Amylose is a water-soluble part of starch. What is the percentage solubility of it?

15 to 20%

The correct answer is Option (2) → 15 to 20%

Starch is naturally composed of two distinct polysaccharide components: Amylose and Amylopectin. Amylose is the smaller, water-soluble fraction.

The correct percentage of starch that is made up of amylose is: 15 to 20%

Key Characteristics of Amylose

• Composition: It makes up approximately 15–20% of natural starch.
• Solubility: It is the water-soluble component of starch.
• Structure: It is a long, unbranched chain of $\alpha$-D-glucose units.
• Linkage: The glucose units are held together by C1–C4 glycosidic linkages.
• Shape: It typically forms a helical structure, which is responsible for the blue color produced during the iodine test.

Comparison with Amylopectin

By contrast, Amylopectin makes up the remaining 80–85% of starch. It is water-insoluble and has a branched structure involving both C1–C4 and C1–C6 glycosidic linkages.