Question:
There was some small piece of food (bread) which stuck in my teeth. While in Salaat, by mistake, I ate it. Will my Salaat be annulled?
Answer:
If the food particle that was swallowed was equal in size to a lentil/chick-pea or larger than that, the Salaah will be invalid. However, if it was less than in size than that, the Salaah will be valid. [Re:- Behishti Zewar Pg.137].