Food additives are added for a variety of reasons. The following links list many types of additives.
11 Types of Food Additives – from Fooducate blog
Generally there are three main categories of additives:
1) Improve food’s appearance, taste, and texture.
This can include artificial colors, artificial flavors, artificial sweeteners, thickeners, anti-caking agents (prevents powders from clumping,) emulsifiers (prevents oil and water from separating), additives that add structure to food, and additives that prevent food from drying out.
The biggest flavor additives are sugar and salt. Processed foods (packaged foods produced in factories) tend to have a lot of added sugar and salt, including many foods where you wouldn’t expect those to be added. This is one of the big reasons why highly processed foods are generally much less healthy than less processed foods.
2) Preservatives
Antioxidants prevent foods from degrading. Some other additives slow the growth of bacteria and fungi.
3) Nutrients
Many foods are fortified with extra vitamins and minerals.