basics of dietary fibre, classification and health benefits

1. Dietary fibre
Presented by
Remya.P.R
2016-24-001
1st PhD Homescience
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2. Definition
 The term was coined by Hipsley in 1953
 Dietary fiber is the edible parts of plants or analogous carbohydrates that are
resistant to digestion and absorption in the human small intestine with complete or
partial fermentation in the large intestine. Dietary fiber includes polysaccharides,
oligosaccharides, lignin, and associated plant substances. Dietary fibers promote
beneficial physiological effects including laxation, and/or blood cholesterol
attenuation, and/or blood glucose attenuation (AACC annual meeting).”
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3. classification
Soluble
fibre
Dietary
fibre
Insoluble
fibre
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4. Soluble fibre
 Soluble fiber attracts water and turns to gel
during digestion.
 This slows digestion.
 Some types of soluble fiber may help lower
risk of heart disease.
 Soluble fiber is found in oat bran, barley, nuts,
seeds, beans, lentils, peas, and some fruits
and vegetables. It is also found in psyllium, a
common fiber supplement.
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5. Insoluble fibre
 Insoluble fiber is found in foods such as wheat
bran, vegetables, and whole grains.
 It adds bulk to the stool and appears to help
food pass more quickly through the stomach
and intestines.
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6. composition
 The major components are
 Hemicellulose
 Cellulose
 Lignin
 Pectin
 Non structural polysacharides ( gums, waxes, cutin )
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7. Hemicellulose and cellulose
Hemicellulose
 Present along with cellulose in almost
all plant cell walls.
 Hemicellulose has a random,
amorphous structure with little
strength. It is easily hydrolyzed by
dilute acid or base as well as myriad
hemicellulase enzymes.
Cellulose
 Cellulose is an important structural
component of the primary cell wall of
green plants.
 Cellulose is the most abundant
organic polymer on Earth.
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8. Dietary fibre components and their
sources
cellulose
• Whole wheat
flour
• Brans
• Cabbage family
• Apple
• Root vegetables
Hemi cellulose
• Brans
• Cereals
• Whole grains
Gums
• Oat meal
• Dried bean
• Other lugumes
Lignin
• Wheat
• Mature
vegetables
Pectin
• Apple
• Citrus fruits
• Straw berry
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9. Physico-chemical properties
Dilute acid
• cellulose
Dilute alkali
• Cellulose
• Hemi cellulose
• Lignin
Water
• Cellulose
• Pectin
• Gums
Solubility
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10. Water holding capacity
 Water holding capacity is generally influenced by
 chemical composition,
 physical structure and
 particle size
 It is highest for wheat bran
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11. Binding of bile salts
 Prevents re absorption of bile salts in intestine
 Reduced blood cholesterol
 Lignin show strong binding property
 Rice bran have strong bile salt affinity
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12. Viscosity
 Water soluble dietary fibre contributes to viscosity
 Added to foods as thickners
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13. Physiological effects
 Increased faecal bulk
 Barrier to digestion
 Faecal transit
 Fermentability
 Reduced glycemic response
 Hypocholesterolemic effect
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14. Nutritional and
health implications
• Cardio vascular
diseases
• Diabetes mellitus
• Obesity
• Colon cancer
• Constipation
• Diverticular disease
• Gall stones
• Dermatological
disorders
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15. Gall stones
• Gallstones are small
stones, usually made of
cholesterol, that form in
the gallbladder.
• Also called cholelithiasis
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16. Diverticular disease
• Affects the large intestine
• small bulges or pockets
(diverticula) develop in the
lining of the intestine
• Symptoms of diverticular
disease include:
lower abdominal pain
feeling bloated
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17. Harmful effects of fibre
 Abdominal pain and increased flatulence
 Decreased absorption of minerals
 Fluid imbalance
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18. Food sources
Natural
Processed
Fibre concentrates
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19. Natural sources19
Cereals
 Pulses
 Leafy vegetables
 Roots and tubers
 Other vegetables
 Nuts and oil seeds
 Fruits

20. Processed foods
 Processing brings about change in the particle size of fibre
 Water holding capacity also get reduced
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21. Fibre concentrates
 Concentrated forms containing very high TDF
 Supplement the regular diet with fibre
 Eg dehydrated fruit and vegetables
 Oat fibre
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22. Daily needs
 30g/day or 12g/1000 kcal(Singh et al,2000)
 25-38g/day for diabetic (ADA,1994)
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23. Tips for increasing
dietary fibre
Eat a wholegrain cereal
in the morning.
Switch from white to
wholemeal bread.
Serve a side salad
Eat porridge with a
handful of dried fruit.
Add beans and pulses
to the regular diet
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24. conclusion
 Higher intake have beneficial effect on health
 Fibre is an essential component of healthy diet
 Eat more fibre for positive health
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