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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Teaser fruit bite!

Here is a teaser question for you.
Name 5 fruits that are native to the region you live. Note that these fruits must have historically evolved in your region in order to be counted. Also, it would be nice to include the scientific name along with your list (use http://www.google.com/). Here is mine:

List of fruits native to southern India
1) Mango (http://en.wikipedia.org/wiki/Mangifera_indica)
2) Jack fruit  (http://en.wikipedia.org/wiki/Artocarpus_heterophyllus)
3) Lemon (http://en.wikipedia.org/wiki/Citrus_limon)
4) Jambul (http://en.wikipedia.org/wiki/Syzygium_cumini)
5) Jujube (http://en.wikipedia.org/wiki/Ziziphus_zizyphus) 

Nature research?

I consider myself as a nature researcher. However, my definition of nature includes human beings as well.

Surprise surprise!

It’s funny when I ask people about nature, the first things that come to their minds are the native virgin forests of Amazon, wilderness in Alaska, or the great savannas of Africa. I can personally guarantee that none of these pictures include any trace of humans. Well credit is due to all nature documentary film makers who have done such a wonderful job of keeping humans out of nature. We have bought that argument so bad that we have coined some pretty nonsensical terms such as 'human versus nature'.

Anyways, humans are very much a part of nature and have been so for the past 200,000 years in the 4,550,000,000 years of earth's history (http://en.wikipedia.org/wiki/History_of_the_Earth). This is equivalent to 1 part in 22,750. What does this number mean? This is approximately equivalent to 1 day in the life of a human being living for 62 years (http://en.wikipedia.org/wiki/Life_expectancy). To put it in visual context that my grandfather can understand (he was a rice farmer!), this is equivalent to taking one grain in 568 grams (about 1 pound) of rice assuming the average mass of 1 grain of rice is 25 milligrams. Here is an interesting story of rice counting for the mathematically challenged http://en.wikipedia.org/wiki/Wheat_and_chessboard_problem .

For those in the academic and scientific circle, I am a researcher in the field of sustainable development of human dominated ecosystems.