Powdered milk is a manufactured
dairy productDairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...
made by evaporating
milkMilk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
to
drynessDrying is a method of food preservation that works by removing water from the food, which inhibits the growth of microorganisms and hinders quality decay. Drying food using sun and wind to prevent spoilage has been practised since ancient times, and was the earliest form of food curing...
. One purpose of drying milk is to preserve it; milk powder has a far longer
shelf lifeShelf life is the length of time that food, drink, medicine, chemicals, and many other perishable items are given before they are considered unsuitable for sale, use, or consumption...
than liquid milk and does not need to be
refrigeratedRefrigeration is a process in which work is done to move heat from one location to another. This work is traditionally done by mechanical work, but can also be done by magnetism, laser or other means...
, due to its low moisture content. Another purpose is to reduce its bulk for economy of transportation. Powdered milk and dairy products include such items as dry whole milk, nonfat dry milk, dry buttermilk, dry
wheyWhey or Milk Serum is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. Sweet whey is manufactured during the making of rennet types of hard cheese like cheddar or Swiss cheese...
products and dry dairy blends. Many dairy products exported conform to standards laid out in
Codex AlimentariusThe Codex Alimentarius is a collection of internationally recognized standards, codes of practice, guidelines and other recommendations relating to foods, food production and food safety. Its name derives from the Codex Alimentarius Austriacus...
.
Powdered milk is used for food and health (
nutritionNutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....
), and atypically also in
biotechnologyBiotechnology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine and other fields requiring bioproducts. Biotechnology also utilizes these products for manufacturing purpose...
(saturating agent).
History and manufacture
While
Marco PoloMarco Polo was a Venetian merchant traveler from the Venetian Republic whose travels are recorded in Il Milione, a book which did much to introduce Europeans to Central Asia and China. He learned about trading whilst his father and uncle, Niccolò and Maffeo, travelled through Asia and apparently...
wrote of
MongolianMongols ) are a Central-East Asian ethnic group that lives mainly in the countries of Mongolia, China, and Russia. In China, ethnic Mongols can be found mainly in the central north region of China such as Inner Mongolia...
Tatar troops in the time of
Kublai KhanKublai Khan , born Kublai and also known by the temple name Shizu , was the fifth Great Khan of the Mongol Empire from 1260 to 1294 and the founder of the Yuan Dynasty in China...
who carried sun-dried skimmed milk as "a kind of paste," the first usable commercial production process for dried milk was invented by the Russian chemist M. Dirchoff in 1832. In 1855, T.S. Grimwade took a patent on a dried milk procedure, though a William Newton had patented a vacuum drying process as early as 1837.
In modern times, powdered milk is usually made by
spray dryingSpray drying is a method of producing a dry powder from a liquid or slurry by rapidly drying with a hot gas. This is the preferred method of drying of many thermally-sensitive materials such as foods and pharmaceuticals. A consistent particle size distribution is a reason for spray drying some...
nonfat skim milk, whole milk, buttermilk or whey.
PasteurizedPasteurization is a process of heating a food, usually liquid, to a specific temperature for a definite length of time, and then cooling it immediately. This process slows microbial growth in food...
milk is first concentrated in an
evaporatorAn evaporator is a device used to turn the liquid form of some chemical into its gaseous form. For example, an evaporator is used in an air conditioning system to allow the compressed cooling chemical to evaporate from liquid to gas, absorbing heat in the process.-Uses:As stated above, an...
to approximately 50% milk solids. The resulting concentrated milk is then sprayed into a heated chamber where the water almost instantly evaporates, leaving fine particles of powdered milk solids.
Alternatively, the milk can be dried by
drum dryingDrum drying is a method used for drying out liquids; for example, milk is applied as a thin film to the surface of a heated drum, and the dried milk solids are then scraped off with a knife...
. Milk is applied as a thin film to the surface of a heated drum, and the dried milk solids are then scraped off. However, powdered milk made this way tends to have a cooked flavor, due to
caramelizationCaramelization is the browning of sugar, a process used extensively in cooking for the resulting nutty flavor and brown color. As the process occurs, volatile chemicals are released, producing the characteristic caramel flavor....
caused by greater heat exposure.
Another process is
freeze dryingFreeze-drying is a dehydration process typically used to preserve a perishable material or make the material more convenient for transport...
, which preserves many nutrients in milk, compared to drum drying.
The drying method and the heat treatment of the milk as it is processed alters the properties of the milk powder, such as its solubility in cold water, its flavor, and its
bulk densityBulk density is a property of powders, granules and other "divided" solids, especially used in reference to mineral components , chemical substances, ingredients, foodstuff or any other masses of corpuscular or particulate matter. It is defined as the mass of many particles of the material...
.
Food and health uses
Powdered milk is frequently used in the manufacture of
infant formulaInfant formula is a manufactured food designed and marketed for feeding to babies and infants under 12 months of age, usually prepared for bottle-feeding or cup-feeding from powder or liquid . The U.S...
,
confectioneryConfectionery is the set of food items that are rich in sugar, any one or type of which is called a confection. Modern usage may include substances rich in artificial sweeteners as well...
such as chocolate and caramel candy, and in recipes for baked goods where adding liquid milk would render the product too thin. Powdered milk is also widely used in various sweets such as the famous Indian milk balls known as Rasa-Gulla and popular Indian sweet delicacy (sprinkled with desiccated coconut) known as Chum chum (made with skim milk powder).
Powdered milk is also a common item in
UN food aidThe World Food Programme is the food aid branch of the United Nations, and the world's largest humanitarian organization addressing hunger worldwide. WFP provides food, on average, to 90 million people per year, 58 million of whom are children...
supplies, fallout shelters, warehouses, and wherever fresh milk is not a viable option. It is widely used in many developing countries because of reduced transport and storage costs (reduced bulk and weight, no refrigerated vehicles). As with other dry foods, it is considered nonperishable, and is favored by
survivalistsSurvivalism is a movement of individuals or groups who are actively preparing for future possible disruptions in local, regional, national, or international social or political order...
,
hikersHiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...
, and others requiring nonperishable, easy-to-prepare food.
Due to its resemblance to
cocaineCocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
and other drugs, powdered milk is sometimes used in
filmmakingFilmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...
as a non-toxic
propA theatrical property, commonly referred to as a prop, is an object used on stage by actors to further the plot or story line of a theatrical production. Smaller props are referred to as "hand props". Larger props may also be set decoration, such as a chair or table. The difference between a set...
that may be
inhaledInsufflation is the practice of inhaling a substance. Insufflation has limited medical use, but is a common route of administration with many respiratory drugs used to treat conditions in the lungs and paranasal sinus .The technique is common for many recreational drugs and is also used for some...
in lieu of the genuine article.
Reconstitution
The weight of nonfat dry milk (NFDM) to use is about 10% of the water weight. Alternatively, one cup of potable fluid milk from powdered milk requires one cup of potable water and one-third cup of powdered milk.
Nutritional value
AMANur Milk powders contain all twenty-one standard amino acids, the building blocks of
proteinProteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s, and are high in soluble vitamins and
mineralsDietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. Examples of mineral elements include calcium, magnesium, potassium, sodium, zinc, and iodine...
. According to USAID, the typical average amounts of major nutrients in the unreconstituted nonfat dry milk are (by weight) 36% protein, 52% carbohydrates (predominantly
lactoseLactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...
), calcium 1.3%, potassium 1.8%. Whole milk powder, on the other hand, contains on average 25-27% protein, 36-38% carbohydrates, 26-40% fat, and 5-7% ash (minerals). However, such inappropriate storage conditions as high relative humidity and high ambient temperature can significantly degrade the nutritive value of milk powder.
Commercial milk powders are reported to contain oxysterols (oxidized cholesterol) in higher amounts than in fresh milk (up to 30 μg/g, versus trace amounts in fresh milk).
Oxysterols are derivatives of cholesterol that are produced either by free radicals or by enzymes. Certain free radicals-derived oxysterols have been suspected of being initiators of
atherosclerotic plaquesAtherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
. For comparison,
powdered eggsPowdered eggs are fully dehydrated eggs. They are made in a spray dryer in the same way that powdered milk is made. The major advantages of powdered eggs over fresh eggs are the price, reduced weight per volume of whole egg equivalent, and the shelf life...
contain even more oxysterols, up to 200 μg/g.
Export market
European production of milk powder is estimated around 800.000 tons of which the main volume is exported in bulk packing or consumer packs.
Brands on the market include "
NidoNIDO is a powdered milk supplement manufactured by Nestlé. Although there is no age recommendation, marketing is featured around children over three years of age with the tagline "Nutritious Milk for Growing Kids"...
", from the company
NestléNestlé S.A. is the world's largest food and nutrition company. Founded and headquartered in Vevey, Switzerland, Nestlé originated in a 1905 merger of the Anglo-Swiss Milk Company, established in 1867 by brothers George Page and Charles Page, and Farine Lactée Henri Nestlé, founded in 1866 by Henri...
, "Incolac" from the company Belgomilk, and "Dutch Lady" from FrieslandCampina.
Adulteration
In the
2008 Chinese milk scandalThe 2008 Chinese milk scandal was a food safety incident in the People's Republic of China, involving milk and infant formula, and other food materials and components, adulterated with melamine....
,
melamineMelamine is an organic base and a trimer of cyanamide, with a 1,3,5-triazine skeleton. Like cyanamide, it contains 66% nitrogen by mass and, if mixed with resins, has fire retardant properties due to its release of nitrogen gas when burned or charred, and has several other industrial uses....
adulterantAn adulterant is a chemical substance which should not be contained within other substances for legal or other reasons. Adulterants may be intentionally added to more expensive substances to increase visible quantities and reduce manufacturing costs or for some other deceptive or malicious purpose...
was found in Sanlu
infant formulaInfant formula is a manufactured food designed and marketed for feeding to babies and infants under 12 months of age, usually prepared for bottle-feeding or cup-feeding from powder or liquid . The U.S...
, added to fool tests into reporting higher protein content. Thousands became ill, and some children died, after consuming the product.
Use in biotechnology
Fat-free powder milk is used as a saturating agent to block nonspecific binding sites on supports like
blottingIn molecular biology and genetics, a blot is a method of transferring proteins, DNA or RNA, onto a carrier . In many instances, this is done after a gel electrophoresis, transferring the molecules from the gel onto the blotting membrane, and other times adding the samples directly onto the membrane...
membranes (
NitrocelluloseNitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
, PVDF,
NylonNylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
), preventing binding of further detection reagents and subsequent background. It may be referred as
BlottoIn biology, BLOTTO is a blocking reagent made from nonfat dry milk, phosphate buffered saline, and sodium azide. Its name is an acronym of Bovine Lacto Transfer Technique Optimizer. It constitutes an inexpensive source of nonspecific protein which blocks protein binding sites in a variety of...
. The major
proteinProteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
of milk,
caseinCasein is the name for a family of related phosphoprotein proteins . These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 60% and 65% of the proteins in human milk....
, is responsible of most of the binding site saturation effect.
See also
- Baked milk
Baked milk is a variety of boiled milk that has been particularly popular in Russia and Ukraine. It is made by simmering milk on low heat for eight hours or longer....
- Coconut milk powder
Coconut milk powder is an ingredient in most Southeast Asian cooking and is not the liquid inside a coconut. It is prepared by soaking the grated flesh of a coconut in hot water or scalded milk, then straining the combination. Coconut milk is classified as thick, thin, or coconut cream. Thick...
- Condensed milk
Condensed milk, also known as sweetened condensed milk, is cow's milk from which water has been removed and to which sugar has been added, yielding a very thick, sweet product which when canned can last for years without refrigeration if unopened. The two terms, condensed milk and sweetened...
- Evaporated milk
Evaporated milk, also known as dehydrated milk, is a shelf-stable canned milk product with about 60% of the water removed from fresh milk. It differs from sweetened condensed milk, which contains added sugar. Sweetened condensed milk requires less processing since the added sugar inhibits ...
- Scalded milk
Scalded milk is milk that has been heated to . At this temperature, bacteria and enzymes in the milk are destroyed. Since most milk sold today is pasteurized, which accomplishes both of these goals, milk is typically scalded simply to increase its temperature, or to change the consistency due to...