Dietary Fiber

Question 1

Dietary Fibre

Answer 1

Lignin and plant polysaccharides that are resistant to hydrolysis by the digestive enzymes in man

Question 2

Plant cell wall

Answer 2

Middle lamalla: Pectic substance & lignin

Primary cell wall: Cellulose in network

Secondary cell wall: Cellulose in parallel

Question 3

NSP

Answer 3

non- starch polysaccharide

Question 4

two types of NSP

Answer 4

Cellulose :
Cellulose
Carboxymethylcellulose

Non- cellulose polysaccharide (NCP):
Hemicelluloe
Pectins
Plant gums & mucilages
Inulin
Guar

Question 5

Principal sugars present in cellulose ?

Food souces?

Answer 5

Glucose

All cell walls

Question 6

Principal sugars present in pectic substance ?

Food souces?

Answer 6

Galacturonic acid
Arabinose/ Galactose
Mainly in fruit & veg

Question 7

Principal sugars present in hemicellulose?

Food souces?

Answer 7

Arabinose /Xylose - Cereals
Glucoronic Acid /Arabinose/ Xylose- Cereals
Glucoronic Acid /Xylose- Fruit & Veg
Xylose / Glucose

Question 8

Principal sugars present in Gums Mucilages. Storage polysaccharides?

Answer 8

Gum: Glucose - Fruit & Veg & cereals

Storage: Wide range - seeds & fruits

Question 9

Lignin is a polysaccharide? T/F

Answer 9

T
dietary insoluble fiber
it is a complex polymer of aromatic alcohols

Question 10

Energy value of NSP

Answer 10

depending on fermentation ~ 0-3Kcal/g

mean 2 Kcal/g (with ~ 70% fermentation)

Question 11

Good source of NSP

Answer 11

> 4g / portion

peas, beans, wholemeal, rye , Bran flakes, muesli

Question 12

Moderate source of NSP

Answer 12

1-4g/ portion

Most veg & fruit, nuts, Brown rice, porridage

Question 13

Poor source of NSP

Answer 13

Lettuce, grapes, white rice, biscults, cakes, corn flakes

Question 14

Nutrient content of bran & germ

Answer 14

High [Vit B] - thiamin, riboflavin, pantothenic acid

Minerals - P, Na, K , Fe, Mg, Ca

Elevated levels of basic amino acids- arginine & lysine

Phytochemicals - phytates, oxalates & phenolics

Question 15

NSP & micronutrients absorption

Answer 15

Bio- availability of some minerals may be reduce in present of NSP

Minerals bind to CHO structure, phytates, tannins & oxalates

Question 16

Wheat bran most potent dietary inhibitor of

Answer 16

Calcium
Iron
Zinc

Question 17

High NSP impair ? absorption

Answer 17

Vit D & B12

Question 18

NSP in ____ diets doesn’t compromise micronutrient status long term

Answer 18

mixed or vegetarian

Question 19

Due to NSP viscosity in solution, affects on miacronutrient utilisation by__(3)
Results in ?

Answer 19

inhibit gut movement
delay delivery of liquid from stomach
slow food mixing and digestive juices

> increase delivery iower small intestine
and reduce absorption in gut

Question 20

Example of soluble fiber

Answer 20

oat, barley, rye
legumes
bananas/ apples, berries
nuts
alliums (onions, garlic, leeks)
root veg

Question 21

example of insoluable fibre

Answer 21

Bran 
whole grain
seeds
fruit skin
beans
Cauliflower
celery

Question 22

Crude fiber

Answer 22

residue after boiling defatted food with diluted alkali and then acid.
The methods recovers 50 -80% cellulose, 10- 50% lignin and 20% of hemicellulose

Question 23

NSP (Englyst)

Answer 23

The CHO plant cell wall that originally called dietry fiber, less the lignin

Question 24

Dietary fiber (Southgate)

Answer 24

The sum of lignin nad polysaccharides that are not hydrolysed by the endogenous secretions of Gastric tract

Question 25

Unavailable carbohydrate

Answer 25

polysaccharides that are not hydrolysed by digestive tract (including lignin)

Question 26

Resistance starch

Answer 26

physically inaccessible - locked way in food matrix

highly crystalline - raw food ; cooled food

poorly hydrolysed in small intestine

fermentable

Functionally very similar to NSP

Question 27

Examples of oligosaccharides

Answer 27

Fructooligosaccharides- Inulin; Raftilose

Galactooligosaccharides- Raffinose

Mannan- oligosaccharides - Guar gum

Question 28

CODEX ALIMENTARIUS’ definition of dietary fiber

Answer 28

CHO polymers with 10 or more monomeric units, which are not hydrolysed by the endogenous enzymes in the small intestine of human and belong to the catergories

Question 29

CODEX ALIMENTARIUS’ defined dietary fiber catergories

Answer 29

• Edible CHO polymers naturally occur in food
• CHO polymers which obtained from raw material by enzymetic, physically or chemical means; have shown physiological benefit to heath and has scientific evidence that is generally accepted by competent authorities
• synthetic CHO polymers that have shown physiological benefit to heath and has scientific evidence that is generally accepted by competent authorities
• Dietary fiber may contain fraction of other compounds (that associated with the CHO in cell wall) when derived from plant. Certian analytical method may measure the other compounds as dietary fiber, excepted those if they have been extracted or re- introduced in food
• National authorities can decide whether to include CHO with 3 -9 monomeric units as dietary fiber