proteins and polypeptides
Yes predominantly casein. If you ever see curdled milk, the chunks are the protein. There is a lot of protein. If you want to test this take some milk and pour something acidic into it. It will curdle. Sieve out the solid and see how much liquid is left. Milk contains about 3% protein.
All natural milk contains proteins.
Not all of it, milk contains sugars, proteins and fats.
Milk proteins are Whey and Casein.
Proteins from milk are precipitated.
proteins
animal proteins are called first class proteins.
Whey proteins are the milk proteins that are obtained by acidifying skim milk to pH 4.7 and removing the precipitated casein. Whey proteins are present for about 20% of total milk protein content.
Depending on the year, India or the USA. These are by far the biggest producers. The next group (France, Germany, Brazil, etc.) doesn't even have half their totals.
i think the solid waste which remains after the sieving of milk
milk proteins are used as ingredients in a wide range of food products both for their nutritional value and for their functionality.