Question

Bananas can be prevented from over ripening by

A. Maintaining them at room temperature

B. Refrigeration

C. Dipping in ascorbic solution

D. Storing in a freezer

Answer 1

Ripening of a fruit is a chemical change which cannot be reversed. During ripening, the pigments present in the skin of the fruit changes. Ripening of fruit is a hormonal change.

Complete Answer:

- Ripening of fruits is controlled by the ripening hormone. The ethylene gas produced by the plants stimulates fruit ripening.

- Ethylene coordinates the expression of genes which are responsible for rise in respiration, change in color, aroma and flavor. Acids present in the fruits are broken down during ripening which makes the fruit much sweeter.

- Ripening of bananas is controlled by ethylene. When the banana ripens, the change in color of the skin, softness and sugar content of the fruit take place. So over-ripening of bananas can be prevented by dipping in ascorbic acid solution.

- Storing the banana in a deep freezer can stop the activity of ethylene and prevent the fruit from ripening upto a limited extent. The freezing process reduces the rate of the degradation reactions and inhibits the microbiological and enzymatic activity and has only a slight effect on the initial vitamin C content of fruit.

- The Banana rots faster at room temperature. In the refrigerator, the skin of the banana turns black.

- Dipping in ascorbic acid adds vitamin c to the fruit which is lost during ripening.

Thus, the correct answer is C. Dipping in ascorbic solution.

Additional Information:

The artificial ripening of bananas can be done by ethylene gas, acetylene emitted from calcium carbide, ethylene glycol, alkyl alcohols.

Note: Banana is picked before ripening as it ripens and rots faster than any other fruit. The auxins inhibit the ripening. Iodine can be used as a ripening indicator as starch is converted to sugars during ripening.