Do foods that expand during frying, like many deep-fried delicacies, carry the risk of hot oil infiltrating their inner spaces, possibly leading to mouth burns upon consumption?
Here is what I want to say:
In a properly cooked, deep fried item, the internal temperature cannot exceed the boiling point of water (100C or 212F), and we are often looking to cook to a lower temperature than that to avoid over cooking. That is because when you are deep frying, the moisture in the food turns to steam. Until you get rid of all the moisture you can't get the internal temperature above the boiling point.
How much oil a fried food absorbs depends on the type of food, any coatings or breadings, the temperature of the oil...there are several variables.
People vary in their sensitivity, but you can burn your mouth at about 60C/140F and higher. So there is a risk of burning your mouth whether it is from residual oil that was absorbed in the process or just being hot from cooking.