Whey or buttermilk is the liquid obtained after coagulate the milk in cheese production, once it is separated from the cheese curd (casein and fat). Per one kilo of cheese 9 litres of whey are produced. Thus, whey represents about 90% of milk volume and contains more than half of its nutrients.
Milk is one the richest foods that exists thanks to its high nutritional value. It is mainly comprised of water, fat, proteins, carbohydrates (lactose), calcium, minerals and salt. It contains 87% of water, which makes a heterogeneous and very complex blend where minerals and carbohydrates are dissolved, proteins are in suspension form and fats are in small particles insoluble in water.
While representing around 90% of milk, whey contains most part of its water-soluble compounds, 95% lactose (milk sugar), 25% proteins and 8% fatty matter. Although its composition varies depending on the origin of the milk and the type of the processed cheese, in general the approximate content is 93.1% water, 4.9% lactose, 0.9% raw protein, 0.6% minerals, 0.3% fat, 0.2% lactic acid and water-soluble vitamins. About 70% of raw protein found in the whey corresponds to proteins with a nutritional value greater than the casein one.
