Question

Which is not applicable for iodophores in dairy plant sanitation?

• A. Shows good activity aganist yeast and mold.
• B. More effective in alkaline pH
• C. Less effective at elevated temperature.
• D. Stable than chlorine in the presence of organic matter.

Hint:

Iodophors require an acidic pH (0 to 0) to release active germicidal iodine ($I_2$). At alkaline pH, the iodine is converted into inactive iodate, destroying its sanitizing power.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Iodophors are sanitizer complexes consisting of iodine bound to a non-ionic surfactant carrier, which slowly releases free diatomic iodine ($I_2$) as the active biocidal agent.
The chemical stability and germicidal activity of iodophors are highly dependent on the pH of the sanitizing solution.

Step 2: Detailed Explanation:
Iodophors are formulated to operate under acidic conditions (typically pH 0 to 0), where the active diatomic iodine species is stable and highly reactive.
In alkaline environments (high pH), the free iodine is rapidly converted into inactive, non-biocidal forms such as hypoiodite ($IO^-$) and iodate ($IO_3^-$), which severely reduces its sanitizing efficacy.
Additionally, iodophors are highly stable in the presence of organic matter and are less corrosive than chlorine-based sanitizers.
Therefore, the claim that iodophors are "More effective in alkaline pH" is false, making it the correct answer to the question.

Step 3: Final Answer
"More effective in alkaline pH" is not applicable to iodophors, as they lose their germicidal activity at high pH.