Prunes are just plums that are dried either naturally in the sun or through dehydration. Prunes are black in colour and have a wrinkled outer appearance. The high fiber content of dry prunes can sometimes make them tough to eat, in which case you can soak them overnight and eat them the next morning. If you do this, don t throw the water you used to soak the prune away it now contains beneficial nutrients, too! Add it to your fruit juice or smoothie, or drink it as is to acquire its benefits. Every 100 g of prunes contains 9 percent of the daily recommended iron intake.