What substances are used to make milk?

Milk is a complex fluid secreted by mammary glands in female mammals. It provides essential nutrients to infant mammals, including water, carbohydrates, proteins, fats, vitamins and minerals. The composition of milk can vary depending on the mammal, but the primary substances used to make milk are:

- Water: Water makes up the largest component of milk, typically accounting for around 87% of its total volume.

- Lactose: Lactose is a sugar that is found only in milk and milk products. It is a disaccharide composed of galactose and glucose molecules linked together. Lactose provides energy and contributes to the sweet taste of milk.

- Proteins: The proteins in milk are primarily casein proteins, which account for about 80% of the total protein content. Casein proteins are essential for the formation of the milk curd when milk is coagulated with an acid or rennet. Other proteins found in milk include whey proteins, such as alpha-lactalbumin and beta-lactoglobulin.

- Fats: Milk fats are made up of various fatty acids, including saturated, monounsaturated and polyunsaturated fats. The fatty acid composition of milk fats can vary depending on the type of mammal, diet, and other factors.

- Vitamins: Milk contains a range of vitamins, including vitamin A, vitamin C, vitamin D, vitamin E, and vitamins B1, B2, B3, B5, B6, B7, B9 and B12.

- Minerals: Milk is a good source of various minerals, including calcium, phosphorus, potassium, magnesium, zinc and iron.

In addition to these main substances, milk may also contain trace elements of other compounds such as enzymes, hormones, growth factors, and bioactive peptides. The composition of milk can also be influenced by factors such as the breed of mammal, stage of lactation, and diet.