In most cases it is seen as not appropriate when you talk with your mouth full. From a presentation point of view it is also not the right thing to do. Do not have food in your mouth while presenting.
You will not sound at your best when you talk with your mouth full. It is more difficult to articulate while speaking and eating. Chances are that part of your audience does not understand what you are saying and will get distracted.
You also risk “speaking with consumption” and spit out food while talking. There do not eat while presenting. Note that the same applies for chewing gum. No chewing gum while presenting.