Definite volume refers to something which has a consistent, unchanging volume, which in practical terms may mean a static mass and density, or a predetermined shape, either of which will dictate volume. A cube with side length l has a definite volume because it can only be exactly one size.
One cup of raw plantains or one medium sized raw plantain contains: ~180-200 calories, 0.5 g total fat, 47-50 g carbohydrates, 3.5 g dietary fiber, 22 g sugar and 2 g protein. Because of it's high carbohydrate content, you need to monitor your portion, otherwise your blood sugars will spike.
Pineapple also contains some fiber. A single cup (165 grams) of pineapple contains 21.7 grams of carbohydrates and 2.3 grams of fiber, meaning that 19.4 grams of digestible carbs are present in each cup. The glycemic index value (GI) of pineapple can range from 45 to 66, which is in the medium range (4).