Question

The difference in fat content between the top and bottom layers, expressed as a percentage of the top layer, is referred to as:

• A. Homogenisation accuracy
• B. Homogenisation index
• C. Homogenisation factor
• D. Homogenisation stability

Hint:

The USPHS Homogenization Index measures physical stability after 48 hours of cold storage, with a value of less than 10% indicating proper homogenization.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Homogenization breaks down fat globules in milk to prevent creaming (fat separation) during storage.
The efficiency of this process is evaluated using standardized storage and testing protocols.

Step 2: Detailed Explanation:
The US Public Health Service (USPHS) defines a standard method to evaluate the physical stability of homogenized milk.
The test involves storing a quart of homogenized milk under quiescent conditions at 4--5$^{\circ}$C for 48 hours.
After storage, the fat content of the top 100 ml layer is determined, along with the fat content of the remaining thoroughly mixed bottom layer.
The Homogenization Index is calculated as:
\[ \text{Homogenization Index (\%)} = \frac{\text{Fat \% in Top Layer} - \text{Fat \% in Bottom Layer}}{\text{Fat \% in Top Layer}} \times 100 \] According to the USPHS standard, milk is considered properly homogenized if this index is less than 10%.
This indicates that the fat remains uniformly distributed and is resistant to creaming during storage.
Other terms listed (homogenization accuracy, factor, and stability) are descriptive terms but do not represent this specific regulatory index.

Step 3: Final Answer:
Therefore, this measurement is referred to as the homogenization index.