Most varieties of bananas sold in the United States contain no seeds within the fruit. Wild banana varieties found in Africa and Asia have dark, hard-angled or rounded seeds embedded into the fruit's flesh. These seeds are harvested to replant and to press them for their oil. Extracting the seeds from these wild bananas is a messy yet simple operation.
Select a wild banana that gives to slight pressure so you know it is fully ripened and the seeds have matured. Ask your grocer about special-ordering these rare bananas or collect them on a trip to Africa or Asia. Check with customs before transporting any whole produce out of the country; they may insist you only take seeds.
Use a sharp knife to make a shallow incision into the peel of the banana. Try not to actually cut into the flesh, just break the peel for easy opening.
Spread your newly opened slit and remove all the flesh and seeds contained inside. You may want to wear a pair of food-safe plastic gloves to keep the sticky fruit sugars off of your hands.
Squeeze the flesh of the banana with one hand as you pluck out the exposed seeds with the other. Seeds will be oblong and hard and appear dark brown or black with varying size and shape.
Rinse your harvested seeds in warm running water to remove any remaining banana flesh, then place them into a small collection bowl lined with a paper towel to air dry.