Question

H2O2 (Hydrogen peroxide) is used as preservative in milk in the concentration of

• A. 300- 800 ppm
• B. 1000 - 1200 ppm
• C. More than 1200 ppm
• D. Less than 100 ppm

Hint:

Milk Preservation Additives: $\text{H}_2\text{O}_2$ direct preservation $\rightarrow 300-800\text{ ppm}$. Lactoperoxidase System (LPS) $\rightarrow 10-30\text{ ppm } \text{H}_2\text{O}_2 + 15\text{ ppm SCN}^-$.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Milk preservation chemistry: hydrogen peroxide acts as an antimicrobial oxidizing agent or activates the endogenous lactoperoxidase-thiocyanate system at controlled parts-per-million levels.
Key Formula or Approach:
\[ \text{Preservative Range of } \text{H}_2\text{O}_2 \text{ in Raw Milk} = 300 - 800\text{ ppm } (0.03\% - 0.08\% \text{ w/v}) \]

Step 2: Detailed Explanation:
In dairy technology and milk preservation:
- Hydrogen Peroxide ($\text{H}_2\text{O}_2$) is occasionally used to preserve raw milk in tropical areas where mechanical cooling infrastructure is lacking.
- When used as a direct chemical preservative (the LP-system requires only $10-30\text{ ppm}$), direct milk stabilization against spoilage bacteria without curdling or destroying vitamins is achieved at an effective concentration of 300 to 800 ppm ($0.03\%\text{ to } 0.08\%\text{ w/v}$).
- Excess $\text{H}_2\text{O}_2$ is decomposed prior to processing using the enzyme catalase.

Step 3: Final Answer:
Hence, H2O2 is used as a milk preservative in concentrations of 300- 800 ppm, matching option (A).