Products Description

Molecular formula: C12H22O11
Category: Disaccharide
Found in mammalian milk
Molecular weight: 342.3
Appearance: White crystals or crystalline powder
Water solubility: 0.216 g/mL
CAS number: 63-42-3
EINECS number: 200-559-2
Melting point: 222.8 ℃
Boiling point: 667.9 ℃
Flash point: 357.8 ℃

Lactose is a disaccharide formed by the β-1,4 linkage of D-glucose and D-galactose, also known as 1,4-galactosyl glucose, and it is a reducing sugar. When crystallized from an aqueous solution, it carries one molecule of crystallization water.
It is a white to off-white crystalline particle or powder, with a sweetness of approximately 70% of sucrose, a specific gravity of 1.525 at 20°C, and loses crystallization water at 120°C. The anhydrous form has a melting point of 222.8°C. This substance is easily soluble in water, insoluble in ethanol, trichloromethane, or ether. It has reducing properties and dextrorotatory optical activity. It can be hydrolyzed into equal-molecular-weight glucose and galactose.
The solubility of α-lactose and β-lactose in water also varies with temperature. When α-lactose dissolves in water, it gradually transforms into the β form. Because β-lactose is more soluble in water than α-lactose, the initial solubility of lactose is not stable but gradually increases until an equilibrium between the α and β forms is reached. Sweetened condensed milk contains most of its lactose in a crystalline state. The size of the crystals directly affects the taste of the condensed milk, and the size of the crystals can be controlled based on the relationship between the solubility of lactose and temperature.

Items	Specifications	Analysis results
Appearance	White crystalline granule or powder, odorless, tastes sweet.	Meet the requirement.
Solubility	Soluble in water, but insoluble in ethanol, chloroform and ethyl ether.	Meet the requirement.
Special rotation	+52.3°～+52.6°	+52.3°
Moisture (%)	4.5～5.5	5.0
Content (%)	98.0～102.0	99.7
Residue ignition (%)	≦1.0	0.03
Loss on drying (%)	≦1.0	0.11
Heavy metal	≦5ppm	Meet the requirement
Arsenic (%)	0.0002	Meet the requirement
pH	4.0～7.0	4.8
Bacteria count	≦1000/g	﹤10/g
Mould count	≦100/g	﹤10/g
Escherichia coli	Cannot be detected	Meet the requirement

Products Application

It is used for making infant food, candies, artificial butter, etc. In medicine, it is used as an odor corrector and can be obtained by extracting from whey.
α-Lactose hydrate is widely used in pharmaceutical production. It is used as a filler, flow aid, disintegrant, lubricant and binder in solid preparations, and as a formulation agent in freeze-dried preparations. It is included in many national pharmacopoeias.

Lactose, like other sugars, is a source of energy for the human body. One quarter of the total calories in milk come from lactose.
Apart from providing energy for the human body, lactose also has physiological significance that is different from other sugars. Lactose is not digested or absorbed in the human stomach and can directly reach the intestines. In the human intestines, lactose is easily decomposed by lactase into glucose and galactose, which can be absorbed. Galactose is a component of glycolipids that constitute the brain and nerve tissues, and is very important for the intellectual development of infants. It can promote the formation of galactosyl cerebrosides and mucopolysaccharides. Lactose can promote the generation of certain lactobacilli in the human intestinal tract, inhibit the growth of putrefactive bacteria, and help with intestinal peristalsis. Since the production of lactic acid is conducive to the absorption of calcium and other substances, it can prevent rickets. Infant foods often contain fortified lactose.