Manufacturers can choose to quote either the E number of the additive or its chemical name or both in the ingredients list. This can be confusing for shoppers. With more and more people wanting to avoid foods with unnecessary additives, some manufacturers obviously hope that by leaving off an 'E' number we'll think the food is more ‘natural’.
As a rule of thumb, if the ingredients list contains a long list of unfamiliar-sounding chemical names for ingredients that you wouldn’t add to your own cooking, then you can be pretty sure it contains several additives. A long list of additives usually means the food is highly processed and has fewer ‘real’ ingredients.