The correct option is (a).
Explanation
Qualitative analysis of food nutrients involves specific chemical tests that produce distinct colour changes to identify the presence of major biomolecules such as carbohydrates (starch), proteins, and fats.
Statement 1 is Correct:
The Iodine Test is the standard method for detecting starch. When a dilute iodine solution is added to a food sample containing starch, the iodine molecules get trapped in the helical structure of amylose (a component of starch), resulting in a blue-black colour.
Statement 2 is Incorrect:
The combination of Copper Sulphate ($CuSO_4$) and Caustic Soda (Sodium Hydroxide, $NaOH$) constitutes the reagents for the Biuret Test. This test is used to detect the presence of proteins (specifically peptide bonds), which turns the solution violet. It does not test for fats. The presence of fats is typically identified by the paper spot test, which leaves a translucent oily patch.
Key Takeaway:
Iodine solution indicates starch (blue-black colour), while Copper Sulphate and Caustic Soda (Biuret test) indicate proteins (violet colour).