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5. (a) (i) List two qualitative tests and two quantitative tests normally carried out on milk - Leaving Cert Agricultural Science - Question 5 - 2017
Question 5
5. (a) (i) List two qualitative tests and two quantitative tests normally carried out on milk. (ii) Describe how you would carry out in the laboratory any one of th... show full transcript
Worked Solution & Example Answer:5. (a) (i) List two qualitative tests and two quantitative tests normally carried out on milk - Leaving Cert Agricultural Science - Question 5 - 2017
Step 1
Step 2
Describe how you would carry out in the laboratory any one of the quantitative tests referred to above.
Answer
Butterfat Test
To determine the butterfat content in milk, the Gerber method can be used, which is a widely accepted laboratory procedure.
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Preparation:
- Measure 10 cm³ of milk sample into a test tube.
- Add 10.75 cm³ of sulfuric acid to the test tube.
- Introduce 1 ml of ammonia alcohol (or stopper the test tube) and shake gently until the mixture becomes red.
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Centrifugation:
- Centrifuge the mixture at 1200 rpm for 4 minutes. This will separate the butterfat from the other components of milk.
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Reading Results:
- After centrifugation, read the fat layer on the calibrated scale of the test tube to determine the percentage of butterfat present in the milk sample.
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Record the Data:
- Document the percentage of butterfat and conclude based on standard criteria for milk quality.