Artificial fruit ripening

Fruit ripening can be induced by a chemical called calcium carbide (CaC2). When calcium carbide reacts with water it produces ethylene (C2H4)gas. Ethylene is also called acetylene. There is nothing fancy about this ethylene gas, in fact all of us have handled ethylene in our lives in the form of polymer called polyethylene famously known as polythene. Yes its that plastic stuff! And a polymer is nothing but a long chain of ethylene molecules joined head to toe.

Now ethylene as a gas is not toxic to humans. It is dangerous as an asphyxiant (fancy name for suffocation by lack of oxygen). However, ethylene is also a plant hormone. It is responsible for leaf senescence (falling of leaves), flowering, ripening of fruit among other things. So when we use moist CaC2 on mangoes, we are actually producing ethylene and artificially providing hormones to hasten the ripening process. This can cause a rapid ripening which is quite different from the natural slow ripening and this results in poor taste of the fruit. It must be noted that most of the fruits sold worldwide uses this technique of using the ethylene hormone for fruit ripening, although not necessarily using CaC2. Also it must be noted that this form of ripening greatly reduces shelf life of the fruit.

Now, I am unable to find conclusive evidence indicating that ethylene induced ripening is harmful for humans. It sure does taste different and not as pleasant as the naturally ripened fruit, but there is insufficient literature on the harmful effects of ethylene. There are powerful commercial interests behind this process and it might take a while before we can get sufficient information regarding this.

However, what we can say conclusively is that using CaC2 to produce ethylene is harmful. The harm is not caused by ethylene, but the other substances present in the rock form of CaC2 that are not intended to be there. These are some heavy metals such as arsenic, mercury etc. It is these substances that actually do the harm because they leach into the fruit and can cause several disorders including cancer and nervous malfunction. This part of the using CaC2 is conclusively established as harmful to human consumption.

In summary, although it has not been established that ethylene induced ripening is harmful to humans, using CaC2 for ripening is harmful due to the presence of trace heavy metals such as arsenic and mercury. Moreover, these artificially ripened fruits do not taste good either. Hence in conclusion it is wise to stay away from artificially ripened fruits both for the taste and for the proven or yet unproven harmful health effects.

Useful links:

1. http://en.wikipedia.org/wiki/Ripening
2. http://en.wikipedia.org/wiki/Ethylene
3. http://en.wikipedia.org/wiki/Calcium_carbide
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