Substances that are added to food to maintain or improve the safety, freshness, taste, texture, or appearance of food are known as food additives. They include antioxidants, preservatives, color agents, flavoring agents, anti-infective agents, etc. The use of food additives is only justified when their use has a technological need, does not mislead consumers, and serves a well-defined technological function, such as to preserve the nutritional quality of the food or enhance the stability of the food.
The starting point for determining whether a food additive can be used without having harmful effects is to establish the acceptable daily intake (ADI). The ADI is an estimate of the amount of an additive in food or drinking water that can be safely consumed daily over a lifetime without adverse health effects.