Deconstructing the Main Chemical Properties of Milk

The Chemical Properties and Differences in Milk

The five major properties of milk are water, fat, proteins, lactose (milk sugar) and minerals such as salts. Cow's milk typically consists of 87% water, but it also contains 13% dry substances and droplets of emulated fat suspended in a solution, this is also known as a colloid. A colloid is a mixture where very small particles of one substance are evenly distributed throughout the other substance. Milk fat is a non-polar molecule, so it will not dissolve in water. Milk and cream are both examples of fat-in-water emulsions. Emulsions are disbursements of one substance into water; for the example of milk it would be fat or oils dispersing into water. The milk fat consists dominantly of triglycerides, di and monoglycerides, fatty acids, sterols, carotenoids which gives milk the yellow-toned color. Milk fat is a mixture of different fatty-acid esters called triglycerides which are composed of an alcohol called glycerol and various fatty acids. Glycerides are the major proponent in milk fat and make up 99% of it (Chemistry of Milk).

There are also less prevalent substances such as pigments, enzymes, vitamins, phospholipids, which are substances with fat like properties, and gases. Milk is one of the easiest ways to get naturally nutrient rich substances into your body. It consists of nine essential nutrients such as: B vitamins which convert food to energy, high-quality protein for promotion of lean muscles, Vitamin A for a healthy immune system, potassium for regulating the balance of fluids and phosphorus calcium D for bone building (Milk Life).

When you are shopping for milk, you are typically presented with a lot of different options (whole milk 3.25%, reduced-fat milk 2%, low fat milk 1%, and fat free milk). There is no difference in the amount of protein or calcium in these different types of milk, however, what is different is the fat percentages.Whole Milk is by far the most popular among Americans. Surprisingly, it actually does not have as much fat as most people think, with only 3.25% milkfat (glycerides), there are 150 calories in an 8-ounce glass and 8 grams of fat (MilkLife) Reduced Fat Milk, or 2% Milk has milkfat of 2% of the total weight of the milk - not that there is 2% fat per each 8 ounce serving. In fact, 2% milk has only 5 grams of fat and the same nutrients that whole milk does. Low Fat Milk or 1% is exactly half of what 2% is. An 8 ounce serving of lowfat milk contains 2.5 grams of fat and 100 calories. Whole milk on the other hand has 8 grams of fat and 150 calories (USDA).

If a person is interested in getting all of the nutrients that milk provides but does not want the calories that comes along, then fat free or skim milk is the best option. Because it has the least amount of fat, there are only 80 calories per 8-ounce serving. Many people believe that skim milk is diluted with water to reduce the fat content but that is incorrect. As it turns out, the largest difference between types of milk is not the amount of protein per serving, but the calories due to fat per serving. It is clear that the only difference between the types of milk are the amount of glycerol triglycerides included in the final product. The more milk fat a gallon of milk has, the higher percentage on the label, and thus, the less modified it is.