Milk protein casein
With a contribution of about 80% to the total milk
protein, casein is the main protein of fresh milk and
can therefore easily be seen with acid precipitation.
Fresh milk has a pH of about 6.6. Lactobacilli metabolize
lactose into lactic acid and lower the pH value towards
the isoelectric point of caseinate (pH 6). Thereby casein
is denaturizing and precipitation occurs.
Metrohm's titrators in conjunction
with the Porotrode pH electrode offer
a fast and easy way to determine the titrable acidity
in protein rich samples as cheese, yoghurt, cream and
milk. Titration can also be used to determine the amount
of calcium and chloride present in milk, cheese and
butter.
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Food
Analysis 
