Fruits and Leaves

Fruits and leaves of a plant are part of our 'Daily life'. Then, why some fruits are sweet and others are sour?
Some fruits like apple, grape, watermelon, chickoo and mango are sweet where as fruits like lemon, raw mango, certain grapes and gooseberry (Amla) are sour in taste. Each fruit will have a distinct taste which will be different from the taste of any other fruit. We can identify a fruit from its taste. The distinct taste of certain fruit depends on what substances it contains.
Usually a fruit contains acids, vitamins, proteins, starch and some sugar and cellulose mixing with each other. The taste of any fruit depends on the way how exactly these substances are mixed in it. If a fruit contains more percentage of sugar, it tastes sweet. As lemon contains more acids it tastes sour. An orange tastes sweet and sour as it is abundant in both sugar and acids.

Most of the fruits are abundant in acids when they are in raw condition. As they ripen the amount of acids in them decreases and sugar content increases infact, even a mango or a grape will be sour when they are raw. A banana which is tasteless because of more starch in it. When it is raw, tastes sweet and delicious. When it ripens because, the starch is converted into sugar. Inspite of all these reasons why some fruits are sweet and others are sour, we cannot explain why a lemon is rich in acids while a ripe mango is rich in sugar.

Two oranges and two mangoes need not be same in taste. This is because the little difference in the composition of the substances in them. But a mango will have a distinct taste when compared to an orange.

Why tender leaves of a plant are 'pink' in colour and later turn 'green' ?
We observe that the leaves of plants like rose, neem and mango in their earlier stages will be pink in colour and later turn into green.

leaves consist different substances and each substance has its characteristic colour. For example, the substance 'chlorophyll' in a leaf is green in colour where as 'carotene' is yellow. If different coloured substances are present in a leaf, it exhibits the colour of that mixture. Most of the leaves consists chlorophyll and carotene and they appear green.

Tender or newly grown leaves contain a reddish substance called 'anthocyanin'. Because of this substance is abundant in those leaves they appear pink or red. As the plant grow, chlorophyll and carotene are poduced in the leaves, they turn green.

Lakshmi Emani

Published date : 06 Jul 2012 01:41PM