Question

Cotton fibre is made up of:

• A. Crude fibre
• B. Starch
• C. Cellulose
• D. Lignin

Hint:

Because cotton lint is nearly pure cellulose, it is used as a standard reference material for studying cellulose chemistry and fiber technology.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Cotton is a premier natural fiber crop grown globally.
The commercial fiber (lint) consists of unicellular hairs that develop from the outer epidermis of the cottonseed coat.

Step 2: Detailed Explanation:
The biochemical composition of a mature cotton fiber is almost pure cellulose.
A raw, unprocessed cotton fiber consists of:
- Cellulose: \( 90\% \text{ to } 95\% \)
- Water: \( 6\% \text{ to } 8\% \)
- Waxes, pectins, and proteins: \( 1\% \text{ to } 2\% \)
Once the raw fiber is scoured and bleached, the cellulose content exceeds \( 99\% \).
Cellulose is a linear, long-chain polymer of glucose units linked by \(\beta\)-1,4-glycosidic bonds.
This crystalline structure gives the cotton fiber its high tensile strength, durability, and water-absorption capacity.
Starch is a storage polysaccharide and is not found in fibers.
Lignin is a complex polymer that provides woody rigidity to plant cell walls (found in jute and coir but absent in soft cotton lint).
Crude fiber is a nutritional term used to describe indigestible plant matter in animal feed.

Step 2: Final Answer:
Cotton fiber is made up of Cellulose.