Milk proteins can be of two types:

• cow's milk (the most common). EFSA expressed its opinion in 2012 (1)
• goat's milk (authorized by EFSA for infant feeding in 2004 - EFSA-Q-2003-019)

and are used in many sectors such as cosmetics, medicines, nutrition, bakery products.

Milk proteins are a category of macromolecules obtained from milk, which primarily includes casein and whey proteins.

Raw materials used in production. 

• The primary raw material is milk, which can be obtained from various animal sources but commonly comes from cows. Casein and whey proteins are the two main families of proteins found in milk.

Step-by-step summary of industrial production process.

• Milk collection. Milk is milked from animals and collected in sterile containers.
• Cream-skim milk separation. The milk is separated into cream and skim milk using centrifugation.
• Coagulation and separation. The milk is coagulated (for casein proteins) and the curd is separated from the whey.
• Protein extraction. Proteins (either casein or whey) are further separated and isolated through various processes like filtration, diafiltration, or electrodialysis.
• Drying. The isolated proteins are then dried to produce a protein powder.

Form and color. 

Proteins derived from milk are generally available in powder form, which can range from white to yellowish, depending on the type and production process.

Commercial applications. 

Milk proteins are used in various food products, including protein supplements, functional foods, baked goods, and more, owing to their excellent functional and nutritional properties.

Dietary Supplements. Milk proteins, like casein and whey, are often used in powdered form as dietary supplements, especially for those engaged in sports activities, to promote muscle growth and repair.

Functional Foods. Used in functional foods and beverages to enrich protein content, like in protein shakes or certain baked goods.

Dairy Industry. Used in the production of cheeses and other dairy products.

Cosmetic Products. Milk proteins are also utilized in some cosmetic products for their moisturizing and nourishing properties.

Safety

Milk proteins do not inherently contain lactose, but in dairy products, they are typically present alongside it. Milk consists of several components, including water, fats, proteins, lactose (a sugar), and minerals. The primary proteins in milk are casein and whey, and these proteins themselves do not contain lactose. However, in the context of milk and many milk-derived products, lactose is present along with these proteins.

It's essential to note that some milk-derived protein products, like whey protein powder, can contain some lactose, depending on how they were processed. For example:

Whey Protein Isolate: Contains minimal lactose because most of it is removed during processing.

Whey Protein Concentrate: Can contain varying amounts of lactose.

People who are lactose intolerant might opt for lactose-free milk products or might use lactase supplements to help digest lactose found in milk products. Always check the nutritional information and ingredients on product labels if lactose content is a concern.

Pharmaceutical Products. Milk proteins might have applications in the pharmaceutical field, such as vehicles for drug delivery or for their nutritional properties in supplements.

Studies

Milk proteins are separated into two main groups: casein (~ 80%) and whey protein (~ 20%) (1)

However, it is a product that can give rise to allergic reactions (2) which is on the increase lately even in babies and children. As for the cause that can cause these allergies, it was discovered that it could be maize, or better, a protein of glucose of corn starch (3).

Other studies on milk proteins

References_______________________________________________________________________

(1) Sato ACK, Perrechil FA, Costa AAS, Santana RC, Cunha RL. - Cross-linking proteins by laccase: Effects on the droplet size and rheology of emulsions stabilized by sodium caseinate. -  Food Res Int. 2015 Sep;75:244-251. doi: 10.1016/j.foodres.2015.06.010. Epub 2015 Jun 12. 

(2) EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) -  Scientific Opinion on Dietary Reference Values for protein --  First published: 9 February 2012

(3) Cow's milk protein intolerance in adolescents and young adults with chronic fatigue syndrome. - Rowe PC, Marden CL, Jasion SE, Cranston EM, Flaherty MA, Kelly KJ. - Acta Paediatr. 2016 Sep

(4) Jirapinyo P, Densupsoontorn N, Kangwanpornsiri C, Wongarn R, Tirapongporn H, Chotipanang K, Phuangphan P. - Improved Tolerance to a New Amino Acid-Based Formula by Infants With Cow's Milk Protein Allergy. - Nutr Clin Pract. 2016 Apr

Sah BN, Vasiljevic T, McKechnie S, Donkor ON. - Antioxidative and Antibacterial Peptides Derived from Bovine Milk Proteins. -  Crit Rev Food Sci Nutr. 2016 Aug.