Question

The Gerber method is used to determine:

• A. Milk protein
• B. Milk fat
• C. Milk lactose
• D. Milk minerals

Hint:

The Gerber method measures the fat content volumetrically. It is highly popular in dairy laboratories alongside the Babcock method.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to identify the nutritional constituent of milk determined by the Gerber method.

Step 2: Key Formula or Approach:
The Gerber method is a volumetric analytical method in which concentrated sulfuric acid digests proteins, allowing the fat to separate and be measured in a specialized graduated glass tube called a butyrometer.

Step 3: Detailed Explanation:

• Concentrated sulfuric acid ($\text{H}_2\text{SO}_4$, around 90-91% concentration) is mixed with milk inside a butyrometer. The acid digests and hydrolyzes casein and other milk proteins, generating heat that melts fat globules.

• Amyl alcohol is added to facilitate a distinct phase separation between the fat column and the aqueous phase.

• The mixture is centrifuged, allowing the liquid milk fat to rise into the graduated neck of the butyrometer, where the percentage is read directly.

• Other components like protein (Kjeldahl method), lactose (polarimetry), and minerals (dry ashing) require different analytical techniques.

Step 4: Final Answer:
Therefore, the Gerber method is specifically used to determine milk fat.