Technical challenges part 4 and 5 : gums

Question 1

what is the gum that is used in high sugar food products

Answer 1

arabic gum

Question 2

what is the basic unit of arabic gum

Answer 2

arabinogalactan (galactose linked by 1,3 linkages and brnches of 1-6 with arabinan)

Question 3

what is the main property of arabic gum?

Answer 3

1. exhibit newtonian rhelogical behavior
2. weak heating capacity
3. Good resistance in an acidic medium

Question 4

What is a newtonian rheological behavior?

Answer 4

the viscosity is constant with the shear strenght. so as you increase the mixing, you won’t change the visosity.

Question 5

*** exam : What is the rheological property you want in a gum for it to be able to mimic fatty food products

Answer 5

you want it to have a thixotropic behavior : decrease in the viscosity as the mixing time increase

Question 6

what is this rheological behavior

Answer 6

thixotropic behavior

Question 7

what is this behavior

Answer 7

rheopexy behavior

Question 8

what is this behavior

Answer 8

pseudoplastic behavior

Question 9

what is this behavior

Answer 9

dilatant behavior

Question 10

What are the main functionalities of arabic gum has an ingredient

Answer 10

1. texturizer in sugar and polyols medium (maintain soft and chewy texture in candies)
2. film former avoiding fat
3. anti-crystallizing hydrocolloid (chocolate)
4. binder for sugar and polyols compressed products
5. emulsifier (form and stabilize) for oil in water
6. Stabilizer (used in the case of wines to stabilize tannins (-) and phenolic compounds(+)

Question 11

What is the source of gum tragacanth

Answer 11

from an exudate

Question 12

what is the source of gum arabic

Answer 12

tree exudate

Question 13

what is the general structure of gum tragacanth

Answer 13

linear portion : galacturonic acid linked by alpha1-4
(b1-6) branching : xylose and galactose with beta 1-3

Question 14

can the gum tragacanth produce a viscosity

Answer 14

yes

Question 15

What are the main properties of gum tragacanth

Answer 15

acid stable
very good film forming properties
produces viscosity
can form and stabilize an emulsion

Question 16

what is the uniqueness about gum tragacanth

Answer 16

that is is a bifunctional emulsifier and has a creamy mouthfeel

Question 17

what is the name of the gum that comes from the carob tree

Answer 17

locust bean gum

Question 18

what are the basic units of locust bean gum

Answer 18

galactose and mannose units (galactomanan)

Question 19

why does the locust bean gum and the guar gum are similar

Answer 19

because they both have the same basic unit of galactomanan (mannose and galactose) but the ratio is mannose/galactose different between the two

Question 20

what is the source of guar gum ?

Answer 20

come from a legum

Question 21

what are the main functions of locust bean gum

Answer 21

1. viscosity control in ice cream
2. improved texture
3. syneris control

Question 22

What is the structure of guar gum ?

Answer 22

Galactomanan (galactose and mannose)

Question 23

There is a lower galactose to mannose ratio in ____ than in ____

Answer 23

guar gum
locust bean gum
(guar gum as less galactose to mannose than locuse bean gum)

Question 24

What is the main property of guar gum ?

Answer 24

great pseudoplastic behavior : great low shear viscosity

Question 25

\*\*if a gum as a high viscosity at low shear rate, it will be better for __ and \_\_\_

Answer 25

better for pigment suspension and synerisis control

Question 26

\*\*\*If a gum as a high visocisty at low shear rate it will be good for ___ and \_\_\_\_

Answer 26

coating and spreading

Question 27

True of false : Locust bean gum is a better emulsifier and more soluble than guar gum

Answer 27

false, guar gum is a better emulsifier and more soluble

Question 28

Does guar gum forms gel

Answer 28

no

Question 29

\*\*Guar gum shows a good viscosity synergy with ___ and \_\_\_

Answer 29

xathan gum and locust bean gum

Question 30

what are the main functionalities of guar gum in food

Answer 30

1. fat substitute good mouthfeel 2. an agent that prevent crystals formation in ice cream 3. thickener in sauces and salads

Question 31

\*\* why do we use guar gum in pastries ?

Answer 31

for the synerisis control

Question 32

what is a good advantage of guar gum ?

Answer 32

it can be used as an emulsifier, a thickener and stabiliser

Question 33

\*\*\* what is the gum most compatible with sugar?

Answer 33

arabic gum

Question 34

\*\* exam : what will the best gum for thickening, emulsifying and creamy mouthfeel in high acidic food products?

Answer 34

gum tragacanth

Question 35

\*\*exam : what will be the gum with the best film forming properties

Answer 35

arabic gum because it is being used to coat candies

Question 36

what is the source of carrageenan?

Answer 36

seaweed extract

Question 37

what is the basic structure of carragennan

Answer 37

galactan units with sulfur groups

Question 38

what is the type of carragennan that will not form a gel

Answer 38

lambda carrageenan

Question 39

what is the type of carrageenan that will gel with potassium

Answer 39

kappa carrageenan

Question 40

what is the type of carrageenan that will gel with calcium

Answer 40

iota carrrageen

Question 41

What will be the effect of increasing the levels of ester sulfate groups on the carageen gum?

Answer 41

1. it will increase the solubility at low temperatures 2. it will lower the gel strenfght and even prevent gel formation

Question 42

what is the carrageen that has the highest level of esther sulfate groups

Answer 42

lambda

Question 43

what are the two carrageen seen in class that can gel

Answer 43

kappa and iota

Question 44

Is there a synergy between the locust bean gum and the ioata carrageeen

Answer 44

no but there is a synergy with the kappa carrageeen

Question 45

which one the type of carageen that is not stable to synerisis

Answer 45

the kappa

Question 46

what is the texture of the iota gel and kappa gel

Answer 46

ioata : melt in your mouth kappa: brittle like tofu and hard like cucumber

Question 47

what are the main functionalities in food of the carrageenan

Answer 47

1- binds moisture 2- stabilize emulsions 3- suspend particles 4- controls flow properties 5- produces stable gels at room temo

Question 48

carrageen has a synergism with ___ and \_\_\_

Answer 48

starch and synergism with other gums

Question 49

what is the type of carrageen that is responsible for a synergistic increase in viscosity when used with starch?

Answer 49

iota

Question 50

why is carrageenan used in chocolat milk

Answer 50

because carrageenan and casein will form a weak thxotropic gel structure (good moutfeel imitating lipids) which will suspend cocoa in milk

Question 51

what are the 4 gums we saw that are from seaweed

Answer 51

1. carrageenan 2. furcellaran 3. agar 4. alginates

Question 52

what is the structure of furcellaran

Answer 52

furcelleran is similar in the structure to kappa carrageenan : one sulfate per / two galactose units

Question 53

is furcellaran structure similar to carrageenan?

Answer 53

furcelleran is similar in the structure to kappa carrageenan furcelleran : one sulfate ester per / two galactose units kappa carrageenan : one sulfate ester / per three or four galactose

Question 54

what is the effect of having more ester sulfate in furcellaran than in the carrageenan?

Answer 54

it is more compatible with sugar and the gel will not be brittle but more elastic (which is a good thing)

Question 55

what is the source of alginate

Answer 55

brown seaweed

Question 56

what is the basic unit of alginate

Answer 56

D-mannuronate and L-glucoronate which will form GGG units or MMM units or MGM units

Question 57

in alginate : higher is the concentration of ____ units higher is the viscosity because not able to solubilise.

Answer 57

GG. because the rotation around the bond is indered and so it will not be able to be solubilized in water

Question 58

what ions needs to be present for alginate to gel

Answer 58

calcium

Question 59

what happens to the gel formation when alginate are added to high methoxy pectins

Answer 59

the gel is possible at pH acid and with low solids (sugar content) which is usually not acheivable with high methoxy pectin alone

Question 60

what are the most important function of alginate

Answer 60

1. instant gelling gent 2. emulsifying 3. thickening

Question 61

t or f :alginate have a very wide range of application

Answer 61

true (instant gelling, thickening, viscoisty)

Question 62

what are the basic unit of agar ?

Answer 62

* *agarose** : galactose and anhydro-galactose * *agaropectin** :agarose and glucuronic acid

Question 63

what are the most important functions of agar?

Answer 63

1. syneris and hysterisis 2. thermoreversible gel

Question 64

what are the two bacterial gum we saw in class

Answer 64

1. xanthan gum 2. gellan gum and curdlan

Question 65

Question 66

what is the basic uni of xanthan gum?

Answer 66

cellulose backone with branches of glucose, mannose and glucuronic acid which have pyruvate and acetate residues

Question 67

what are the important function of xanthan gum?

Answer 67

1. viscosity control 2. rapid thickening 3. emulsion stabilization

Question 68

t or f : xanthan gum can be used to form an emulsion

Answer 68

false but can be used to stabilize the emulsion