Lactose-structure-properties-applications-benefits-disadvantages

LEARNING OBJECTIVES

In this article, author has explained about lactose sugar, structure of lactose, properties and applications of lactose.


Lactose is a disaccharide found in the mammary glands of all mammals. It is commonly known as “milk sugar”. It is very essential carbohydrate for infants. It is a common disaccharide of milk. When lactose is absorbed in the intestine, the enzyme “lactase” breaks it into glucose and galactose.

When lactase is absent it causes a disease called lactose intolerance.

Lactose is made up of two monosaccharides; glucose and galactose, both are building blocks of carbohydrates.

Structure of lactose

Lactose is made when β-D-glucose and β-D-galactose are linked through a glycosidic bond. The bond is formed between carbon 1 and carbon 4.

image showing structure of lactose sugar

As shown from the structure, the bond is a 1,4 glycosidic bond in beta orientation.

Properties of structure

  • The chemical formula of lactose is C12H22O11.
  • Lactose has a crystalline structure.
  • Lactose has free anomeric carbon, therefore, lactose shows reducing properties.
  • When lactose is absorbed in the small intestine, the enzyme lactase breaks it into glucose and galactose.
  • Lactose is less sweet as compared to sucrose.
  • Lactose has 4kcal/g energy.
  • The mass of lactose is 342.3g/mol.
  • It is water as well as alcohol soluble.
  • Its melting point is 202.80C.

Applications of lactose

  • Lactose is a “lactating agent”. It is a major nutrient of milk.
  • Present in the milk of all mammals.
  • Use in pharmaceuticals industries.
  • Use in aromas and flavoring agents.
  • Also, use in drug products.
  • Use in fermentation for the production of cheese, yogurt, and sour milk.
  • Use in baked items.
  • Use in many edibles like condensed milk, ice cream, meat products, chocolates, canned fruits, vegetables, etc.

Benefits of lactose

  • Lactose assists in the absorption of many other minerals like calcium, magnesium, and zinc.
  • Human breast milk contains lactose a major nutrient that is essential for the growth of babies.
  • It causes less tooth decay as compared to other sugars.
  • Lactose inhibits the growth of pathogenic bacteria.
  • Provides glucose which is a source of energy.

Disadvantages of lactose

  • Milk containing a high concentration of lactose is rich in fat and cholesterol which increases the risk of a heart attack.
  • People who are lactose intolerant are unable to digest lactose.
  • Milk rich in lactose can lead to breast and ovarian cancer.

Lactose milk is rich in saturated fats which can cause many diseases like Alzheimer’s disease, type 2 diabetes, and heart diseases.