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FDSC 405 > Technical challenges part 4 and 5 : gums > Flashcards

Technical challenges part 4 and 5 : gums Flashcards

1
Q

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

A

arabic gum

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2
Q

what is the basic unit of arabic gum

A

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

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3
Q

what is the main property of arabic gum?

A
  1. exhibit newtonian rhelogical behavior
  2. weak heating capacity
  3. Good resistance in an acidic medium
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4
Q

What is a newtonian rheological behavior?

A

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

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5
Q

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

A

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

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6
Q

what is this rheological behavior

A

thixotropic behavior

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7
Q

what is this behavior

A

rheopexy behavior

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8
Q

what is this behavior

A

pseudoplastic behavior

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9
Q

what is this behavior

A

dilatant behavior

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10
Q

What are the main functionalities of arabic gum has an ingredient

A
  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(+)
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11
Q

What is the source of gum tragacanth

A

from an exudate

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12
Q

what is the source of gum arabic

A

tree exudate

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13
Q

what is the general structure of gum tragacanth

A

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

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14
Q

can the gum tragacanth produce a viscosity

A

yes

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15
Q

What are the main properties of gum tragacanth

A

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

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16
Q

what is the uniqueness about gum tragacanth

A

that is is a bifunctional emulsifier and has a creamy mouthfeel

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17
Q

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

A

locust bean gum

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18
Q

what are the basic units of locust bean gum

A

galactose and mannose units (galactomanan)

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19
Q

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

A

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

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20
Q

what is the source of guar gum ?

A

come from a legum

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21
Q

what are the main functions of locust bean gum

A
  1. viscosity control in ice cream
  2. improved texture
  3. syneris control
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22
Q

What is the structure of guar gum ?

A

Galactomanan (galactose and mannose)

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23
Q

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

A

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

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24
Q

What is the main property of guar gum ?

A

great pseudoplastic behavior : great low shear viscosity

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25
Q

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

A

better for pigment suspension and synerisis control

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26
Q

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

A

coating and spreading

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27
Q

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

A

false, guar gum is a better emulsifier and more soluble

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28
Q

Does guar gum forms gel

A

no

29
Q

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

A

xathan gum and locust bean gum

30
Q

what are the main functionalities of guar gum in food

A
  1. fat substitute good mouthfeel
  2. an agent that prevent crystals formation in ice cream
  3. thickener in sauces and salads
31
Q

** why do we use guar gum in pastries ?

A

for the synerisis control

32
Q

what is a good advantage of guar gum ?

A

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

33
Q

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

A

arabic gum

34
Q

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

A

gum tragacanth

35
Q

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

A

arabic gum because it is being used to coat candies

36
Q

what is the source of carrageenan?

A

seaweed extract

37
Q

what is the basic structure of carragennan

A

galactan units with sulfur groups

38
Q

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

A

lambda carrageenan

39
Q

what is the type of carrageenan that will gel with potassium

A

kappa carrageenan

40
Q

what is the type of carrageenan that will gel with calcium

A

iota carrrageen

41
Q

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

A
  1. it will increase the solubility at low temperatures
  2. it will lower the gel strenfght and even prevent gel formation
42
Q

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

A

lambda

43
Q

what are the two carrageen seen in class that can gel

A

kappa and iota

44
Q

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

A

no but there is a synergy with the kappa carrageeen

45
Q

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

A

the kappa

46
Q

what is the texture of the iota gel and kappa gel

A

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

47
Q

what are the main functionalities in food of the carrageenan

A

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

48
Q

carrageen has a synergism with ___ and ___

A

starch and synergism with other gums

49
Q

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

A

iota

50
Q

why is carrageenan used in chocolat milk

A

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

51
Q

what are the 4 gums we saw that are from seaweed

A
  1. carrageenan
  2. furcellaran
  3. agar
  4. alginates
52
Q

what is the structure of furcellaran

A

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

53
Q

is furcellaran structure similar to carrageenan?

A

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

54
Q

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

A

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

55
Q

what is the source of alginate

A

brown seaweed

56
Q

what is the basic unit of alginate

A

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

57
Q

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

A

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

58
Q

what ions needs to be present for alginate to gel

A

calcium

59
Q

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

A

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

60
Q

what are the most important function of alginate

A
  1. instant gelling gent
  2. emulsifying
  3. thickening
61
Q

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

A

true (instant gelling, thickening, viscoisty)

62
Q

what are the basic unit of agar ?

A
  • *agarose** : galactose and anhydro-galactose
  • *agaropectin** :agarose and glucuronic acid
63
Q

what are the most important functions of agar?

A
  1. syneris and hysterisis
  2. thermoreversible gel
64
Q

what are the two bacterial gum we saw in class

A
  1. xanthan gum
  2. gellan gum and curdlan
65
Q
A
66
Q

what is the basic uni of xanthan gum?

A

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

67
Q

what are the important function of xanthan gum?

A
  1. viscosity control
  2. rapid thickening
  3. emulsion stabilization
68
Q

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

A

false but can be used to stabilize the emulsion

69
Q
A

FDSC 405 (14 decks)

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