Question

Protein hydrolysate
Casein hydrolysate with improved qualities can be manufactured by adding proteolytic enzyme in 10% casein solution at pH 6-7 for five hours at suitable temperature. Hydrolysis can be carried out by single or two stage process.
Given below are two statements based on the above. One is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): The two stage process is preferred to overcome the problem of bitter taste in casein hydrolysate.
Reason (R): The casein solution is first digested using exopeptidase enzyme having high peptidase activity followed by using endopeptidase enzyme to remove residual bitter peptides and free amino acids.
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

To digest proteins efficiently, always follow this order:
- Endopeptidases first (to cut internal bonds and create more chain ends).
- Exopeptidases second (to trim the terminal ends and remove bitter peptides).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Enzymatic hydrolysis of proteins often produces hydrophobic peptides that have a bitter taste.
In casein hydrolysate production, a sequential two-stage enzymatic treatment is used to break down these bitter peptides.
Detailed Explanation:
Let us evaluate both statements:
- Assertion (A): During protein hydrolysis, endopeptidases cleave internal peptide bonds, which often exposes hydrophobic amino acids and produces bitter-tasting peptides.
Using a two-stage enzymatic hydrolysis process is the preferred method to break down these bitter compounds and improve the flavor of the final hydrolysate.
Therefore, Assertion (A) is true.
- Reason (R): The reason describes the sequence of the enzymes incorrectly:
1. In the first stage, an endopeptidase is used to break down the intact casein proteins into smaller peptide fragments.
2. In the second stage, an exopeptidase (such as an aminopeptidase or carboxypeptidase) is used. Exopeptidases cleave amino acids from the terminal ends of the peptides, releasing free amino acids and removing the bitter hydrophobic terminal residues.
The Reason statement reverses this sequence, claiming that exopeptidases are used first.
Therefore, Reason (R) is false.

Step 2: Final Answer:
The Assertion (A) is true, but the Reason (R) is false.