A polysaccharide 'X' on boiling with dil H2SO4 at 393 K under 2-3 atm pressure yields 'Y'. 'Y' on treatment with bromine water gives gluconic acid. 'X' contains $\beta$-glycosidic linkages only. Compound 'X' is :

Question

A polysaccharide 'X' on boiling with dil H₂SO₄ at 393 K under 2-3 atm pressure yields 'Y'. 'Y' on treatment with bromine water gives gluconic acid. 'X' contains $\beta$-glycosidic linkages only. Compound 'X' is :

starch