The Collaborative International Dictionary of English v.0.48:
lactose \lac"tose`\ (l[a^]k"t[=o]s`), n.
1. (Physiol. Chem.) The main sugar present in milk, called
also sugar of milk or milk sugar. When isolated pure
it is obtained crystalline; it is separable from the whey
by evaporation and crystallization. It is a disaccharide
with the formula C12H22O11, being chemically
4-([beta]-D-galactosido)-D-glucose. It has a slightly
sweet taste, is dextrorotary, and is much less soluble in
water than either cane sugar or glucose. Formerly called
lactin. When hydrolyzed it yields glucose and galactose.
In cells it may be hydrolyzed by the enzyme
[beta]-galactosidase.
[1913 Webster +PJC]
2. (Chem.) See Galactose.
[1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Maltose \Malt"ose`\ (m[add]lt"[=o]s`), n. [From Malt.]
(Biochem.)
A crystalline disaccharide (C12H22O11) formed from starch
by the action of diastase of malt, and the amylolytic ferment
of saliva and pancreatic juice; called also maltobiose and
malt sugar. Chemically it is
4-O-[alpha]-D-glucopyranosyl-D-glucose. It rotates the plane
of polarized light further to the right than does dextrose
and possesses a lower cupric oxide reducing power.
[1913 Webster +PJC]
The Collaborative International Dictionary of English v.0.48:
Sugar \Sug"ar\, n. [OE. sugre, F. sucre (cf. It. zucchero, Sp.
az['u]car), fr. Ar. sukkar, assukkar, fr. Skr. [,c]arkar[=a]
sugar, gravel; cf. Per. shakar. Cf. Saccharine, Sucrose.]
1. A sweet white (or brownish yellow) crystalline substance,
of a sandy or granular consistency, obtained by
crystallizing the evaporated juice of certain plants, as
the sugar cane, sorghum, beet root, sugar maple, etc. It
is used for seasoning and preserving many kinds of food
and drink. Ordinary sugar is essentially sucrose. See the
Note below.
[1913 Webster]
Note: The term sugar includes several commercial grades, as
the white or refined, granulated, loaf or lump, and the
raw brown or muscovado. In a more general sense, it
includes several distinct chemical compounds, as the
glucoses, or grape sugars (including glucose proper,
dextrose, and levulose), and the sucroses, or true
sugars (as cane sugar). All sugars are carbohydrates.
See Carbohydrate. The glucoses, or grape sugars, are
ketone alcohols of the formula C6H12O6, and they turn
the plane of polarization to the right or the left.
They are produced from the amyloses and sucroses, as by
the action of heat and acids of ferments, and are
themselves decomposed by fermentation into alcohol and
carbon dioxide. The only sugar (called acrose) as yet
produced artificially belongs to this class. The
sucroses, or cane sugars, are doubled glucose
anhydrides of the formula C12H22O11. They are usually
not fermentable as such (cf. Sucrose), and they act
on polarized light.
[1913 Webster]
2. By extension, anything resembling sugar in taste or
appearance; as, sugar of lead (lead acetate), a poisonous
white crystalline substance having a sweet taste.
[1913 Webster]
3. Compliment or flattery used to disguise or render
acceptable something obnoxious; honeyed or soothing words.
[Colloq.]
[1913 Webster]
Acorn sugar. See Quercite.
Cane sugar, sugar made from the sugar cane; sucrose, or an
isomeric sugar. See Sucrose.
Diabetes sugar, or Diabetic sugar (Med. Chem.), a variety
of sugar (grape sugar or dextrose) excreted in the urine
in diabetes mellitus; -- the presence of such a sugar in
the urine is used to diagnose the illness.
Fruit sugar. See under Fruit, and Fructose.
Grape sugar, a sirupy or white crystalline sugar (dextrose
or glucose) found as a characteristic ingredient of ripe
grapes, and also produced from many other sources. See
Dextrose, and Glucose.
Invert sugar. See under Invert.
Malt sugar, a variety of sugar isomeric with sucrose, found
in malt. See Maltose.
Manna sugar, a substance found in manna, resembling, but
distinct from, the sugars. See Mannite.
Milk sugar, a variety of sugar characteristic of fresh
milk, and isomeric with sucrose. See Lactose.
Muscle sugar, a sweet white crystalline substance isomeric
with, and formerly regarded to, the glucoses. It is found
in the tissue of muscle, the heart, liver, etc. Called
also heart sugar. See Inosite.
Pine sugar. See Pinite.
Starch sugar (Com. Chem.), a variety of dextrose made by
the action of heat and acids on starch from corn,
potatoes, etc.; -- called also potato sugar, corn
sugar, and, inaccurately, invert sugar. See Dextrose,
and Glucose.
Sugar barek, one who refines sugar.
Sugar beet (Bot.), a variety of beet (Beta vulgaris) with
very large white roots, extensively grown, esp. in Europe,
for the sugar obtained from them.
Sugar berry (Bot.), the hackberry.
Sugar bird (Zool.), any one of several species of small
South American singing birds of the genera Coereba,
Dacnis, and allied genera belonging to the family
Coerebidae. They are allied to the honey eaters.
Sugar bush. See Sugar orchard.
Sugar camp, a place in or near a sugar orchard, where maple
sugar is made.
Sugar candian, sugar candy. [Obs.]
Sugar candy, sugar clarified and concreted or crystallized;
candy made from sugar.
Sugar cane (Bot.), a tall perennial grass (Saccharum
officinarium), with thick short-jointed stems. It has
been cultivated for ages as the principal source of sugar.
Sugar loaf.
(a) A loaf or mass of refined sugar, usually in the form
of a truncated cone.
(b) A hat shaped like a sugar loaf.
[1913 Webster]
Why, do not or know you, grannam, and that sugar
loaf? --J. Webster.
[1913 Webster]
Sugar maple (Bot.), the rock maple (Acer saccharinum).
See Maple.
Sugar mill, a machine for pressing out the juice of the
sugar cane, usually consisting of three or more rollers,
between which the cane is passed.
Sugar mite. (Zool.)
(a) A small mite (Tyroglyphus sacchari), often found in
great numbers in unrefined sugar.
(b) The lepisma.
Sugar of lead. See Sugar, 2, above.
Sugar of milk. See under Milk.
Sugar orchard, a collection of maple trees selected and
preserved for purpose of obtaining sugar from them; --
called also, sometimes, sugar bush. [U.S.] --Bartlett.
Sugar pine (Bot.), an immense coniferous tree (Pinus
Lambertiana) of California and Oregon, furnishing a soft
and easily worked timber. The resinous exudation from the
stumps, etc., has a sweetish taste, and has been used as a
substitute for sugar.
Sugar squirrel (Zool.), an Australian flying phalanger
(Belideus sciureus), having a long bushy tail and a
large parachute. It resembles a flying squirrel. See
Illust. under Phlanger.
Sugar tongs, small tongs, as of silver, used at table for
taking lumps of sugar from a sugar bowl.
Sugar tree. (Bot.) See Sugar maple, above.
[1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Sucrose \Su"crose`\, n. [F. sucre sugar. See Sugar.] (Chem.)
A common variety of sugar found in the juices of many plants,
as the sugar cane, sorghum, sugar maple, beet root, etc. It
is extracted as a sweet, white crystalline substance which is
valuable as a food product, and, being antiputrescent, is
largely used in the preservation of fruit. Called also
saccharose, cane sugar, etc. At one time the term was
used by extension, for any one of the class of isomeric
substances (as lactose, maltose, etc.) of which sucrose
proper is the type; however this usage is now archaic.
[1913 Webster +PJC]
Note: Sucrose proper is a dextrorotatory carbohydrate,
C12H22O11. It does not reduce Fehling's solution, and
though not directly fermentable, yet on standing with
yeast it is changed by the diastase present to invert
sugar (dextrose and levulose), which then breaks down
to alcohol and carbon dioxide. It is also decomposed to
invert sugar by heating with acids, whence it is also
called a disaccharate. Sucrose possesses at once the
properties of an alcohol and a ketone, and also forms
compounds (called sucrates) analogous to salts. Cf.
Sugar.
[1913 Webster]