Why do players consume bananas and not other fruits during tennis matches?

Why do players consume bananas and not other fruits during tennis matches?

Image Source: en.wikipedia.org

Athletic and sport activities like tennis demand lot of energy. While there are many sugar containing energy sources such as fruits or raw glucose itself, a good energy source will need to provide sustained energy as well as other benefits. Banana is the most preferred energy source of athletes.It contains different types of sugars and is also a very good source of Potassium. Tennis players also get dehydrated a lot and lose salts in the body. The sodium-potassium balance in the body is very important to maintain constant blood supply, which in turn determines energy supply to active parts of the body. Banana provides enough potassium, and sustained energy from various sugars. Banana is also available all over the world almost all times of the year. Last, but not least, unlike many other fruits, bananas come in their own hygienic natural `packing', which can just be peeled off and eaten safely.

Source: thehindu.com

Why Do Brinjals And Apples Become Dark When They Are Kept Open After Cutting?

Why Do Brinjals And Apples Become Dark When They Are Kept Open After Cutting?

The reason for the darkening of the fruits, when kept open after cutting can be related to the mechanism of ripening. Hence, it is essential to know about the ripening mechanism at first and then extend it to explain the reason, for the question asked.

In many fruits, especially the fleshy types, there are marked changes in their `respiration rate' after they mature. In certain fruits, there is a considerable increase in the respiration rate at the time of `ripening', which is known as climacteric rise.

Even after the fruits are harvested, they continue to respire, which leads to consumption of food, water and other cellular fluids. This results in the breakdown of tissues eventually and causes the perishability of fruits.

The onset of fruit ripening happens due to the release of ethylene (H{-2}C=CH{-2}). Earlier it was mentioned that there is climacteric respiratory rise during ripening. In other words, the climacteric respiration rise and release of C{-2}H{-4} complement each other in facilitating the ripening.

As a consequence of this, metabolic and physical transformations happen such as:

-Hydrolysis of starch to sugar.

-`Softening' (i.e.) increase in the permeability of the cell walls.

- Changes in the `pigmentaiton' and `flavor' and

eventually resulting in overall breakdown of tissues.

Hence, if the climacteric rise is appropriately controlled, then one can regulate the C{-2}H{-4} release, which might help in controlling the rate of ripening.

When a fruit is cut and kept open, then there is greater availability of Oxygen (O{-2}). So, there is an increase in the respiration rate (and concomitant increase in the release of C{-2}H{-4}), resulting in the above-mentioned metabolic transformations more readily (i.e.) faster breakdown of tissues.

Thus, the darkening is nothing but ``over-ripening''. In a sense, the fruit ripening may be regarded as a special case of senescence.

The respiration rate is calculated by experimentally measuring CO{-2} liberated{rcub}

Note: Apple, banana exhibit climacteric behaviour, while citrus fruits like lemon, orange do no exhibit this behaviour.

Published in The Hindu on Dec 13, 2001.