The mango is a classic summer fruit, but for some it can bring out a rash when they handle or eat it. This irritation is not unique to mangos – in fact, there’s some surprising chemistry in common between mangos and poison ivy. In this post, we look at the chemical culprit, as well as some of the chemical compounds behind the flavour and aroma of mangoes.
We’ll start with the flavour and aroma of mangoes. Here there are a huge number of compounds which make varying contributions – over 270 volatile compounds have been detected in analysis, though not all of these make a significant contribution to taste and smell. Recent studies have identified esters as the main source of the mango’s fruity aroma, with one of the key contributors being ethyl butanoate.
A major contributor to the sweet note in the mango aroma is 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF for short). Interestingly this compound is also found in strawberries, and is also structurally similar to some of the compounds responsible for strawberry aroma.
There are plenty of other contributors too. Lactone compounds, such as γ-octalactone, can lend a coconut-like note to the aroma, and a whole host of terpenes are amongst the most abundant volatile compounds given off by mangoes – though they make a lesser contribution to their aroma.
So what about the rash some people experience when eating mangoes? Medically, it’s called contact dermatitis, and it’s caused by a particular set of compounds found in the skin of the mango. Mangoes are, as it happens, in the same plant family as poison ivy. Poison ivy can cause contact dermatitis due to the presence of urushiol, an oily substance found in the plant’s sap, and this same group of compounds are found (albeit usually at lower levels) in the skin of the mango.
Many people can eat mangoes with no problems, as sensitivity to urushiol is variable. Some people experience no reaction, while others can be very sensitive to it and react immediately. If you’re affected by it, there are a few things you can do. Firstly, it’s worth noting that urushiol is found at higher levels in green mangoes compared to ripe ones. Secondly, as it’s found in the peel, avoiding contact with the peel can help prevent any allergic reaction. Finally, antihistamines, if taken in advance, can help prevent the allergic response.
Enjoyed this post & graphic? Consider supporting Compound Interest on Patreon, and get previews of upcoming posts & more!
References & Further Reading
- Characterisation of major aroma-active compounds in mango (£) – J P Munafo and others
- Contribution of volatile compounds to mango aroma (£) – J A Pino and J Mesa