lactosen.
/ˈlaktəʊz/, /ˈlaktəʊs/, U.S. /ˈlækˌtoʊs/, /ˈlækˌtoʊz/ Chemistry.
A sugar present in milk, and used in food processing and pharmaceutical manufacture. Also called milk sugar.Lactose is a disaccharide containing glucose and galactose units. Formula: C12H22O11.
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the world > food and drink > food > additive > sweetener > [noun] > sugar > lactose
sugar of milk1753
milk sugar1846
lactose1847
galactose1862
the world > matter > chemistry > organic chemistry > carbohydrates > sugars > oligosaccharides > [noun] > disaccharides > lactose
sugar of milk1753
lactose1847
galactin1885
1847 Med. Times 19 June 330/3 It [sc. milk] is constituted of a solution of casèine, lactose, and salts, in which float isolated and perfectly circular globules of fatty matter.
1866 H. E. Roscoe Lessons Elem. Chem. xxxvii. 325 Lactose, or milk sugar, occurs only in the milk of mammalia.
1910 Times 11 July 4/5 (advt.) Lion Brewery milk-stout..is brewed from the best malt and hops and lactose (sugar of milk).
1983 T. H. Grenby in T. H. Grenby et al. Devel. Sweeteners—2 iii. 62 The 15% sucrose in wheatmeal ‘digestive’ biscuits was replaced by a mixture of 5% maltose..and 1% each of lactose, glucose and maltotriose, together with saccharin for added sweetness.
2005 S. Holt Food for Life (2007) 13 Glucose and sucrose..have relatively high-GI values, whereas lactose (milk sugar) and fructose (fruit sugar) have low-GI values.
Compounds
lactose intolerance n. [after French intolérance au lactose (1960 or earlier)] a condition caused by deficiency of the enzyme lactase in the small intestine, with consequent malabsorption of lactose, often resulting in abdominal pain, bloating, and diarrhoea after ingestion of milk and other dairy products.Some degree of lactase deficiency is seen in most adult mammals, including many human populations other than those of northern and central European origin.
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1961 Lancet 12 Aug. 374/2 The test-result was positive in one case of lactose intolerance.
1993 T. McGinnis Well Cat Bk. (new ed.) 173 Oligosaccharide intolerance is similar to lactose intolerance, which occurs when a cat is unable to digest milk sugar (lactose) and bacteria in the gut ferment the excess carbohydrates causing gas production and sometimes diarrhea.
2017 Sunday Times (Nexis) 12 Nov. 3 Bad science and urban myths about dairy's fat levels, allergies and lactose intolerance are wrongly encouraging millennials to opt for trendy almond-milk lattes.
lactose-intolerant adj. and n. [after lactose intolerance n.] (a) adj. (of a person or animal) affected by lactose intolerance; (b) n. a lactose-intolerant individual; (with the and plural agreement) lactose-intolerant individuals as a class.
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1965 Lancet 20 Mar. 653/1 The lactase activity of our lactose-intolerant subjects is much lower than the reported normal values.
1971 Current Anthropol. 12 495 In this case, the lactose-tolerant are favored over the lactose-intolerant.
2001 Philadelphia Citypaper 15 Mar. 6/1 Now we've got Lactose-intolerants, Peanut-haters, Meat-mavens, Carb-loaders, Chicken but no Meat, Fish but no shellfish and on and on and on.
2016 M. L. Power & J. Schulkin Milk: Biol. of Lactation vi. 122 Adult mammals rarely express this enzyme [sc. lactase] and thus are lactose intolerant.
lactose-negative adj. Microbiology (of a bacterium) unable to metabolize lactose; (also) designating the condition of being unable to metabolize lactose.
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1914 Science 29 May 800/1 Of the dextrose positive lactose negative forms five liquefied gelatine and fermented dextrose and saccharose but failed to ferment any of the other sugars, with the exception of glycerine.
1951 Year Bk. (Carnegie Institution Washington) No. 50 187 Colonies obtained from such segregants should be composed..of lactose-negative mutants if the selected nucleus from which they arise happens to carry a second induced mutation, to the lactose-negative condition.
2009 R. E. Levin Rapid Detection & Characterization Foodborne Pathogens iii. 63 Members of the genus Shigella are facultatively anaerobic, gram-negative..nonmotile rods that are either lactose negative or ferment lactose slowly.
lactose operon n. Molecular Biology the part of a bacterial chromosome containing a sequence of genes responsible for the metabolism of lactose and other β-galactosides; = lac operon n. at lac n.3 Compounds 2.
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1961 F. Jacob & J. Monod Cold Spring Harbor Symp. Quantitative Biol. 26 205 (heading) Polarized effects of mutations at different loci on the lactose operon.
1985 Proc. National Acad. Sci. U.S.A. 82 6414/1 The DNA sequence of the control elements of the lactose operon was one of the first to be studied.
2009 D. P. Clark & N. J. Pazdernik Biotechnology ii. 41 (caption) The lactose operon is turned on only when glucose is absent but lactose is present.
lactose-positive adj. Microbiology (of a bacterium) able to metabolize lactose; (also) designating the condition of being able to metabolize lactose.
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1912 D. McKail Public Health Chem. & Bacteriol. xviii. 359 111 Lactose-positive streptococci were found in 156 c.c. of raw river water.
1956 C. Hinshelwood Addr. President p. x, in Proc. Royal Soc. A. 238 If, however, a very large inoculum of cells..is plated, some colonies develop much more rapidly, and their number has been used to give a measure of the so-called lactose-positive condition.
2009 R. E. Levin Rapid Detection & Characterization Foodborne Pathogens v. 142 This is due to the large number of sucrose-negative, lactose-positive vibrios in marine environments.
This entry has been updated (OED Third Edition, September 2018; most recently modified version published online March 2022).
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