DT Lab

DT Lab

EXPERIMENT - 01

Object
Identification of Dairy Tools.
Apparatus
Off the Bottom Milk Sediment Tester, Cream Sampler, Plunger, Milk Theif, Butter Traier, Scotch Hand, Ladle, Ice Cream Scoop, Butter Scoop, Centrifuge, Graduated Pipette, Double Bulb Acid Pipette, 10.75 ml Milk Pipette, 1 ml Emyl alcohol Pipette, Milk Butyrometer, Stopper, Key, 10 ml Automatic Tilt Measure, 1 ml Automatic Tilt Measure, Lactometer, Dairy Floating Thermometer, Deep Frying Thermometer, Separate Bowl Assembly, Cream Spout (Outlet), Skim Milk Spout.
(a) Off the Bottom Milk Sediment Tester: This dairy tool is used for detection of presence of sediments in milk.
(b) Cream  Sampler: Cream sampler is used for sampling of cream.
(c) Plunger: Plunger is used for proper mixing of milk on to the tank.
(d) Milk Theif: This dairy tool is used for taking a sample of butter.
(e) Scotch Hand: Scotch Hand is used for stering of milk (usually small quantity of milk) while heating.
(f) Ladle: Ladle is used for sterring the bulk quantity of milk while heating.
(g) Ice Cream Scoop: It is used for taking sample of ice cream.
(h) Butter Scoop: It is used for taking sample of butter.
(i) Centrifuge: This instrument is used for centrifugation of milk, to test milk fat.
(j) Graduated Pipette: It is used for taking out different kinds of reagents.
(k) Double Bulb Acid Pipette: It is used for taking out 10 ml of Sulpuric Acid during testing of fat content of milk.
(l) 10.75 ml Milk Pipette: It is used for taking out 10.75 ml of Sulphuric Acid during testing of fat content of milk.
(m) 1 ml Emyl Alcohol Pipette: It is used for taking out 1 ml of emyl alcohol for testing fat content of milk.
(n) Milk Butyrometer: It is the main equipment for determination of fat content in milk.
(o) Stopper: It is used for sealing of Butyrometer.
(p) Key: It is used for sealing of butyrometer with the help of stopper.
(q) 10 ml Automatic Tilt Measure: It is used for taking out 10 ml of Sulphuric Acid during testing  of fat content of milk. It is an alternative to Double Bulb Acid Pipette.
(r) 1 ml Automatic Tilt Measure: It is used for taking out 1 ml of emyl alcohol during testing of fat content of milk. It is an alternative to 1 ml emyl alcohol pipette.
(s) Lactometer: To determine specific gravity of milk.
(t) Dairy Floating Thermometer: It is a instrument used checking the temperature of milk.
(u) Deep Frying Thermometer: It is used for measurement of higer temperature of milk and milk products.
(v) Separate Bowl Assembly: It is heart of centrifugal cream separator mainly used for separation of cream and skim milk.
(w) Cream Spout (Outlet): It is a part of centrifugal cream separator. It is mainly an outlet for cream in centrifugal cream separator.
(x) Skim Milk Spout: It is a part of centrifugal cream separator. It is mainly an outlet for skim milk in centrifugal cream separator.

EXPERIMENT -02
Objective
Determination of percentage fat, percentage SNF, percentage total solids and specific gravity of given milk sample.
1. Determination of fat content in milk by Gerber Method.
Required Apparatus

• Milk Pipette
• 10 mlAutomatic Tilt Measure
• 1 ml Automatic Tilt Measure
• Stopper
• Key
• Centrifuge

Reagents Required

• Sulphuric Acid
• Amyl Alcohol

Procedure

1.  First of all, we will take a milk butyrometer.
2. By using  ml automatic tilt measure, we will take out 10 ml of Gerber sulphuric acid and transfer it into milk butyrometer.
3. By using 10.75 ml milk pipette, take out 10.75 ml milk and transfer it slowly into milk butyrometer.
4. By using 1 ml automatic tilt measure take out 1 ml of amyl alcohol and transfer it into butyrometer.
5. By using stopper and key seal the butyrometer.
6. Shake the butyrometer to insure uniform mixing of all three liquid (i.e., milk sample, Gerber sulphuric acid and amyl alcohol).
7. Open the lid of centrifuge and keep the butyrometer inside the centrifuge.
8. Tilt the centrifuge and rotate it about 1200-1300 rpm for 5 minutes.
9. After 5 minutes switch off the centrifuge and allow it to stop and open the lid and take out butyrometer
10. Observe the reading of butyrometer by using calibrated scale.

2. Determination od SNF, total solids and specific gravity of milk sample.

Required Apparatus

• Measuring Cylinder
• Lactometer
• Dairy Floating Thermometer

Procedure

1. First of all, fill the milk in measuring cylinder.
2. Allow the lactometer to flow in measuring cylinder.
3. Note down the reading of lactometer.
4. Calculate CLR

• CLR = LR + (difference in temperature of milk)0.1 + 0.5 i.e., CLR = LR (OT - ST)0.1 + 0.5.

where,

CLR - Corrected Lactometer Reading

LR - Lactometer Reading

OT - Observation Tempereature

ST - Standard Temperature (15.6 degree Celcius).

• Formula for SNF percentage:

% SNF = CLR/4 + 0.2 x fat % of milk + 0.5

where,

0.5 is miniscus corrected factor.

• Formula for Total Solid percentage:

% TS = CLR/4 + 1.2 x fat % of milk + 0.5

• Formula for specific gravity of milk:

Specific gravity of milk = 1 + CLR/1000.
Calculation [write it on the left hand side with pencil]

• Observed Temperature of Dairy Floating Thermometer, OT = 12 degree Celcius.
• Standard Temperature of Dairy Floating Thermometer, ST = 15.6 degree Celcius.
• Fat percentage = 3.7 %
• Lactometer Reading = 20

we know,

1. CLR = LR + (OT - ST)0.1 + 0.5

            = 20 + (12 - 15.6)0.1 + 0.5
            = 20 + (-3.6)0.1 + 0.5
            = 20.14
2. % SNF = 20.14/4 + (0.2)(3.7) + 0.5
                 = 5.035 + 0.74 + 0.5
                 = 6.275
3. % Total Solid = CLR/4 + (1.2)(fat % of milk) + 0.5
                             = 5.035 + 4.44 + 0.5
                             = 9.975
4. Specific Gravity of milk = 1 + CLR/1000
       = 1 + 20.14/1000
       = 1.02014
Result
Hence, the percentage fat, % SNF, % Total Solid and specific gravity of milk sample is 3.7%, 6.275%, 9.975% and 1.02014 respectively.
Conclusion
Hence, the specific gravity of milk is found to be low i.e., 1.02014 as compared to the normal milk/ pure milk. So, the milk sample for determination is impure.