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    Question

    The efficiency (adequacy) of pasteurization of milk is

    tested by
    A Phosphatase test Correct Answer Incorrect Answer
    B Ring test Correct Answer Incorrect Answer
    C Buffer test Correct Answer Incorrect Answer
    D None of the above Correct Answer Incorrect Answer

    Solution

    1. Science Behind the Test:  a. Alkaline phosphatase enzyme naturally present in raw milk  b. Destroyed at 72°C for 15 sec (HTST standards)  c. Residual enzyme indicates inadequate pasteurization 2. Testing Protocol:  a. Add disodium phenyl phosphate + buffer  b. Incubate at 37°C ± 1°C for 1 hour  c. Measure liberated phenol (colorimetric) 3. Regulatory Standards:  a. FSSAI: ≤ 350 mU/L for pasteurized milk  b. Codex Alimentarius: Complete inactivation required 4. Comparative Analysis:  5. Industry Practice:  a. Mandatory for all dairy processors  b. Automated test systems (e.g., MilkoScan FT3) widely adopted Technical Note: False positives may occur if milk is contaminated with microbial phosphatases. Confirmatory testing required per ISO 11816-1:2013.

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