Above all, we are going to define milk as an emulsion or colloid of nutritional substances in an aqueous solution.
It is the first food of all mammalian animals, therefore we understand that it is a complex food. It contains an incalculable amount of substances that make it impossible to reproduce it in a laboratory.
What is milk made of?
For our purposes it would not make sense at this time to list all the ingredients of raw cow’s milk. Firstly because each mammal female has their own composition.
Secondly because the conservation or thermal treatments of the milk can alter their properties and composition.
Alternatively we can talk about milk’s main components that we use to make cheese:
Water is milk’s most important ingredient. It represents around 90% of the milk.
The entire cheese-making process is aimed at removing the water. The amount of water that we eliminate and the moment in which we do it, will allow us to make completely different cheeses.
Lactose is the most important carbohydrate in the milk taste because gives it its sweet taste and contributes approximately 40% of whole cow’s milk’s calories, too.
In cheesemaking, It’s the ingredient that allows us to select the microbiology that will develop our cheese.
Lactose is a disaccharide composite of two simple sugars, glucose and galactose.
A lactose is a molecule of galactose linked to one of glucose Proteins
Milk contains two clearly differentiated proteins:
Caseins are the most important and make up around 80% of the protein in milk, by weight. Most of the casein proteins are bound into the micelles. Lactoglobulin make up approximately 20% of the protein in milk by weight. They are soluble in water, and in the end of process will be in whey
The different types of caseins come together in units called casein micelles. Lipids
Milk fat is secreted in the form of a fat globule surrounded by a membrane. Although 97–98% of lipids are triacyclglycerols, small amounts of di- and monoacylglycerols, free cholesterol and cholesterol esters, free fatty acids, and phospholipids are also present
A triglyceride (TG) molecule consists of a glycerol backbone esterified with three fatty acids Minerals
Calcium, phosphate, magnesium, sodium, potassium, citrate, and chlorine are some of the most important minerals present in milk.
Calcium and phosphorus are the two most important minerals in cheese making Microbiology
Milk microbiology comes from milking cows on the dairy and from the environment itself.
A large number of microorganisms in dairy products come from the milk itself Vitamins
Milk is a good source of many other vitamins. Vitamins A, B6, B3, B12, C, D, K, E, thiamine, niacin, biotin, riboflavin, folates, and pantothenic acid
The composition of milk varies depending on the species. Below is a table summarizing the contents and characteristics of milk, depending on the mammal producer.