of some foods. In order to find out about this matter, you can refer to the people who are running the production factory of this type of food in the country where you live.
If these materials are added as they are, and they are extracted from Haram things, like pork, or dead animals, then it is Haram to consume food containing these materials, even if it is only a small quantity that is added.
However, if these materials (preservatives) are treated before they are added until they are transformed from one state to another state which is not Haram, then in this case, it would be permissible to consume food containing these materials.
Allah knows best.