Banana Peels — More Than Just Comic Relief

NPR recently blogged about a new use for banana peels discovered by Brazilian environmental chemist Gustavo Castro working at Sao Paulo University. Seems that Castro, who is also a banana lover, often heard that most of the banana’s nutrients and proteins reside in the peel. So he decided to investigate their chemical composition.

What he discovered was high levels of nitrogen, sulfur and organic compounds such as carboxylic acids, which he suspected might be useful as a water purifier since these acids can bind with positively charged metals that leach into rivers from industrial mining operations.

According to his paper published in the American Chemical Society’s Industrial and Engineering Chemistry Research, the chopped, dried banana peels performed as well or better than many other water filtering agents such as silica or carbon. What’s more, they could be used up to 11 times before losing effectiveness in removing contaminants. The peels are especially attractive to scientists because of their low cost as a waste product and because they don’t have to be chemically modified in order to work.