Recently we received the following questions:
> Questions: It is my understanding that a mould, common in the
> common, commercial banana, has carcinogenic properties. I am under
> the impression that the blackening of the banana flesh may, usually,
> be attributed to the mould, and not merely oxidization.
> I presume the carcinogenic chemicals would be secreted by the
> mycelium of the mould.
> I also presume, as found in the secretions of other fungi, that the
> chemicals are hardy and not easily degraded by cooking.
> If correct, then the common practice, of using discoloured bananas in
> cooking, may tend to be somewhat dangerous and should be discouraged.
> Have you information to support my assumptions, or can you refer me
> to other resources.
Answer: It is true that the sunken black/brown spots on the banana fruit are due to a mould. The condition is referred to as anthracnose. The mould that causes the spots is called Colletotrichum musae. It is a post-harvest problem of banana fruits all over the world. Unless the banana is almost rotten the mould is usually restricted to the banana peel. The pulp is not affected. Anthracnose develops when dormant infections of Colletotrichum musae in the green peel resume growth as the fruits ripen.
Colletotrichum musae is not known to be carcinogenic. I have not seen any documentation of poisoning of humans or animals after eating bananas with anthracnose.
Do you have a mould problem? Call us at (905)290-9101