Question

Arrange the following biochemical reactions in ascending order of time taken during ripening of cheese
(A) Proteolysis
(B) Lactose fermentation
(C) Free fatty acid production
(D) Alcohol production

• A. (A), (B), (C), (D).
• B. (B), (C), (A), (D).
• C. (B), (A), (C), (D).
• D. (C), (B), (D), (A).

Hint:

Remember the metabolic sequence of cheese ripening:
Acid production from lactose occurs in hours, protein breakdown takes weeks to months, fat breakdown occurs over months, and volatile aroma development (including alcohols) requires long-term curing.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Cheese ripening is a complex biochemical process involving the enzymatic breakdown of the curd's primary components (lactose, proteins, and lipids).
These biochemical reactions occur at different rates and during different stages of the manufacturing and storage process.

Step 2: Detailed Explanation:
Let us analyze the time required for each biochemical reaction:
1. Lactose Fermentation (B): This is the earliest and fastest reaction in cheese making.
Lactic acid starter cultures ferment the lactose in milk into lactic acid within the first few hours of processing, pressing, and salting.
By the end of the first week of storage, almost all residual lactose is converted, making this the shortest reaction.
2. Proteolysis (A): This reaction begins early in the ripening process.
The hydrolysis of caseins into primary peptides is initiated by residual coagulant (chymosin) and plasmin within the first few weeks, and continues throughout the ripening period.
3. Free Fatty Acid Production (C): Lipolysis (fat breakdown) is generally a slower enzymatic process than proteolysis in most cheeses (excluding specialized blue or mold-ripened varieties).
Lipases slowly hydrolyze triglycerides into free fatty acids over several months, contributing to the development of the characteristic sharp flavor.
4. Alcohol Production (D): The generation of alcohols, esters, and complex volatile sulfur compounds via amino acid and fatty acid catabolism is a late-stage biochemical event.
These reactions require prolonged ripening, occurring towards the end of the curing cycle.

Step 3: Final Answer:
The ascending order of time taken for these biochemical reactions is: Lactose fermentation (B) \(\rightarrow\) Proteolysis (A) \(\rightarrow\) Free fatty acid production (C) \(\rightarrow\) Alcohol production (D).