To add, there is also a concept of acidic & base foods. If one has too much of base foods, like one day old lentils, or gourds, one may feel like having sticky spit, or white crust of lips, or sore throat. The home remedy is to have a thick soup of dried ginger, onions & black pepper. This balances the body acid back to ph7 levels.
The whole idea of acidic/basic foods is not grounded on the scientific meaning of basic/acidic.
Food considered to be "acidic" often has no particularly low pH, and vice versa. And most of all: you can't influence your body's pH (i.e. blood) by eating something specific. You would be dead immediately if this was possible.
The pH of your stomach content might vary if you just ate, but your body will create the acid by itself. As soon as you see food.
There might be still something to whole acidic/basic idea, but it has nothing to do with pH ;)
