Short note on Dietary fibres with examples

1. DIETARY FIBRES, CEREALS AND
GRAINS
By
V.K.VIKRAM VARMA
M PHARMACY
(PHARMACOGNOSY )
1yr
SPER
JAMIA HAMDARD

2. WHAT IS A DIETARY FIBER?
• Dietary fibre is a complex carbohydrate that is neither
digested nor absorbed in the small intestine.
• Non-nutrient
• Makes one feels fuller for a long time

3. HISTORY
• 430 BC: - Hippocrates described
laxative effects of coarse wheat in
comparison with refined wheat
• 1920s: - J.H Kellogg published
property of bran
• Dietary fibre researched
throughout the 1930s
• Term dietary fibre coined by
Hipsley (1953)
• Fibre became a common word
during 1970s
• Dr. Denis Burkitt (Fibre Man)
stated that fibre can prevent
certain diseases.

4. CLASSIFICATION

5.  INSOLUBLE DIETARY
FIBRE
• Insoluble fibre is
found in foods such
as wheat bran,
vegetables, and
whole grains.
• It adds bulk to the
stool & appear to
help food pass more
quickly through the
stomach and
intestine.
• Classification:
 Cellulose
 Hemicellulose
 Lignin

6. CELLULOSE
• Major cell wall component
• Soluble in concentrated acid
• Remains in digestive tract and act as bulk
• Help to move the food material ahead in
digestive tract
• Food Sources: - Vegetables, Sugar beet,
various bran

7. HEMICELLULOSE
• Cell wall
polysaccharides
• Soluble in dilute alkali
• Contain different sugar
monomers
• Mostly xylose and some
galactose, mannose,
arabinose and other
sugars.
• Branched and Smaller in
size
• Food Sources: - Cereal
grains

8. LIGNIN
• Not a polysaccharide
• Complex random polymer
• Contain phenylpropane units
including coniferyl, simply and p-
coumaryl alcohols
• Provide stiffness and rigidity
• Lignin → imp. Component of
DF → makes fibre hydrophobic
→ resistant to enzymatic
breakdown in small intestine and
bacterial breakdown in large
intestine
• Almost completely recovered in
faeces
• Food source: -Woody plants

9. NAME BIOLOGICAL
SOURCE
ACTIVE
CONSTITUENTS
USES FIBRE
CONTENT
APPLE Malus domestica Borkh
(Rosaceae)
catechin, epicatechin,
procyanidin, coumaric
acid, chlorogenic acid,
gallic acid, quercetin-3-
galactoside, quercetin-
3-glucoside.
Anti-cancer,
antioxidant, anti-
diabetic, anti-
inflammatory.
4.4 grams in a
medium-sized
apple, or 2.4
grams per 100
grams.
PINEAPPLE Ananas comosus
(Bromeliaceae)
Proteolytic
enzymes(Bromelain),
Citric and Malic acids
Anti-
inflammatory,
Treat Arthritis.
a 1-cup serving
of fresh
pineapple chunks
provides 2.3
grams of fiber
EXAMPLES

10. NAME BIOLOGICAL
SOURCE
ACTIVE
CONSTITUENTS
USES FIBRE
CONTENT
TOMATO Solanum lycopersicum
(Solanaceae)
beta-
carotene, flavonoids,
carotenoids, lycopene,
Quercetin,
polyphenols, kaempferol.
Anti-diabetic,
Anti-cancer.
2.4 grams per
cup, or 2.6 grams
per 100 grams.
BROCCOLI Brassica oleracea var
(Brassicaceae)
Indoles, iso thiocyanates,
indole-3-carbinol, s-
methyl cysteine sulfoxide.
Anticancer,
Antioxidant,
Cholesterol
reduction, Anti-
inflammatory.
2.4 grams per
cup, or 2.6 grams
per 100 grams
EXAMPLES

11. NAME BIOLOGICAL
SOURCE
ACTIVE
CONSTITUENTS
USES FIBRE
CONTENT
WHEAT Triticum aestivum Linn.
(Gramineae)
cellulose, hemicellulose
, and β-glucans.
Controls obesity
anti-
inflammatory,
prevents gall
stones, anti-
cancer.
2.7g per 100g
CASHEW NUTS Anacardium occidentale
(Anacardiaceae)
β-carotene, lutein, α-
tocopherol, γ-
tocopherol, thiamine,
stearic acid, oleic acid
and linoleic acid.
Lowers risk of
gall stones,
antioxidant,
helps in weight
loss, lowers
blood pressure.
3.3 g to 1.5 g per
100g.
EXAMPLES

12.  SOLUBLE DIETARY
FIBRE
• Soluble fibre attracts water and turns into
gel during digestion.
• This slows digestion.
• Some types of soluble fibre may help to
lower risk of heart disease.

13. Contd.
• It is found in legumes, grains, some fruits and vegetables. It is
found in psyllium a common fibre supplement.
• Classification:
Pectin
Gums
Mucilage

14. PECTIN
• Linear polymer of galacturonic
acid connected with α (1→4)
bonds
• Highly water-soluble
• Completely metabolized by
colonic bacteria
• Gelling behaviour → decrease
the rate of gastric emptying
• Food Sources: - Fruits, veg.,
legumes, potato

15. GUMS
• Sticky exudations formed in
response to trauma
• Highly branched
polysaccharide
• Absorb water in the
intestine, mixes the food into
gel and slow down rate of
digestion and absorption
• Guar gum is a
galactomannan isolated from
the seed of Cyamopsis
tetragonolobus
(guar), Fabaceae.
• Guar arabic (Acacia tree): -
complex arabinogalactan
polysaccharide in admixture
with a glyco-protein.

16. MUCILAGES
• Secreted into the endosperm of plant seeds where they act to
prevent excessive dehydration.
• Fruits: - Fig, Lemon, Quince, Almond.
• Vegetables: - Green beans, Okra, Celery, Potato, Parsley.
• Seeds :- Isabgol ( Plantago ovata, Plantaginaceae. )

17. NAME BIOLOGICAL
SOURCE
ACTIVE
CONSTITUENTS
USES FIBRE
CONTENT
PEAR Pyrus communis L
(Rosaceae)
Acids: oleic, palmitic,
glutamic, & ascorbic.
Beta carotene &
Arbutin. Amino acids:
glycine, arginine,
alanine.
Diuretic, Anti-
inflammatory,
Antioxidant.
5.5 grams in a
medium-sized
pear, or 3.1 grams
per 100 grams.
MANGO Mangifera indica
(Anacardiaceae)
Saponins, triterpenes,
Xanthones, Tannins,
Carotenoids, catechin
and mangiferin.
Antioxidant &
Anti diarrhoeal.
more than 1.5
grams of total
fiber in a 100-
gram.
EXAMPLES

18. NAME BIOLOGICAL
SOURCE
ACTIVE
CONSTITUENTS
USES FIBRE
CONTENT
CARROT Daucus carota L.
(Apiaceae)
Carotenes, Alpha- and
beta- carotenes
&Vitamin A and C.
Antioxidant,
Anticancer,
helps to control
Diabetes.
3.6 grams in one
cup, or 2.8 grams
per 100 grams.
This is very high
given their low-
calorie content.
AVOCADO Persea americana
(Lauraceae)
vitamin E, vitamin C,
beta-carotene,
thiamine, riboflavin,
nicotinic acid, and
folate.
Anti-
inflammatory,
Antioxidant.
10 grams in a
cup, or 6.7 grams
per 100 grams.
EXAMPLES

19. NAME BIOLOGICAL
SOURCE
ACTIVE
CONSTITUENTS
USES FIBRE
CONTENT
RICE Oryza sativa Linn.
(Gramineae)
Tocopherol, amylose,
amylopectin, oleic and
linoleic acids.
food oil,
cosmetics,
demulcent,
nutritive.
Brown rice
contains a fair
amount of fiber
(1.8%), while
white rice is very
low in fiber
(0.3%)
BARLEY Hordeum vulgare
(Gramineae)
Tocopherols,
Tocotrienols, Vitamin
E.
Reduce chronic
inflammation,
prevents
constipation,
bulking agent,
anti
hypertensive.
6 grams of fiber
in barley, 1.5
grams are soluble
and 4.5 grams are
insoluble.
EXAMPLES

21. RESISTANT STARCH
• Escape digestion in the small intestine of human beings and pass to
large bowel where it is fermented.
• These starches are “invisible” (doesn’t alter the appearance, taste or
texture of foods).
• Physico-chemical properties: - swelling, viscosity increases, gel
formation.
• Food sources: -beans, legumes, rice and potato.
• Miscellaneous

22. AMYLOSE
• Straight chain.
• Limit surface area exposed
for digestion.
• Food high in amylose- digest
more slowly.
• Less spike in blood glucose.
• Alpha-1,4-glycosidic bonds
are present.

23. AMYLOPECTIN
• Highly branched
• Leaving more surface area
available for digestion
• Broken down quickly
• Large rise in blood sugar
• Alpha-1,6-glycosidic bonds is
present.

24.  PHYSICO-CHEMICAL PROPERTIES OF DIETARY FIBERS
• WHC has direct relationship between absorption of
water by food in the intestine and facilitation of
digestion and absorption of nutrients in the body
Water holding
capacity
• Hydration & fat absorption capacity
increases with decrease in particle size.Particle size
• Molecular weight and chain length increases, viscosity of fibre
in solution increases.
• More branching and ionic group increases solubility.
Viscosity and
solubility
• Prevents reabsorption of bile salts in small intestine.
• Reduced blood cholesterol.
• Lignin show strong binding property.
Binding of ions and
organic molecules

25.  SAFE LEVEL OF TOTAL FIBER
CONSUMPTION
Avg.
Intake for
Children
• 1–3 years 19
g/d 4–8 years
25 g/d
• 4–8 years 25
g/d
Avg.
Intake for
Boys
• 9–13 years 31
g/d
• 14–18 years 38
g/d
Avg.
Intake for
Girls
• 9–13 years 26
g/d
• 14–18 years 26
g/d
Avg. Intake
for Men
• 19–30 years 38
g/d
• 31–50 years 38
g/d
• 51–70 years 30
g/d
• More than 70
years 30 g/d
Avg. Intake
for Women
• 19–30 years 25
g/d
• 31–50 years 25
g/d
• 51–70 years 21
g/d
• More than 70
years 21 g/d

26.  DETERMINATION
OF
DIETARY FIBER

27.  TOTAL
DIETARY
FIBER ASSAY

28. FATE OF DIETARY FIBER IN
HUMAN DIGESTIVE SYSTEM
• Polysaccharides like starch and cellulose from plant
foods are the most abundant carbohydrates that
human beings eat.
• Starch are completely hydrolyzed by enzyme action
to yield free D- glucose.

29. Mouth
• Chewing → acted by salivary
amylase → break alpha (1→4)
linkages in starch Small intestine .
Small
intestine
• Process continued in the small intestine by the
action of pancreatic amylase secreted from
pancreas into duodenum.
• Cellulose → cannot hydrolyzed Large intestine
Large
intestine
• Fermentation → colonic bacteria on food
mass→ gases and short-chain fatty acids

30.  FUNCTIONS OF DIETARY FIBER
• Viscous fibers promote a feeling of
satiety or fullness after a meal.
• High fibre foods slow gastric emptying .
• Calorie content < 4 kcal/g.
WEIGHT
REDUCTION
• Viscous fibers lower serum cholesterol
by reducing the absorption of dietary
cholesterol and also reduce the amount
of cholesterol manufactured by liver
REDUCING
CHOLESTEROL
LEVELS

31. • Due to ability of fibre to increase stool
weight.
LAXATION &
REGULARITY
• Viscous fibers help normalise blood
glucose levels by delaying the absorption
of glucose after a meal.
NORMALIZING
BLOOD SUGAR
LEVELS
• Fermentable fibers help maintain healthy
populations of friendly bacteria.
• Decreased transit times → decrease protein
breakdown → accumulation of putrefactive
substances ( ammonia, phenols, amines and
hydrogen sulfide ) in colon.
PREBIOTIC
POTENTIAL –
HEALTHY COLON

32. Problems due to excess consumption of Dietary
fibre
Mineral Deficiency
Flatulence

33. REFERENCE
• PHARMACOGNOSY-50TH-S-B-Gokhale-P-Purohit-Dr-C-K-Kokate
• https://pubs.acs.org/doi/abs/10.1021/jf904580k
• https://www.researchgate.net/publication/237014153_Dietary_Fibre_in_foods_A_review
• https://www.megazyme.com/technical-support/dietary-fiber/history-of-dietary-fiber-measurement
• https://www.healthline.com/nutrition/22-high-fiber-foods#section6
• https://www.phytochemicals.info
• https://www.nutrition-and-you.com/index.html
• https://www.slideshare.net/TaruNegi/8-oct-master-seminar
• https://www.glnc.org.au/grains-2/grains-and-nutrition/cereal-fibre/
• https://www.slideshare.net/poonvija/dietary-fiber-45823931
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3550877/