Sediment Tests

 

Milk can be scored for sediment either by observing the particles of sediment which may have settled at the bottom of the bottle or by observing the sediment collected on a filter disc.

Objective:

·         To assess the cleanliness of milk received

Apparatus

·         Sediment tester

·         Sediment discs

·         Standard sediment discs

Procedure

A. Off-bottom sediment test

• Insert sediment pad in the space provided. Dip the tester in milk up to bottom without disturbing the milk.
• By pulling out the plunger collect milk slowly from different parts of the bottom. Later, press the plunger down.
• Remove the sediment pad and compare with the standard sediment disc pads provided or find out the weight of sediment and Compare the sediment disc with the prepared standard sediment discs and record the sediment score.

B. Mixed sample sediment test

• Insert sediment pad in the mixed sample sediment tester.
• Pass a known quantity of the milk (500 ml) through the pad.
• Remove the pad from tester.
• Compare the sediment pad with the standard pad provided or find out weight of sediment and grade the milk according to I.S.I. standards as given below: -

              Amount of sediment in disc (mg)            Quality of milk

0.0                                                                   Excellent

              0.2                                                                 Good

              0.5                                                                 Fair   

              1.0                                                                 Bad

              2.0                                                                 Very bad