関: anhydrous lactose、milk sugar

WordNet

a sugar comprising one glucose molecule linked to a galactose molecule; occurs only in milk; "cows milk contains about 4.7% lactose" (同)milk_sugar

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/10/29 00:25:09」(JST)

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Lactose is a disaccharide sugar derived from galactose and glucose that is found in milk. Lactose makes up around 0~8% of milk (by weight), although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from lac or lactis, the Latin word for milk, plus the -ose ending used to name sugars. It has a formula of C₁₂H₂₂O₁₁.

History[edit]

Lactose was discovered in milk in 1619 by Fabrizio Bartoletti, and identified as a sugar in 1780 by Carl Wilhelm Scheele.^[3]

Structure and reactions[edit]

The molecular structure of α-lactose, as determined by X-ray crystallography.

Lactose is a disaccharide derived from the condensation of galactose and glucose, which form a β-1→4 glycosidic linkage. Its systematic name is β-D-galactopyranosyl-(1→4)-D-glucose. The glucose can be in either the α-pyranose form or the β-pyranose form, whereas the galactose can only have the β-pyranose form: hence α-lactose and β-lactose refer to anomeric form of the glucopyranose ring alone.

Lactose is hydrolysed to glucose and galactose, isomerised in alkaline solution to lactulose, and catalytically hydrogenated to the corresponding polyhydric alcohol, lactitol.^[3]

Lactose monohydrate crystals have a characteristic tomahawk shape that can be observed with a light microscope.

Isolation[edit]

Several million tons are produced annually as a by-product of the dairy industry. Whey is made of up 6.5% solids of which 4.8% is lactose that may be purified by crystallisation.^[4] Whey or milk plasma is the liquid remaining after milk is curdled and strained, for example in the production of cheese. Lactose makes up about 2-8% of milk by weight. Lactose is purified from whey by adding ethanol. Since it is insoluble in ethanol, lactose precipitates in about 65% yield.^[5]

Metabolism[edit]

Main article: Lactose intolerance

Infant mammals nurse on their mothers to drink milk, which is rich in lactose. The intestinal villi secrete the enzyme called lactase (β-D-galactosidase) to digest it. This enzyme cleaves the lactose molecule into its two subunits, the simple sugars glucose and galactose, which can be absorbed. Since lactose occurs mostly in milk, in most mammals, the production of lactase gradually decreases with maturity due to a lack of constant consumption.

Many people with ancestry in Europe, West Asia, India, and parts of East Africa maintain lactase production into adulthood. In many of these areas, milk from mammals such as cattle, goats, and sheep is used as a large source of food. Hence, it was in these regions that genes for lifelong lactase production first evolved. The genes of adult lactose tolerance have evolved independently in various ethnic groups.^[6] By descent, more than 70% of western Europeans can drink milk as adults, compared with less than 30% of people from areas of Africa, eastern and south-eastern Asia and Oceania.^[7] In people who are lactose intolerant, lactose is not broken down and provides food for gas-producing gut flora, which can lead to diarrhea, bloating, flatulence, and other gastrointestinal symptoms.

Applications[edit]

Food industry applications, both of pure lactose and lactose-containing dairy by-products, have markedly increased since the 1960s. For example, its bland flavor has lent to its use as a carrier and stabiliser of aromas and pharmaceutical products. Lactose is not added directly to many foods, because its solubility is less than other sugars commonly used in food. Infant formula is a notable exception, where the addition of lactose is necessary to match the composition of human milk.

Lactose is not fermented by yeast during brewing, which may be used to advantage.^[3] For example, lactose may be used to sweeten stout beer; the resulting beer is usually called a milk stout or a cream stout.

Another major use of lactose is in the pharmaceutical industry. Lactose is added to pills as a filler because of its physical properties (i.e., compressibility) and low price. For similar reasons it can be used to dilute heroin.

References[edit]

^ ^a ^b ^c Sigma Aldrich
^ The solubility of lactose in water is 18.9049 g at 25 °C, 25.1484 g at 40 °C and 37.2149 g at 60 °C per 100 g solution. Its solubility in ethanol is 0.0111 g at 40 °C and 0.0270 g at 60 °C per 100 g solution.Machado, José J. B.; Coutinho, João A.; Macedo, Eugénia A. (2001), "Solid–liquid equilibrium of α-lactose in ethanol/water", Fluid Phase Equilibria 173 (1): 121–34, doi:10.1016/S0378-3812(00)00388-5 . ds
^ ^a ^b ^c Linko, P (1982), "Lactose and Lactitol", in Birch, G.G. & Parker, K.J, Natural Sweeteners, London & New Jersey: Applied Science Publishers, pp. 109–132, ISBN 0-85334-997-5
^ Ranken, M. D.; R. C. Kill (1997), Food industries manual, Springer, p. 125, ISBN 0-7514-0404-7
^ Minard, R. Introduction to Organic Laboratory Techniques: A Microscale Approach. Pavia, Lampman, Kriz & Engel, Saunders. 1990.
^ Wade, Nicholas (2006-12-10), "Study Detects Recent Instance of Human Evolution", New York Times .
^ Ridley, Matt (1999), Genome, HarperCollins, p. 193, ISBN 978-0-06-089408-5 .

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English Journal

A study of different indicators of Maillard reaction with whey proteins and different carbohydrates under adverse storage conditions.

Leiva GE1, Naranjo GB1, Malec LS2.
Food chemistry.Food Chem.2017 Jan 15;215:410-6. doi: 10.1016/j.foodchem.2016.08.003. Epub 2016 Aug 3.
This study examined different indicators of each stage of Maillard reaction under adverse storage conditions in a system with whey proteins and lactose or glucose. The analysis of lysine loss by the o-phthaldialdehyde method can be considered a good indicator of the early stage, showing considerable
PMID 27542493

Cheese whey protein recovery by ultrafiltration through transglutaminase (TG) catalysis whey protein cross-linking.

Wen-Qiong W1, Lan-Wei Z2, Xue H3, Yi L4.
Food chemistry.Food Chem.2017 Jan 15;215:31-40. doi: 10.1016/j.foodchem.2016.07.057. Epub 2016 Jul 11.
In whey ultrafiltration (UF) production, two main problems are whey protein recovery and membrane fouling. In this study, membrane coupling protein transglutaminase (TG) catalysis protein cross-linking was investigated under different conditions to find out the best treatment. We found that the opti
PMID 27542447

Yeast surface display of dehydrogenases in microbial fuel-cells.

Gal I1, Schlesinger O1, Amir L1, Alfonta L2.
Bioelectrochemistry (Amsterdam, Netherlands).Bioelectrochemistry.2016 Dec;112:53-60. doi: 10.1016/j.bioelechem.2016.07.006. Epub 2016 Jul 19.
Two dehydrogenases, cellobiose dehydrogenase from Corynascus thermophilus and pyranose dehydrogenase from Agaricus meleagris, were displayed for the first time on the surface of Saccharomyces cerevisiae using the yeast surface display system. Surface displayed dehydrogenases were used in a microbial
PMID 27459246

Acute effects of caffeine on choroidal thickness and ocular pulse amplitude.

Dervişoğulları MS1, Totan Y2, Yüce A2, Kulak AE2.
Cutaneous and ocular toxicology.Cutan Ocul Toxicol.2016 Dec;35(4):281-6. doi: 10.3109/15569527.2015.1104330. Epub 2015 Nov 10.
OBJECTIVE: To explore ocular changes in healthy people after caffeine consumption.METHODS: This prospective observational study was carried out with students of the Turgut Özal University Medical Faculty from May 15 to 15 December 2014. Enrolled in the study were 17 healthy subjects (n = 17 eye
PMID 26555634

Japanese Journal

Preparation of Fine Particles with Improved Solubility Using a Complex Fluidized-Bed Granulator Equipped with a Particle-Sizing Mechanism

Chemical and Pharmaceutical Bulletin 64(6), 644-649, 2016
NAID 130005154413

Analysis of the breast milk of giant pandas (Ailuropoda melanoleuca) and the preparation of substitutes

Journal of Veterinary Medical Science 78(5), 747-754, 2016
NAID 130005154289

食品用途に利用可能な機能性糖質ラクトビオン酸の生産法の開発

日本食品科学工学会誌 63(4), 137-141, 2016
NAID 130005154273

A Novel Method of Antibacterial Evaluation Based on the Inhibition of Hydrogen Sulfide Producing Activities of Salmonella:–Using Copper as a Model Antibacterial Agent–

MATERIALS TRANSACTIONS 57(6), 995-1000, 2016
NAID 130005153141

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★リンクテーブル★

リンク元	「乳糖」「ラクトース」「anhydrous lactose」
拡張検索	「galactose microparticle」「galactosemia」「lactose tolerance test」
関連記事	「lacto」

「乳糖」

Lactose (Milk sugar)
	IUPAC name β-D-galactopyranosyl-(1→4)-D-glucose
	Other names Milk sugar; 4-O-β-D-galactopyranosyl-D-glucose
Identifiers
CAS number	63-42-3Template:Ca÷scite
PubChem	6134←←
ChemSpider	5904
UNII	J2B2A4N98G
EC-number	200-559-2
ChEBI	CHEBI:36218
ChEMBL	CHEMBL417016
Jmol-3D images	Image 1
	SMILES C([C@@H]1[C@@H]([C@@H]([C@H]([C@@H](O1)O[C@@H]2[C@H](O[C@H]([C@@H]([C@H]2O)O)O)CO)O)O)O)O ;
	InChI InChI=1S/C12H22O11/c13-1-3-5(15)6(16)9(19)12(22-3)23-10-4(2-14)21-11(20)8(18)7(10)17/h3-20H,1-2H2/t3-,4-,5+,6+,7-,8-,9-,10-,11-,12+/m1/s1 ; Key: GUBGYTABKSRVRQ-DCSYEGIMSA-N InChI=1/C12H22O11/c13-1-3-5(15)6(16)9(19)12(22-3)23-10-4(2-14)21-11(20)8(18)7(10)17/h3-20H,1-2H2/t3-,4-,5+,6+,7-,8-,9-,10-,11-,12+/m1/s1; Key: GUBGYTABKSRVRQ-DCSYEGIMBP ;
Properties
Molecular formula	C12H22O11
Molar mass	342.30 g/mol
Appearance	white solid
Density	1.525 g/cm3
Melting point	202.8 °C
Boiling point	668.9 °C
Solubility in water	21.6 g/100 mL
Thermochemistry
Std enthalpy of; combustion ΔcHo298	5652 kJ/mol, 1351 kcal/mol, 16.5 kJ/g, 3.94 kcal/g
Hazards
EU Index	not listed
NFPA 704	0 1 0
Flash point	357.8 °C
	(verify) (what is: /?); Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
	Infobox references

　　[★]

英: lactose, milk sugar
同: ラクトース
関: 二糖類

「ラクトース」

　　[★]

英: lactose
同: 乳糖 milk sugar
関: 二糖

「anhydrous lactose」

　　[★]

無水ラクトース、無水乳糖

関: lactose

「galactose microparticle」

　　[★]

ガラクトース微粒子

「galactosemia」

　　[★] ガラクトース血症　

「lactose tolerance test」

　　[★]

ラクトース負荷試験

「lacto」

　　[★]

ラクト、乳

関: milk

[Ald-1] Sigma Aldrich

[2] The solubility of lactose in water is 18.9049 g at 25 °C, 25.1484 g at 40 °C and 37.2149 g at 60 °C per 100 g solution. Its solubility in ethanol is 0.0111 g at 40 °C and 0.0270 g at 60 °C per 100 g solution.Machado, José J. B.; Coutinho, João A.; Macedo, Eugénia A. (2001), "Solid–liquid equilibrium of α-lactose in ethanol/water", Fluid Phase Equilibria 173 (1): 121–34, doi:10.1016/S0378-3812(00)00388-5 . ds

[Linko1981-3] Linko, P (1982), "Lactose and Lactitol", in Birch, G.G. & Parker, K.J, Natural Sweeteners, London & New Jersey: Applied Science Publishers, pp. 109–132, ISBN 0-85334-997-5

[4] Ranken, M. D.; R. C. Kill (1997), Food industries manual, Springer, p. 125, ISBN 0-7514-0404-7

[5] Minard, R. Introduction to Organic Laboratory Techniques: A Microscale Approach. Pavia, Lampman, Kriz & Engel, Saunders. 1990.

[6] Wade, Nicholas (2006-12-10), "Study Detects Recent Instance of Human Evolution", New York Times .

[7] Ridley, Matt (1999), Genome, HarperCollins, p. 193, ISBN 978-0-06-089408-5 .

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案内

案内

lactose