Question

Match List-I with List-II
List-I (Chemical compound):
(A) Hydrogen sulphide
(B) Glycollic acid ester of oleic acid
(C) 3-methyl butanol
(D) Trimethyl amine
List-II (Flavour Defect):
(I) tallowy
(II) malty
(III) fishy
(IV) cooked
Choose the correct answer from the options given below:

• (A) - (II), (B) - (III), (C) - (IV), (D) - (I)
• (A) - (IV), (B) - (I), (C) - (II), (D) - (III)
• (A) - (III), (B) - (I), (C) - (IV), (D) - (II)
• (A) - (IV), (B) - (III), (C) - (I), (D) - (II)

Hint:

To remember key flavor defects:
- Hydrogen sulphide is always linked to heat-induced "cooked" flavor.
- Trimethyl amine is a volatile compound universally associated with "fishy" odors in foods.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Flavour defects in milk and dairy products are caused by specific volatile chemical compounds.
These compounds arise from thermal processing, chemical oxidation, or microbial contamination.
Detailed Explanation:
Let us match each chemical compound with its associated flavour defect:
- (A) Hydrogen sulphide (\(H_2S\)): This volatile sulfur compound is released during high-temperature heat treatment of milk.
The denaturation of whey proteins, especially \(\beta\)-lactoglobulin, exposes sulfhydryl groups, generating a characteristic cooked or sulfhydryl flavor (IV).
- (B) Glycollic acid ester of oleic acid: This compound is associated with fat autoxidation.
The oxidative degradation of unsaturated fatty acids in lipids leads to the formation of compounds that produce a tallowy or cardboard-like oxidized flavor (I).
- (C) 3-methyl butanol: This volatile compound is produced by the growth of certain spoilage bacteria, particularly Lactococcus lactis subsp. maltigenes.
It imparts a distinct malty flavor defect (II) to milk and cream.
- (D) Trimethyl amine: This amine compound is formed through the hydrolysis and oxidation of lecithin in milk fat.
It is responsible for the highly objectionable fishy flavor defect (III).
Combining these matches:
\[ (A) \rightarrow (IV), \quad (B) \rightarrow (I), \quad (C) \rightarrow (II), \quad (D) \rightarrow (III) \] This matches option (B).

Step 2: Final Answer:
The correct match is (A) - (IV), (B) - (I), (C) - (II), (D) - (III).