The Babcock test is an inexpensive and practical procedure to determine the fat content of milk. It is named after its developer, Stephen M. Babcock (1843–1931), professor at the University of Wisconsin.
The bottle and the test were developed by Stephen Babcock in 1890 as a simple but accurate way to detect adulterations practiced by some dairy farmers, including diluting the milk with water or skimming some cream.
The test was quickly adopted by dairymen, and also by farmers to help the breeding of milk cows. [ citation needed ] Babcock's refusal to patent his process or the device greatly helped its widespread diffusion.The tests were usually done monthly by an employee of the local Dairy Herd Improvement Association.
In 1911, the American Dairy Science Association's Committee on Official Methods of Testing Milk and Cream for Butterfat, chaired by O. F. Hunziker, met in Washington DC with the Dairy Division of the USDA, the U.S. Bureau of Standards and manufacturers of glassware.As a result of those talks, the procedure and the special glassware were standardized by the US government in 1917. Additional specifications were published by the Association of Official Agricultural Chemists (now AOAC International) in 1927.
The test is based on the observation that a suitable amount of sulfuric acid added to the milk will dissolve proteins and other components, except the fat. Heating and centrifuging cause the fat to separate and float to the top, in a layer free of bubbles. The amount of fat in the milk can then be estimated from the volume of that layer. The procedure was commonly carried out in a special flask with a long neck, called a Babcock bottle.
Specifically, the test consisted of the following steps:
The scale on the neck was calibrated so as to give a direct readout of the percentage of fat in the original sample (assumed to be 17.6 mL), in 0.1 percent increments, without the need for computation.
The original Babcock test was not suitable for estimating the fat contents of ice cream, since the sugar and other ingredients would be charred by the sulfuric acid and contaminate the fat layer. After thousands of experiments, a modified test, suitable for the purpose, was developed in 1930 by L. K. Crowe at the University of Nebraska. It used a solution of ammonium hydroxide in N-butyl alcohol, and a mixture of sulfuric acid and ethanol.
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Cream is a dairy product composed of the higher-fat layer skimmed from the top of milk before homogenization. In un-homogenized milk, the fat, which is less dense, eventually rises to the top. In the industrial production of cream, this process is accelerated by using centrifuges called "separators". In many countries, it is sold in several grades depending on the total butterfat content. It can be dried to a powder for shipment to distant markets, and contains high levels of saturated fat.
Milk is a nutrient-rich liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals, including breastfed human infants before they are able to digest solid food. Early-lactation milk is called colostrum, which contains antibodies that strengthen the immune system and thus reduces the risk of many diseases. It holds many other nutrients, including protein and lactose. Interspecies consumption of milk is not uncommon, particularly among humans, many of whom consume the milk of other mammals.
Butter is a dairy product made from the fat and protein components of milk or cream. It is a semi-solid emulsion at room temperature, consisting of approximately 80% butterfat. It is used at room temperature as a spread, melted as a condiment, and used as an ingredient in baking, sauce making, pan frying, and other cooking procedures.
Buttermilk is a fermented dairy drink. Traditionally, it was the liquid left behind after churning butter out of cultured cream; however, most modern buttermilk is cultured. It is common in warm climates where unrefrigerated fresh milk sours quickly.
Decantation is a process for the separation of mixtures of immiscible liquids or of a liquid and a solid mixture such as a suspension. The layer closer to the top of the container—the less dense of the two liquids, or the liquid from which the precipitate or sediment has settled out—is poured off, leaving the other component or the more dense liquid of the mixture behind. An incomplete separation is witnessed during the separation of two immiscible liquids.To put it in a simple way decantation is separating an immiscible solution by transferring the top layer of the solution to another container.
Blue cheese or bleu cheese is cheese made with cultures of the mold Penicillium, giving it spots or veins of the mold throughout the cheese, which can vary in color through various shades of blue and green. This carries a distinct smell, either from that or various specially cultivated bacteria. Some blue cheeses are injected with spores before the curds form, and others have spores mixed in with the curds after they form. Blue cheeses are typically aged in a temperature-controlled environment such as a cave. Blue cheese can be eaten by itself or can be spread, crumbled or melted into or over a range of other foods. Blue cheese is known for its pungent creamy texture.
Dairy cattle are cattle cows bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cows generally are of the species Bos taurus.
The Brown Swiss or American Brown Swiss is an American breed of dairy cattle. It derives from the traditional triple-purpose Braunvieh of the Alpine region of Europe, but has diverged substantially from it. It was selectively bred for dairy qualities only, and its draft and beef capabilities were lost. Milk yield was measured in 2013 at 10231 kg (22600 lb) per year; the milk has about 4% butterfat and 3.5% protein and is suitable for making cheese.
Stephen Moulton Babcock was an American agricultural chemist. He is best known for his Babcock test in determining dairy butterfat in milk processing, for cheese processing, and for the "single-grain experiment" that led to the development of nutritional science as a recognized discipline.
Crème fraîche is a dairy product, a soured cream containing 10–45% butterfat, with a pH of approximately 4.5. It is soured with a bacterial culture. European labeling regulations specify the two ingredients must be cream and bacterial culture. It is served over fruit and baked goods, as well as being added to soups and sauces. It is used in a variety of other recipes. Sour cream is a similar foodstuff, except that crème fraîche is less sour and has a higher fat content. Sour cream may contain thickening agents not permitted in crème fraîche in many jurisdictions.
The American Dairy Science Association (ADSA) is a non-profit professional organization for the advancement of dairy science. ADSA is headquartered in Champaign, Illinois.
Κ-casein, or kappa casein, is a mammalian milk protein involved in several important physiological processes. In the gut, the ingested protein is split into an insoluble peptide and a soluble hydrophilic glycopeptide (caseinomacropeptide). Caseinomacropeptide is responsible for increased efficiency of digestion, prevention of neonate hypersensitivity to ingested proteins, and inhibition of gastric pathogens.
Otto Frederick Hunziker was a pioneer in the American and international dairy industry, as both an educator and a technical innovator. Hunziker was born and raised in Switzerland, emigrated to the U.S., and studied at Cornell University. He started and developed the dairy program at Purdue University when such programs were at their infancy. At this same time, Hunziker was heavily involved with the development of the American Dairy Science Association (ADSA) and the standardization and improvement of many dairy tests and processes. Hunziker wrote several of the leading dairy processing texts, which continue to be cited. After leaving Purdue University, Hunziker managed research and operations at a large, national condensary, continued to drive ADSA's standardization and publishing efforts, represented the U.S. at international dairy congresses, and facilitated dairy industry improvements across the globe.
The fat content of milk is the proportion of milk, by weight, made up by butterfat. The fat content, particularly of cow's milk, is modified to make a variety of products. The fat content of milk is usually stated on the container, and the color of the label or milk bottle top varied to enable quick recognition.
The Gerber method is a primary and historic chemical test to determine the fat content of substances, most commonly milk and cream. The Gerber method is the primary testing method in Europe and much of the world. The fairly similar Babcock test is used primarily in the United States, although the Gerber method also enjoys significant use in the U.S. as well.
Lore Alford Rogers was an American bacteriologist and dairy scientist. He is credited with discovering that butter made from pasteurized sweet cream remained fresher than that made from sour ripened cream, while suggesting that surplus milk could still be sold as concentrated sour milk products. He refined the steps for manufacture of high quality Swiss cheese and, new to the United States, production of Roquefort cheese. He was instrumental in finding ways to discourage fungal growth in sweetened condensed milk and preventing losses in evaporated milk from heat coagulation.
Sour cream or soured cream is a dairy product obtained by fermenting regular cream with certain kinds of lactic acid bacteria. The bacterial culture, which is introduced either deliberately or naturally, sours and thickens the cream. Its name comes from the production of lactic acid by bacterial fermentation, which is called souring. Crème fraîche is one type of sour cream with a high fat content and less sour taste.
A test tube brush or spout brush is a brush used for cleaning test tubes and narrow mouth laboratory glassware, such as graduated cylinders, burettes, and Erlenmeyer flasks. It is composed of nylon, synthetic, or animal fur bristles of various diameters lined against a rather sturdy wire handle with a looped end for hanging. The wire can be made from a wide range of metals, such as aluminium, bronze, beryllium, copper, and brass. FDA grade brushes are designed to be resistant to acid and other corrosive chemicals, including aromatic and aliphatic hydrocarbons, ketones, ethyl acetate esters,and trichloroethylene.
A Babcock bottle is a clear glass flask with a long graduated neck, used in the Babcock test to evaluate the cream contents of milk. It is also called a Babcock milk test bottle, milk test bottle, cream test bottle, and other similar names.
Louis Firth Nafis was an American entrepreneur and inventor, best known as the first manufacturer of the standard Babcock milk test bottle. He was born in Jersey City, New Jersey on November 1, 1884, and died on February 26, 1955, in Evanston, Illinois.