Okay, let me try to work through this question. The question is asking which statement about pasteurization of milk is NOT true. First, I need to remember what pasteurization involves. From what I recall, pasteurization is a process that heats milk to a specific temperature for a certain amount of time to kill pathogens and extend shelf life.

The correct answer is supposed to be the one that's false. Let's think about the different methods. There's the traditional method where milk is heated to around 63°C for 30 minutes, which is called low-temperature long-time (LTLT) pasteurization. Then there's the high-temperature short-time (HTST) method, which uses 72°C for 15 seconds. Both of these are standard pasteurization techniques.

Another method is ultra-pasteurization, which uses higher temps like 135°C for a few seconds. But I think ultra-pasteurization isn't considered standard pasteurization anymore. So any option that mentions ultra-pasteurization might be a distractor. Also, pasteurization doesn't sterilize the milk completely; it just reduces pathogens and some spoilage organisms. So if an option says it sterilizes, that's incorrect.

Now, let's consider the options. The question says "all except," so the false statement is the correct answer. Let's imagine the options:

A. Kills all microorganisms – probably false because pasteurization doesn't kill all microbes, just the harmful ones and some spoilage.

B. Preserves vitamin C – Hmm, pasteurization might reduce some heat-sensitive vitamins like C, so if an option says it preserves them, that's incorrect.

C. Done at 63°C for 30 minutes – That's correct for LTLT.

D. Increases shelf life – Yes, that's true.

So the false options would be A and B. If the correct answer is the one that's not true, then either A or B is the correct choice. Since the question asks for the "all except," the answer is the one that's incorrect. So if an option says pasteurization kills all microorganisms, that's wrong because it doesn't sterilize. Similarly, if it claims that vitamin C is preserved, that's also incorrect because pasteurization can reduce some vitamins. But the most common misconception is that pasteurization sterilizes milk, which it doesn't. So the correct answer is likely the option that states pasteurization kills all microorganisms.

**Core Concept**
Pasteurization is a heat treatment process designed to reduce pathogenic microorganisms in milk while preserving its nutritional quality. It does **not** achieve complete sterilization but eliminates most vegetative pathogens and spoilage organisms. Key parameters include time-temperature combinations like 63°C for 30 minutes (batch) or 72°C for 15 seconds (HTST).

**Why the Correct Answer is Right**
The false statement in the question is the one claiming pasteurization **sterilizes** milk. Pasteurization eliminates **vegetative pathogens** (e.g., *Salmonella*, *Mycobacterium tuberculosis*) and reduces spoilage bacteria but does **not kill heat-resistant spores** (e.g., *Clostridium botulinum*). Sterilization requires higher temperatures (e

✓ Correct Answer: C. Cause > 95% decrease in bacterial count