Week3-Course1

Question 1

In 2016, ……. Increased in the world after a steady period of decline. It now affects 815 million people.

Answer 1

world hunger

Question 2

In the developed countries, … of adults are obese.

Answer 2

28%

Question 3

What are monosaccharides?

Answer 3

the fundamental units from which other carbohydrates are built up.

Question 4

What is the active form of the carbohydrates?

Answer 4

Open chain form.

Question 5

When changing from cyclic to open chain format, one of the ____ groups becomes a ___ group

Answer 5

hydroxyl

carbonyl (either aldehyde (glucose and galactose) or ketone :fructose)

Question 6

Complete : _____ (FOS) and ___ (GOS) are _____

Answer 6

fructo-oligosaccharides
galacto-oligossacharides
pre-biotics

Question 7

What is the most common polysaccharide in food?

Answer 7

starch

Question 8

What is starch made off?

Answer 8

polymers of α-D-glucose

Question 9

What are the two polymeric form of starch?

Answer 9

1. Amylose

2. Amylopectin

Question 10

What type of bond link the glucoses to form the amylose

Answer 10

α-D-glycosidic link

Question 11

T or F : amylose has less glucose units than amylopectin

Answer 11

T, amylopectine is commonly 1000 units while amylose has 250-300 units

Question 12

Where are the branch points of amylopectine?

Answer 12

every 15-25 units

Question 13

What is the functional role of starch in food system?

Answer 13

thickening and texture modification (ONLY IF GELATINIZATION CAN OCCUR)

Question 14

What is required in order to have gelatinization?

Answer 14

Heat and water

Question 15

___ is the process by witch granules are disrupted due to the increase in energy and start to absorb water and swell

Answer 15

gelatinization

Question 16

Complete : ____ increase with _____ until it reach a certain point. Beyond that point, the ____ begins to decrease.

Answer 16

Viscosity
temperature
Viscosity

Question 17

Explain the formation of a gel

Answer 17

When gelatinized starch (that didn’t went beyond the maximum viscosity point) cool down, the hydrogen bonds reform and traps the water molecules in the newly formed 3-D structure.

Question 18

What is the difference between gelatinized starch and gel starch

Answer 18

in gelatinized starch the water molecules are trapped in the hydrogen bonds original to starch while in gel starch, the water molecules are trapped in newly formed hydrogen bonds.

Question 19

What is retrogradation?

Answer 19

firmer gels due to the over formation of hydrogen bonds between the starch chains

Question 20

What is syneresis?

Answer 20

loss of water molecules during retrogradation. The over formation of hydrogen bonds will eventually push water out of the 3-D structure.

Question 21

Name three factors that affect the gelatinization behavior and tendency to retrogradation

Answer 21

1. Size of the granules
2. amylose/amylopectin ratio
3. Average length of amylose and amylopectin

Question 22

What is the goal of chemical modification of starch?

Answer 22

obtaining a much wider range of functionality

Question 23

Give examples of chemical modification you can make to starch

Answer 23

1. pregelatinized tarch
2. hydrolysed starch
3. cross-linked starch
4. derivatized starch

Question 24

Cellulose is a polymer of _____ units:

Answer 24

β-D-glucose

Question 25

What makes the cellulose indigestable from humans

Answer 25

the β-D-glucosidic bond

Question 26

T or F : amylase are the enzymes capable of breaking the β-D-glucose polymer chain in humans

Answer 26

F

Question 27

What are the functional roles of MCC? (11)

Answer 27

``` 1- anti-caking agent 2-stabilize foams 3- stabilizes emulsions 4-replaces fats and oils 5-forms gel 6-modify texture 7-improves quality of low solids tomato sauces 8-retards ice crystal growth 9-extends starches 10-suspending agent in icecream 11-tabletting agent ```

Question 28

What is CMC

Answer 28

Carboxymethylcellulose (CMC) is a chemically modified cellulose: some CH2OH groups are replaced by CH2COOH groups to increase solubility in water.

Question 29

Complete : _____ are polysaccharides and are substance derived from shrubs or trees

Answer 29

vegetable gum

Question 30

Witch vegetable gum is used in the gluten free baked goods to improve the consistency?

Answer 30

Guar gum

Question 31

What is the difference between cellulose and starch?

Answer 31

The glycosidic bond. For starch it is alpha-d and for cellulose it is beta-d

Question 32

T or F : polysaccharides are indigestible

Answer 32

f

Question 33

T or F : the oligosaccharides don't give energy since they are not digested

Answer 33

False, because they produce organic acid and these have calories that can be used.

Question 34

T or F : Fos and Gos are digestible

Answer 34

false

Question 35

T or F : starch is unsoluble

Answer 35

true

Question 36

T or F: the starch granules are functionnally useless as is

Answer 36

true, they have a function if heated (gelatininization)