LPT 311: Milk and Milk Products Technology (1+1)

ESTIMATION OF ACIDITY IN CREAM

• When the cream is intended for long storage the acidity should be reduced (before churning) to 0.06 to 0.08 percent as lactic acid, and for early consumption a level of 0.25 to 0.35 percent lactic acid is preferred. Acidity if excess, should be neutralised before churning.
• Calcium hydroxide can be added at a level of 490 g or sodium bicarbonate can be added at a level of 830 g of per Kg lactic acid.

Procedure

• Heat the cream to boiling point for one minute before testing for acidity. Take 10 ml of cream in porcelain dish to which a few drops of phenopthalin indicator is added. It is then titrated against N/10 NaOH taken in a burette.

Calculation

Titratable acidity = 9 V₁N₁ / V₂

Where,

V₁: Titre value

N₁: Normality of NaOH

V₂: Volume of cream

Result 

• The acidity of the given sample of cream is = -------------