A fruit is the fleshy and sweet part of a tree or any flowering plant that contains seeds. Some fruits are poisonous while some are edible. Plants usually disseminate seeds using fruits. There are different types of fruits and each has its distinctive taste. Some fruits are sweet; some are sour, while others have no specific taste. For instance, watermelon, mangoes, grapes, guavas, and pawpaws are sweet while oranges and lemons are sour (Kalz, 2010).
The sweetness or sourness of fruit usually depends on the types of compounds that it contains. Fruits generally contain starch, cellulose, vitamins, certain acids, proteins, and fructose. All these compounds are in different proportions in a variety of fruits. Fruits that have more fructose usually taste sweeter while those with more acids are sour (Kalz, 2010). The orange fruit contains almost equal amounts of acids and fructose which makes it both sour and sweet. Usually, raw fruits do have more acids which make them sour but as they ripen, the amount of acid in them reduces and the quantity of sugar increases making them sweeter (Kalz, 2010). That is the reason why raw pawpaws are sour but become sweet when they ripen. Raw bananas on the other hand contain a lot of starch but as they ripen the starch is usually changed into fructose. The chemical changes normally occur inside the fruits as they ripen. Due to the chemical changes, the quantity of sugar rises in the fruits giving them a sweet taste. At some point, however, there may be dissimilarity of taste even in the same kinds of fruits. For example, two pawpaws or two apples might not taste the same. The reason why the same fruits might not taste the same is manifold: they may be of different varieties and may be due to variations in climate, growing technique, water, quality of soil, and manure. The variations change the compound proportions in the fruits making them have different tastes. Fruits such as lemons have an excessive quantity of acids which do not allow them to get sweet even after ripening. They are always sour (Marshall Cavendish Corporation, 2011).
The fruit ripening process is majorly responsible for the dispersal of seeds. Fruits that are normally dispersed by animals usually ripen in a way that appeals and attract the animals. Animal-dispersed seeds possess enzymes that give the fruits bright attractive colors and nice scents that normally increase their chances of being seen and eaten. On the other hand, fruits that disperse their seeds through wind-dispersal or self-dispersal are normally dehydrated after ripening such that they can burst open and expose the seeds to the wind for them to be spread (Beal, 2011).
The human consumption of fruits and grains normally affects the process of seed dispersal. Human beings disperse seeds in various ways. However, when human beings consume grains or fruits before they have dispersed the seeds, they interfere with the complete development of seeds. They also interfere with the change of acids into starch that is normally used at the dominance stage. Similarly, human activities, for instance, the consumption of fruits and seeds, do interfere with the dispersal process, especially for self-dispersed or wind-dispersed seeds (Beal, 2011).
After the seeds have been dispersed, the young seeds go through a resting period whereby maturation and consequent germination take place. With the appropriate provision of materials and nutrients that are necessary for germination, the seed normally uses the stored starch to provide the energy for seed germination. Metabolism of the stored starch that takes place in the seed only occurs after the seed has been dispersed and at the time of germination. Fruits and seeds normally contain their separate places for food storage. As a result, seeds do not use fructose or starch stored inside fruits for metabolism. The seeds use the food that is stored in the endosperm (Beal, 2011).
References
Beal, J. (2011). Seed Dispersal. New York: BiblioBazaar Publishers.
Kalz, J. (2010). Fruits. North Mankato: Sart Apple Media.
Marshall Cavendish Corporation. (2011). Exploring life science. New York: Marshall Cavendish.