Whey protein determination in milk according to the Kjeldahl method

Milk proteins are the oldest and most widely consumed food proteins. There is currently a large interest in these substances, both in nutritional field and in technological application. The nitrogen compounds of milk can be divided in: casein proteins and non-casein nitrogen. Among this, there are soluble whey proteins. In order to determine soluble whey proteins, it’s necessary to know the amount of milk total nitrogen, non-casein nitrogen and non-proteins nitrogen substances.