Question

It is a chemical used to test the presence of metanil yellow colour in turmeric.

• A. Concentrated hydrochloric acid
• B. Iodine
• C. Copper acetate
• D. Sucrose solution

Hint:

A simple food adulteration test: adding concentrated HCl to turmeric will turn the mixture pink if the harmful dye metanil yellow is present.

Answer 1

The Correct Option is A

Step 1: Understanding food adulteration in turmeric.
Turmeric is a commonly used spice in cooking and food preparation. Sometimes it is adulterated with a synthetic dye called Metanil Yellow to enhance its bright yellow colour. Metanil yellow is a non-permitted artificial dye and is harmful to health. Therefore, chemical tests are used to detect its presence in turmeric powder.
Step 2: Chemical test for metanil yellow.
To detect the presence of metanil yellow in turmeric, a small quantity of turmeric powder is mixed with concentrated hydrochloric acid (HCl). If metanil yellow is present, the colour of the mixture changes to pink or magenta. This colour change confirms adulteration in turmeric.
Step 3: Comparison with other options.

• (A) Concentrated hydrochloric acid: Correct. It is used as a chemical reagent to test the presence of metanil yellow in turmeric by producing a pink colour.
• (B) Iodine: Incorrect. Iodine solution is commonly used to test the presence of starch, not metanil yellow.
• (C) Copper acetate: Incorrect. Copper acetate is not used for testing metanil yellow adulteration in turmeric.
• (D) Sucrose solution: Incorrect. Sucrose solution is simply a sugar solution and has no role in detecting food adulteration in turmeric.

Step 4: Conclusion.
Thus, concentrated hydrochloric acid is the chemical used to test the presence of metanil yellow colour in turmeric. Final Answer: Concentrated hydrochloric acid.