Question

Lactometer reading test is used to test milk for detection of adulteration of -

• A. Odour
• B. Appearence
• C. Water
• D. Temperature

Hint:

Remember the simple principle: {Lacto} (milk) + {meter} (measure). It measures milk's density. Since water is the most common, cheapest, and least dense adulterant, the lactometer is the go-to tool to detect it. A low reading means added water.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question asks about the primary purpose of using a lactometer in milk testing. A lactometer is a type of hydrometer, an instrument used for measuring the specific gravity (or density) of liquids.
Step 2: Detailed Explanation:
The specific gravity of normal milk is consistent, typically ranging from 1.028 to 1.032. This density is a result of its components: milk solids (fat, protein, lactose, minerals), which are denser than water, and the water itself.
Adulteration with Water: Water has a specific gravity of 1.000. When water is added to milk, it dilutes the milk solids, causing the overall specific gravity of the mixture to decrease. A lactometer can easily detect this drop in specific gravity, indicating the addition of water.
Other options: A lactometer does not measure odour, appearance (visual attributes), or temperature. While the reading must be corrected for temperature, the instrument itself does not measure temperature.
Step 3: Final Answer:
The lactometer reading is primarily used to detect the adulteration of milk with added water.