Question

The ripening fruits soften due to

• A. Conversion of starch into sugars.
• B. Solubilisation of pectates in middle lamella.
• C. Formation of organic acids.
• D. Conversion of fats into carbohydrates.

Answer 1

Answer: (B)

Solubilisation of pectates in middle lamella.

The ripening of fruits mainly takes place under influence of a growth hormone known as ethylene. The fruits soften due to solubilisation of pectates in middle lamella. In fruit, the cell walls are mainly composed of polysaccharides including pectin. During ripening, a lot of the pectin is converted from a water insoluble form to a soluble one by certain degrading enzymes. These enzymes include polygalacturonase. This means that the fruit will become less firm as the structure of the fruit is degraded. Enzymatic breakdown and hydrolysis of storage polysaccharides occurs during ripening.The main storage polysaccharides include starch. These are broken down into shorter, water soluble molecules such as fructose, glucose and sucrose.

So, the correct answer is 'Solubilisation of pectates in middle lamella'