Yikes! What do you do when you are giving a presentation and you either burp or get the hiccups in the middle of it. If you speak for a long time, such a thing can very easily happen to you as well.
My general advice is that if you burp, try not to get red faced r apologize profusely about it for a long time. Make it brief and quick; simply say, “Excuse me, sorry about that” and move on. If you avoid looking mortified at what has just happened, the audience will move on as well. What you do not want is for the most memorable part of the entire presentation to be your burp or hiccup. So it is not a problem doing it, but how your react to it and handle it.
Do not such a minor issue bother or preoccupy your thoughts but you can do some things to minimize the chances of such a thing happening such as avoid drinking carbonated drinks before your speech or presentation. But overall, maintain a neutral and dismissive attitude towards such an instance if it does happen and move on quickly and the audience will forget about it as soon as it had happened.