The inner core is fluff and the outer core is masquerade, but this rubbish does not apply to plant kingdom. The inner core in plant stems and tree trunks are important since through the inner core the plant absorbs water and nutrients and sometimes serves as vegetable for good eating.
The most interesting part of Banana or Plantain plant is the tender inner core of the trunk of the plant. Once the ripened fruit bunch was trimmed from the tree, the trunk is chopped off at the ground level; The trunk is then sliced lengthwise to remove layers of thick skin that separates easily to expose a long, cylindrical, white, shiny, tender looking inner core called 'Davva' in a local language in South India. The inner core is cut into 2 or 3 feet long pieces to be sold in local markets as a vegetable. The inner core is mostly water as in water chestnut with no taste. To inner core is laced with long thin tough fibers to keep it firm and straight; these need to be removed carefully while chopping into small pieces before cooking. Various ingredients that include ground mixture of sesame seed, mustard seed and other spices bring an interesting taste to the tasteless inner core of the trunk. The only health benefit from eating this vegetable is it provides lots of fiber to the diet but again the cooking is tedious and time taking, only patience is the largest ingredient in its cooking. In most Banana growing countries, after the fruit bunch was cut-off, the trunk is discarded along with inner core; only in very few cultures in South Asia, the usefulness of Banana plant trunk inner core was realized for its vegetable value.