One of the major food groups, dairy products are popular ingredients in many different foods. Put simply, a dairy product is any food made from the milk products of animals or produced in the mammary glands. The most common of dairy products are obtained from cows, who are often the prime producer of dairy products.
Human milk is relatively low in both proteins and minerals compared with that of cows and goats.
Cow milk is also used in the production of creams, cheeses, and desserts. However, dairy products are not mutually exclusive to cows as we also obtain milk from goats and sheep, as well as other mammals in many countries. Even though the sap from trees is classified as "milk", this "milk" is very high in proteins and is not counted under the same group.
Nutrient Composition of Dairy Products
The composition of milk varies among mammals, primarily owing to the growth rates of the individual species. The major component for growth in young animals is the protein content in milk. The other major components of milk are water, fat, protein, carbohydrate (lactose), and minerals (ash). Moreover, there are numerous other essential micronutrients such as vitamins, essential amino acids, and trace minerals. More than 250 chemical compounds have been identified in milk.
The fat in milk is secreted by specialized cells in the mammary glands of mammals. It is released as tiny fat globules or droplets, which are stabilized by a phospholipid and protein coat derived from the plasma membrane of the secreting cell. Milk fat is composed mainly of triglycerides — three fatty acid chains attached to a single molecule of glycerol.
Milk contains 65 percent saturated, 32 percent monounsaturated, and 3 percent polyunsaturated fatty acids. The fat droplets carry most of the cholesterol and vitamin A. This is why skim milk, which has more than 99.5 percent of the milk fat removed, is significantly lower in cholesterol than whole milk and must be fortified with vitamin A.
Milk contains a number of different types of proteins, depending on what is required for sustaining the young of the particular species. These proteins increase the nutritional value of milk and other dairy products and provide certain characteristics utilized for many of the processing methods.
A major milk protein is casein which actually exists as a multisubset protein complex dispersed throughout the fluid phase of milk. Under certain conditions, the casein complexes are disrupted, causing curdling of the milk. Curdling results in the separation of milk proteins into two distinct phases — a solid phase (the curds) and a liquid phase (the whey).
Lactose is the principal carbohydrate found in milk. It is a disaccharide composed of one molecule each of the monosaccharides (simple sugars) glucose and galactose. Lactose is an important food source for several types of fermenting bacteria. The bacteria convert lactose into lactic acid, which is the basis for several types of dairy products.
In the diet, lactose is broken down into its component glucose and galactose subunits by the enzyme lactase. The glucose and galactose can then be absorbed from the digestive tract for use by the body. Individuals deficient in lactase cannot metabolize lactose, a condition called lactose intolerance.
Vitamins and Minerals
Milk is an excellent source of many vitamins. However, its vitamin C (ascorbic acid) content is easily destroyed by heating during pasteurization. Vitamin D is formed naturally in milk fat by ultraviolet irradiation but not in sufficient quantities to meet human nutritional needs. Beverage milk is commonly fortified with fat-soluble vitamins A and D.
Milk also provides many of the B vitamins. It is an excellent source of riboflavin (B2) and provides some amounts of thiamine (B1) and niacin. Other B vitamins found in trace amounts are pantothenic acid, folic acid, biotin, pyridoxine (B6), and vitamin B12. Milk is also rich in minerals and is a source of calcium and phosphorus. It also contains trace amounts of potassium, chloride, sodium, magnesium, sulfur, copper, iodine, and iron.
Dairy Food Recommendations
Like fruits and vegetables, consumers are spoiled for nutrient choices when it comes to dairy products as there is such a wide range of them. Check out the nutrition information on the label to check the amount of fat, including saturated fat, salt, and sugar, in the dairy products you are buying. Here is a complete breakdown of the types of dairy products out there and our top picks in dairy food recommendations.
- Liquid milk: The most consumed, processed, and marketed dairy product, liquid milk includes products such as pasteurized milk, skimmed milk, standardized milk, reconstituted milk, ultra-high-temperature (UHT) milk, and fortified milk.
- Fermented milk: Commonly used to make other milk products, fermented milk is obtained from the fermentation of milk using suitable microorganisms to reach a desired level of acidity. Fermented products include yogurt, koumiss, dahi, labneh, ergo, tarag, kraut, and kefir.
- Cheese: Produced through the coagulation of milk protein (casein), which is separated from the milk’s whey, there are hundreds of varieties of cheese, many of them being characteristic to a particular region of the globe. Cheese can be soft, hard, semi-hard, hard ripened, or unripened. Cheese’s diverse characteristics are derived from differences in the compositions and types of milk, processes applied, and microorganisms used. Traditional cheeses include ayib, gibna bayda, chanco, queso fresco, akawieh, and chhurpi.
- Butter and ghee: These are fatty milk products that are produced by churning milk or cream. Traditional butter is obtained by churning sour whole milk. Ghee is obtained by removing the water from butter and is especially popular in South Asia. Ghee has a very long shelf-life of up to two years.
- Condensed milk: This is obtained from the partial removal of water from whole or skimmed milk. Processing includes heat-treating and concentration. Condensed milk can be sweetened or unsweetened, but most are sweetened. In Latin America, for example, condensed milk is often used in cooking and baking instead of jam.
- Evaporated milk: This is obtained from the partial removal of water from whole or skimmed milk. Processing includes heat-treating to make the milk bacteriologically safe and stable. Evaporated milk is generally mixed with other foods, such as milky tea.
- Dry milk or milk powder: This is obtained from the dehydration of milk and is usually in the form of powder or granules.
- Cream: This is comparatively rich in milk fat. Cream is extracted by skimming or centrifuging the milk. Cream products include recombined cream, reconstituted cream, prepared creams, pre-packaged liquid cream, whipping cream, cream packed under pressure, whipped cream, fermented cream, and acidified cream.
- Whey products: According to FAOSTAT, whey is “the liquid part of the milk that remains after the separation of curd in cheese making. Its main food use is in the preparation of whey cheese, whey drinks, and fermented whey drinks. The main industrial uses are in the manufacture of lactose, whey paste, and dried whey.” Whey can be sweet (from the production of rennet-coagulated cheeses) or acid (from the production of acid-coagulated cheeses).
- Casein: This is the principal protein in milk and is used as an ingredient in several products, including cheese, bakery products, paints, and glues. It is extracted from skimmed milk by precipitation with rennet or by harmless lactic acid-producing bacteria.
Learn About Diary Alternatives
Many of us have had issues digesting milk and milk products. Here is a list of easy alternatives for some of the most popular dairy products. But remember to consult certified nutritionists in India before you settle on your kind of dairy alternative!
- Milk: Almond milk, coconut milk beverage (not to be confused with coconut milk that comes in cans; check to ensure they are protein- and calcium-fortified) and calcium-fortified soy, rice, and other cereal drinks
- Butter: Dairy-free margarine, cooking or baking oils, fruit purees for baking, nutritional yeast for flavor, coconut butter
- Cheese: Nutritional yeast, tofu
- Chocolate: Dark or semi-sweet chocolate, dairy-free ‘milk’ chocolate, white chocolate, or pure chocolate (100% cocoa or cacao chocolate)
- Cream: Coconut milk, milk alternatives, dairy-free margarine, silken tofu, oils, nuts, and seeds
- Yogurt: Buttermilk alternative, coconut cream, homemade dairy-free yogurt, pureed silken tofu, sour cream alternative
How Much Dairy Intake is Enough?
Certified nutritionists in India are the best people to tell you how much dairy, or its alternatives, is good for your health. The amount of dairy you need depends on your age, sex, height, weight, and level of physical activity. For example, pregnant or breastfeeding women may need higher amounts of dairy in their bodies than the average woman.
Consuming dairy products provides many health benefits, especially in building and maintaining strong bones. Dairy foods are rich in vital nutrients, such as calcium, potassium, vitamin D, and protein. Calcium and vitamin D are important nutrients for people across all age groups. Consumption of dairy products improves bone health, especially in children and adolescents. Moreover, dairy products help to prevent the onset of osteoporosis in adults, most of whom lack the basic nutrients.
The platform that connects tutors and students