Is the mucus normal white and clear or off white/yellowish and turbid. If its turbid u may need antibiotics otherwise nothing to be worried about.

The sinuses, throat, and nose all produce mucus that a person usually swallows unconsciously. When mucus starts to build up or trickle down the back of the throat, this is known as postnasal drip. Causes of postnasal drip include infections, allergies, and acid reflux. So if you are facing mucus on particular food, may be you are allergic to that food or it's the normal mucous production.