There are a lot more chemicals in milk than you might expect. As a naturally-occuring baby and infant food for mammals, it’s rich in protein, fats, lactose, vitamins, and minerals that are essential for growth and development. Even in adulthood and old age, milk is still an important substance in our diet.
In this post:
A Complete List of Chemicals in Milk
The exact composition of chemicals in milk varies, depending on the natural source or artificial formulation. For example, some commercially available infant formula milk brands are fortified with vitamins and minerals that aren’t normally available in natural cow’s milk.
While most of the chemicals in milk have nutritional value, some don’t offer any form of nutrition, such as in the case of commercially available milk brands, which include artificial additives like food colouring, preservatives, and synthetic sweeteners in their products.
However, the majority of naturally occurring chemicals found in cow’s milk are the following:
- Moisture/water (87%): The main constituent of milk is water, which serves as the solvent and colloidal medium for all other chemicals, including vitamins.
- Fat (3.9%): Otherwise known as lipids, the different types of fats in milk include triacylglycerides, diacylglycerides, saturated and polyunsaturated fatty acids, and phospholipids. Also present are fat-soluble vitamins, vitamin A, vitamin D, vitamin E, and vitamin K (phytomenadione). Of the twelve major types of fatty acids found in milk, only three (lauric, myristic, and palmitic) are associated with increasing the cholesterol levels in blood plasma.
- Proteins (3.4%): Casein and whey proteins form the majority of proteins found in cow’s milk. Casein comprises around 80% of the protein in milk, while approximately 20% are whey proteins (see more on casein below). Casein is primarily phosphate-conjugated and is mainly composed of calcium phosphate, known as micelle complexes. Other types of proteins in milk are various kinds of enzymes in trace amounts.
- Lactose (4.8%): Lactose is a type of sugar classified as a disaccharide. It’s composed of two sugar subunits: galactose and glucose. The chemical formula for lactose is C12H22O11. Some people are incapable of digesting lactose. These people typically experience upset stomachs when they drink milk or eat dairy products like cheese. This intolerance is actually an evolutionary throwback: lactose intolerant adults don’t have the mutation that allows for the production of an enzyme called lactase, which digests lactose.
- Minerals (0.8%): The bones, teeth, blood, nerves, and muscles all need one or more types of minerals to maintain their structure and function properly. For example, calcium is necessary for bone growth and for heart contraction. Milk has traces of various minerals in edible, digestible forms. The major minerals found in milk are calcium, sodium, potassium, iron, magnesium, and phosphorus. Milk also contains trace amounts of other minerals such as iodine, fluorine, chlorine, zinc, cobalt, and selenium.
Most types of milk on the market, whether powdered or fresh, are derived from cow’s milk. These days, there are also many plant-based and non-dairy alternatives, like soya and almond milk. Technically, these aren’t classified as milk, but they contain similar nutrients as real milk.
Other less popular types of milk (especially in the UK) are water buffalo’s milk, goat’s milk, sheep’s milk, and camel’s milk. Dairy products such as cheese, butter, ice cream, and yogurt can also be derived from these various types of milk.

Nutritional Components (Proteins, Fats, Carbohydrates)
Milk contains many essential nutrients that the body needs based on the food pyramid. It contains ‘grow food’ nutrients, ‘go food’ nutrients, and ‘glow food’ nutrients.
The ‘grow food’ nutrients include proteins, which are mainly (about 80%) casein and whey (about 20%). These are composed of the essential amino acids that can be used by the body to produce new types of proteins such as actin and myosin of the skeletal muscles.
Milk also contains ‘go’ and ‘glow’ nutrients. The carbohydrates, like lactose and fat, are ‘go’ nutrients which are metabolised by the body as a source of energy and as storage for energy.
There are also significant amounts of ‘glow’ nutrients in milk in the form of vitamins and minerals. Hence, milk is considered by many as a complete food.
Vitamins and Minerals
Milk contains micronutrients (vitamins and minerals) that are essential as coenzymes and components of body tissues.
The most important of these vitamins are vitamin B2 and the fat-soluble vitamins, A (retinol), D (calciferol), and E (alpha-tocopherol).
Milk also contains traces of minerals, the most important of which is calcium. Calcium forms an essential part of the structure of bones and teeth.
What Chemical Preservatives Are Used in Milk?
Fresh milk undergoes a pasteurisation process. Even still, the lifespan or storage life of fresh milk is very short. Even under ideal refrigeration conditions, pasteurised milk only lasts between two to five days.
To remedy the relatively short shelf life of milk, large food processing and manufacturing companies make powdered milk and modified liquid milk, like condensed milk. These products have preservatives that prevent spoilage even long after they’re opened. Powdered milk products, for example, don’t need refrigeration. You only need to make sure the container is airtight because prolonged exposure to open air can ruin the product.
So, while fresh milk typically doesn’t have any artificial preservatives, other forms of milk, like powdered milk, evaporated milk, and condensed milk, contain chemical preservatives to make them last. The major types of preservatives used are:
- Sodium benzoate (C7H5NaO2)
- Potassium sorbate (C6H7KO2)
- Natamycin (C33H47NO13)
- Calcium propionate (C6H10CaO4)
- Sorbic acid (C6H8O2)
- Ascorbic acid (C6H8O6)
- Sucrose (C12H22O11)
Most of these preservatives are either antifungal or antibacterial. Some are even antioxidants, like ascorbic acid, otherwise known as vitamin C. This is usually added as a supplement, but it also prevents the oxidation of milk components. Some preservatives, like sucrose, also function as adulterants or extenders.

Common Preservatives
Fresh milk from cows, sheep, goats, and other animals is processed to remove any possible pathogens.
It’s typically subjected to pasteurisation to kill the microorganisms without denaturing the protein structures of milk. Typically, fresh milk is subjected to a temperature of 63°C for 30 minutes.
However, to ensure longer shelf life, preservatives such as potassium sorbate, sodium benzoate, and natamycin are commonly added to milk.
Regulatory Standards and Safety
In the UK, there are several regulations covering the processing, handling, storing, and transporting of milk. These regulations are implemented by the Food Standards Agency and are largely influenced by European standards.
For example, the animal from which raw milk is extracted must not have any disease and must be in a good state of health. It is also mandated that the raw milk must be cooled immediately at 8oC if it is collected daily.
Are Chemicals in Milk Dangerous?
While milk can be dangerous to those who are lactose intolerant, the chemicals in milk are perfectly safe for most people. There is nothing toxic or dangerous about the chemicals in milk unless the milk has spoiled, which could cause food poisoning.
While different types of processed milk contain preservatives and adulterants, these are well-regulated by the Food Standards Agency (FSA) in the UK.
Spoiled milk and lactose intolerance aside, the only real danger of drinking milk or eating dairy products is milk allergy. Put simply, some people are just allergic to milk. These people may experience vomiting, wheezing, hives, digestive problems, and possible anaphylaxis, which can be life threatening.
For people who aren’t lactose intolerant and don’t have any allergies, drinking milk in moderation is safe and healthy.
Potential Health Risks
The potential health risks of raw or fresh milk mainly include microbial and parasitic contaminations, which occur if the animal source is infected with pathogens.
It’s these pathogens which can cause diarrhoea and even food poisoning. Raw milk contains many dangerous bacteria, such as Salmonella, E. coli, Campylobacter, and Staphylococcus aureus, which can cause a variety of diseases – it may also contain parasites.
Another health risk is an intolerance or an allergic reaction to milk, as some people are sensitive to the proteins it contains.
Safe Consumption Levels
Milk contains nutrients that are essential to our metabolism and general health. There are recommended daily allowance of these nutrients. These vary depending on your age, sex, BMI, and health condition.
For example, older people may need higher daily intake of milk products that have high calcium content to help avoid osteoporosis. It’s best to consult a nutritionist but generally, the RDA on a label of milk will suffice.
What is Casein?
Casein is the main type of protein found in mammalian milk. In cow’s milk, for instance, casein forms 80% of all the protein it contains. The remaining 20% is whey protein. However, casein only forms between 20% and 60% of the proteins found in human milk. Sodium caseinate is the most prevalent form of casein. Casein is a good source of amino acids, carbohydrates, and two essential nutritional elements: calcium and phosphorus.
What’s the Chemical Formula for Casein in Milk?
In milk, casein takes the form of colloidal particles known as casein micelles. These are polydisperse (or of various sizes), large, and roughly spherical in shape – between approximately 50 and 600 nanometers in diameter.
Casein is a relatively simple protein molecule with a high number of proline amino acids. This hinders the formation of secondary structural folds or motifs. The molecule also has no disulfide bridges, which makes it difficult to form tertiary structures.
The chemical formula for casein can be written as C81H125N22O39P. Meanwhile, the molecular structure can be illustrated as:

Conclusion
Milk is a nutritious natural food. It contains many essential nutrients, such as proteins, carbohydrates, vitamins, and minerals, ideal for both children and adults. Milk has complex biochemical compositions that provide nourishment and energy. However, raw milk especially offers some risk. It must undergo a pasteurisation process to kill the germs without denaturing the proteins of milk. There are also other health risks, such as lactose intolerance and allergies.