Dietary Fibre.pdf

DIETARY FIBRE.
Is generally defined as lignin plus plant polysaccharides that cannot be digested by human enzymes.
importance of dietary fiber.
major components of dietary fiber.
categories of dietary fiber.
plant sources of fiber.
supplements of dietary fiber.

1. DIETARY FIBRE
PRESENTED BY,
JIKHILAMACHADO
1
ST
M. PHARM

2. DEFINITION
Dietary fibre is generally defined as lignin plus plant
polysaccharides that cannot be digested by human enzymes.
-Some starch is not digested In small intestine and therefore
fits the definition of dietary fibre.

3. IMPORTANCE OF DIETARY FIBRE
•Helps to protect against colon cancer and helps to normalize blood lipids thereby
reduce cardiovascular disease.
•Certain type, can slow glucose absorption and reduce insulin secretion →great
importance for diabetics
•Prevent constipation and diverticular disease.
•Is an essential component of a well balanced diet.
•Adequate intake helps to minimize some of the common health problems in the
United States.

4. MAJOR COMPONENTS OF DIETARY FIBRE
•Cellulose
•Hemicellulos
•Pectins
•Hydrocolloids
•Lignin

5. FIBERIS CATEGORIZED AS;
1.Cell wall polysaccharides
2.Non-cell wall polysaccharides
3.Lignin

6. CELL WALL POLYSACCHARIDES
a) cellulose
-Is a long, linear polymer of β-1, 4-linked glucose units
-contain 10000 glucose units
-Hydrogen bonding between parallel polymers form strong microfibrils→
provide strength and rigidity to cell walls
b) Hemicellulose
-Are heterogeneous groups of substances containing a number of sugars in their
backbone and side chains.

7. -Contain 50 to 100 sugar units.
-soluble in dilute alkali but not in water
-form covalent bonds with lignin.
c) Pectins
-Are rich in uronicacids
-Are soluble in hot water and form gels
-These are matrix polysaccharides in cell wall
-solubility reduced by methylation of free carboxyl group

8. NON-CELL WALL POLYSACCHARIDES
•Include hydrocolloids such as mucilages, gums, and algal polysaccharide
•-Hydrocolloids –Are hydrophilic polysaccharides that form viscous
solutions or dispersions in cold or hot water.
• Mucilages–Are guar and locust bean gums eg: Oats and barley.
• Gums -Include arabic, karayaand tragaccanthgums
•These contains neutaralsugars and uronicacids.

9. LIGNIN
•Is a non-carbohydrate
•Three dimensional polymer consisting of 40 phenol units with strong
intramolecular bonding.
•Often covalently linked to hemicellulose.

10. PLANT SOURCES OF FIBRE
•Soluble fibre →Legumes , apple,
bannana, plum,
carrot.
• Inolublefibre →whole grain foods,
nuts, seeds
kiwi, grapes

11. SUPPLEMENTS
1.Insulin
2.Vegetable gums

12. REFERENCES
•Introduction to the chemical analysis of foods , by S. Nielsen, Jones and Bartlett
publishers Page no;
•Text book of biochemistry, 4
th
edition , page no;
•Text of principles of anatomy and physiology, 13
th
edition, page no;

13. THANK YOU