Question

One of the natural inhibitory system in bovine milk consists of -

• A. Lactoperoxidase, lysozyme and hydrogen peroxide
• B. Lactoperoxidase, thiocyanate and ozone
• C. Lactoperoxidase, thiocyanate and hydrogen peroxide
• D. Lactoperoxidase, hydrogen peroxide and ozone

Hint:

The FAO/WHO recommends the artificial activation of the natural Lactoperoxidase system (by adding safe levels of sodium thiocyanate and sodium percarbonate) to preserve raw milk in warm tropical regions where mechanical refrigeration is unavailable.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Bovine milk contains several natural antimicrobial enzymes and proteins that protect the newborn calf and inhibit bacterial spoilage during the initial post-milking phase.

Step 2: Detailed Explanation:
The Lactoperoxidase System (LP-system) is the most prominent natural, non-immunological antimicrobial defense system in bovine milk.
It consists of three essential, interacting components:
1. Lactoperoxidase (LP): An enzyme naturally synthesized by the mammary gland and present in high concentrations in milk.
2. Thiocyanate (\(\text{SCN}^-\)): A naturally occurring ion in milk derived from the animal's green feed.
3. Hydrogen Peroxide (\(\text{H}_2\text{O}_2\)): Formed by polymorphonuclear leukocytes or produced by lactic acid bacteria under aerobic conditions.
Lactoperoxidase catalyzes the oxidation of thiocyanate by hydrogen peroxide into short-lived, highly bactericidal intermediate compounds like hypothiocyanite (\(\text{OSCN}^-\)).
These intermediates destroy bacterial cell membranes and oxidize sulfhydryl groups of bacterial metabolic enzymes.

Step 3: Final Answer:
The natural inhibitory system consists of Lactoperoxidase, thiocyanate, and hydrogen peroxide, which corresponds to option (C).