Today is our topic of discussion Carbohydrate Food
Carbohydrate Food
Definition:
Any of a large group of organic compounds occurring in foods and living tissues. including sugars, starch, and cellulose. Carbohydrates are derived from alcohol. Example – glucose. fructose, starch etc.
Sources of carbohydrate:
1. Sugars mono and disaccharides glucose, fructose (fruits), galactose, sucrose (sugar cane), lactose (milk), maltose (corn syrup, bread) etc.
2. Starch – cereals, roots, tuber, plant stems etc. bind Laviac
3. Cellulose – vegetable, cereals, fibrous lining of fruits.
Classification of carbohydrate:
According to number of sugar units in the molecule-
Monosaccharide (simple sugar) –
Those carbohydrates which cannot be further broken down. Example – glucose, fructose, galactose.
Disaccharide –
On broken down produces two units of monosaccharides. Example – sucrose (glucose + fructose), maltose (glucose + glucose), lactose (glucose + galactose).
Oligosaccharide –
Produces 3 to 10 units of monosaccharides when broken down.
Polysaccharide
Produces more than 10 units of monosaccharides when broken down. Example – starch (plant cell), glycogen (animal cell) and cellulose (plant cell wall).
Lactose:
Lactose is the sugar present in milk. It is a disaccharide and hydrolysed into glucose and galactose.
Maltose:
Maltose is a disaccharide made up of two molecules of glucose. It is formed by the breakdown of starch in the process of malting.
Fructose:
Fructose is a monosaccharide found in fruits and vegetables and mainly responsible for their sweetness.
Glucose:
Glucose is a monosaccharide found in fruits and vegetables, but is less sweet than fructose and sucrose. Honey is mainly a mixture of fructose and glucose.
Function of carbohydrate:
1. Ready source of energy.
2. It is one of the structural materials of cell membrane.
3. It forms an important storage form of food material.
4. It is the only source of nutrition to the nervous tissue and retina.
5. Glucose is converted to other carbohydrates having highly specific functions, such as glycogen for storage, ribose in nucleic acids (DNA & RNA) etc.
Requirement of carbohydrate:
About 55% of our daily calorie should come from carbohydrates.
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