Milk Testing – Alcohol Test
Objective:
To detect abnormal milk such as colostrums or mastitis milk.
Relevant Information:
The alcohol test is used for rapid assessment of stability of milk for processing particularly for condensing and sterilization. The alcohol test is useful as an indication of the mineral balance of milk and not as an index of developed acidity. The test aids in detection abnormal milk such as colostrums, milk from animals in late lactation, milk from animals suffering from mastitis and milk in which mineral balance has been disturbed.
Precaution:
Avoid direct heating of milk,
Material Required:
i. Milk sample,
ii. 68% Ethyl alcohol by weight (Density 0.8675 g/mi. at 27 0 C).
Apparatus:
1. Test tube 15 x 1.9 cm preferably with graduation mark at 5 and 10 ml.
2. Measure of alcohol for 5 ml.
3. Test tube stand.
Procedure:
1. Take 5 ml. of milk in test tube.
2. Add equal quantity of 68% Ethyl alcohol.
3. Mix the contents of the test tube by inverting several times.
4. Examine the tube and note any coagulation.
If coagulation has occurred fine particles of curd will be visible on the inside surface, presence of flake or curd denotes positive alcohol test. Such samples are rejected.