Dextrose crystallizes as the hydrate, CCH12O6.H2O, that is, one mole-
cule of water is combined with the molecule of dextrose. When heated
slowly it loses this water of crystallization between 50° and 60°C. Perkin
and Kipping state that the melting point of the hydrate is 86°, and that of
the anhydrous form is 146°C.
The melting point of levulose is 95 °C.
Solutions
Sugar and other substances are used constantly in cookery processes.
Therefore, it is desirable to know something about the properties of solu-
tions.
A solution is composed of two parts: one, the solute, is the dissolved
substance; and the other, the solvent, is the substance in which the solute
40 SUGAR COOKERY
is dissolved. A solution is a homogeneous mixture. This means that it is
uniformly mixed or alike in all parts.
A solution may be a gas dissolved in a solid, a gas in metal; a gas in a
liquid, air in water; a liquid in a liquid, alcohol in water; or a solid in
a liquid, sugar in water. It is to the class of solids in liquids that many
of our solutions in cookery belong.
Solubility of Substances in Solution
Solubility means the amount of a specific substance that will dissolve
in a given volume of a specified solvent. If the solvent is not mentioned
it is understood to be water. Solubility is generally expressed as the number
of grams of solute that will dissolve in 100 cc. of solvent, and as the tem-
perature affects solubility it is usually mentioned. If the temperature is not
stated it is understood to be room temperature or 20° to 22°C.
Factors determining the solubility. Temperature, the fineness of
division and the nature of the solute, and the nature of the solvent deter-
mine the solubility to a great extent. Some substances are highly, others
only slightly, soluble in water, and still others are highly insoluble in this
solvent. Some substances will dissolve best in alcohol, or chloroform, or
ether, or benzine. Some liquids, like alcohol and water, will dissolve in all
proportions, but there is a limit to the solubility of all substances of a
crystalline form.
Fineness of division of the solute. A larger amount of the crystal-
line solute is soluble if it is very finely divided or powdered than if left
in large crystals. This does not refer to the ease or quickness of solution
but to the total number of grams dissolved in 100 cc. of the solvent. This
increase in solubility is due to the increased surface energy of the smaller
particles in the solvent. The diameter of the particles must be less than 1/x
to increase the solubility to any great extent.
Temperature. The solubility of most crystalline substances in w^ater
is increased by heating, though some are little affected by temperature
change, and a few are less soluble in hot water than in cold. Sodium
chloride, common salt, is an example of a substance that is little affected
by temperature change. At 0°C. about 35.6 grams will dissolve in 100 cc.
of water, and about 39 grams at 100°. Calcium hydroxide is only half as
soluble at 100° as at 20°. The solubility of the sugars is increased by
elevation of temperature. At 0°C., 179 grams of sucrose will dissolve; at
100°C. 487 grams will dissolve.
Page 36
Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
A modernized reading is not available for this page yet. You are seeing the original text.
Dextrose crystallizes as the hydrate, CCH12O6.H2O, that is, one mole-
cule of water is combined with the molecule of dextrose. When heated
slowly it loses this water of crystallization between 50° and 60°C. Perkin
and Kipping state that the melting point of the hydrate is 86°, and that of
the anhydrous form is 146°C.
The melting point of levulose is 95 °C.
Solutions
Sugar and other substances are used constantly in cookery processes.
Therefore, it is desirable to know something about the properties of solu-
tions.
A solution is composed of two parts: one, the solute, is the dissolved
substance; and the other, the solvent, is the substance in which the solute
40 SUGAR COOKERY
is dissolved. A solution is a homogeneous mixture. This means that it is
uniformly mixed or alike in all parts.
A solution may be a gas dissolved in a solid, a gas in metal; a gas in a
liquid, air in water; a liquid in a liquid, alcohol in water; or a solid in
a liquid, sugar in water. It is to the class of solids in liquids that many
of our solutions in cookery belong.
Solubility of Substances in Solution
Solubility means the amount of a specific substance that will dissolve
in a given volume of a specified solvent. If the solvent is not mentioned
it is understood to be water. Solubility is generally expressed as the number
of grams of solute that will dissolve in 100 cc. of solvent, and as the tem-
perature affects solubility it is usually mentioned. If the temperature is not
stated it is understood to be room temperature or 20° to 22°C.
Factors determining the solubility. Temperature, the fineness of
division and the nature of the solute, and the nature of the solvent deter-
mine the solubility to a great extent. Some substances are highly, others
only slightly, soluble in water, and still others are highly insoluble in this
solvent. Some substances will dissolve best in alcohol, or chloroform, or
ether, or benzine. Some liquids, like alcohol and water, will dissolve in all
proportions, but there is a limit to the solubility of all substances of a
crystalline form.
Fineness of division of the solute. A larger amount of the crystal-
line solute is soluble if it is very finely divided or powdered than if left
in large crystals. This does not refer to the ease or quickness of solution
but to the total number of grams dissolved in 100 cc. of the solvent. This
increase in solubility is due to the increased surface energy of the smaller
particles in the solvent. The diameter of the particles must be less than 1/x
to increase the solubility to any great extent.
Temperature. The solubility of most crystalline substances in w^ater
is increased by heating, though some are little affected by temperature
change, and a few are less soluble in hot water than in cold. Sodium
chloride, common salt, is an example of a substance that is little affected
by temperature change. At 0°C. about 35.6 grams will dissolve in 100 cc.
of water, and about 39 grams at 100°. Calcium hydroxide is only half as
soluble at 100° as at 20°. The solubility of the sugars is increased by
elevation of temperature. At 0°C., 179 grams of sucrose will dissolve; at
100°C. 487 grams will dissolve.