7

Question 1

starch (___) = a polysacc that is made up of ___
act as ___/ binding/ __ agent
__ stores energy as starch
is hydrocolloid = able to ____
2 types: __

Answer 1

carb / glucose
thickener / jelling
plant
large vol of h20
native & modified

Question 2

to break down starch,

2 process

Answer 2

w/ amylase, breaks into maltose
w/ maltase, breaks into glucose

Question 3

source of starch in food
1. cereal grains (corn __ __ rice)
2. ___
3. __ & tubers: potato, __ arrowroot

why is boba brown?

Answer 3

1. what oat
2. legumes
3. root: tapioca

boba is brown bcs brown sugar or added caramel flavour

Question 4

describe the wet milling process?

Answer 4

• clean
• grind
• slurry
• separate
• dry

Question 5

define refined starch

Answer 5

remove other components i.e protein, vit/min
add it to toher food as thickening/ bulking/ stabilising agent

Question 6

e.g of wet milling process

corn

Answer 6

for corn, native grain is separated from roots ^ tubers
corn starch + germ = corn boil

Question 7

how to reach the gelatinisation point for starch

is the final product a colloid >

ingre: water /s tarch / heat

Answer 7

when u add starch + water, have salt
apply heat: granule’ll swell, mixture thickens -> have gel @ gelatinisation point

this is a colloid

Question 8

plan

plant store energy as starch….

Answer 8

which is deposited in organised unit called granules.
=> size and shape depends on source

am. ^ am. lyose pectin is tightly packed within there

Question 9

define birefringence

how to see that cross pattern of granule?

Answer 9

= wgen starch molec is observed via microscope under polarised light

light is rotated, see the corss pattern of each granule
this pattern dissapears once granule is heated to gelatinsation point

Question 10

pure starch isolated from og plant material. elaborate.

Answer 10

native starch
- dvloped through trad plant breeding & genetic engineering
-not physc or chem mod
is “improved”

Question 11

define modified starch

Answer 11

native starch that is physc and chem modified to help food prep

Question 12

chem modified starch: hydrolysis or avcid converted

Answer 12

mix starch + H20 + acid -< dry it
make a low viscous paste & stiff gell ‘
for confectionary

Question 13

chem modified starch: cross linked

think abt how it’s better from hydrolysis

Answer 13

better viscosity and texgture
higher temp for hydration -> nore heat resistane
also resistance to shear

=> useful for canned soup & sphagetti sauce

Question 14

chem modified starch: substitution:
for frozen starch thickened food
more susceptible if…

amylose

Answer 14

prevents retrogradation which leads to syneresis:
when whip (l) into cooked starch, H20 pushed out of jell network => create this water-beading effect on surface

more susceptible if food has more amy. bcs it realigns

Question 15

gel vs colloid

Answer 15

gel = solid to semi-solid stage of colloidal solution
colloid = intermediate btw small particles in solution and large particles in suspension

Question 16

**physc **modified strach

Answer 16

instant or pregelatinisation = by cooking starch in H20, or w/ drum dryer (low temp to dry liquid)

for instant dry mix, gravies, sauce

Question 17

**physc **modified strach

pregelatin: __intergrity___smooth

Answer 17

cold water swelling = pregelatin: stach’s intergrity is retained, can swell in room temp water
=> smooth txture

Question 18

**physc **modified strach

heat

Answer 18

heat treated: starch heated beyond gelatinisation point

not enough water to increase viscosity ^ stability

Question 19

4 types of resistant staarch, which is not digsted by the **human **body

potato, whole wheat bread, green banana

Answer 19

RS1: reist digestion e.g whole grains
RS2: same thing due to compact structure i.e green banana
RS3: retrograded
RS4: only 1 chem modified starch

=> to add fibre

Question 20

what is the effect of dry heat?

dextrin

Answer 20

starch becomes more soluble, can thicken less
dvlop a brown, toasty nutty flavour
dextrinization -> starch broken down into dextrins
e.g toast

Question 21

what is the effect of moist heat?

colloid / starch paste

Answer 21

starch becomes less soluble in cold watrer
w/ heat, produce colloid
when H20 dispension is heated, make starch paste!

Question 22

changes w/ moist heat
1. gelatinisation
2. more swelling -> leaching of ___ parts
3. ____ or ___ formation
4. ____

Answer 22

2. pasting = heat starch + h20 well beyond gelatinisation / soluble
3. gel formation or gelation
4. retrograd = amylose realign (freezing or thawing encourage this)

Question 23

factors of starch paste

1. time & temp of heating: less smooth & silky (think bad custard)
2. slick & pasty mouthfeel
3. ph

Answer 23

2. agitation or stirring: if excess, disrupt the granule
3. fragmentation or hydrolysis (if pH <4, thin starch)

Question 24

factors of starch paste

sugar
fat & protein: viscosity

Answer 24

sugar compete w/ starch for H20
=> delay swelling, raise temp of gelatinisation

___-delay hydration of starch, lower rate of viscosity

Question 25

2 things ijmpt in food when combine starch + **hot** (l)

Answer 25

1. roux: blend melted fat to liquid 2. slurry: blend flour to cold water -> add to hot (l) while stirring

Question 26

list 5 basic mother sauce | fat, flour, what's different. what's special abt tomato?

Answer 26

1. bechamel: fat, flour, MILK 2. veloute: fat, flour, veal/chicken/fish stock 3. espagnole: fat, flour, BEEF stock 4. tomaro: the only one thickened w/ emulsion; rest, roux 5. hollandise: emulsifying egg

Question 27

how to cook cream soup | celelry and carrot

Answer 27

use mirepoix for flavouring thicken w/ slur / roux or pureed starchy veggie

Question 28

how to cook dessert

Answer 28

cook starch mix before add eggs: sgtarch can handle higher temp => after gelatinisation, , add egg to temper => less coagulate

Question 29

compare gel vs sol | impact...

Answer 29

gel = liquid trapped in solid contain polymer cross linked to that trapped liuid impact temp / syneresis . pH sol = liquid; can convert into gel

Question 30

polymers tht form gel: 1/ amylose 2/ 3/ 4/ ___ mold

Answer 30

1/ starch thickened pudding 2/ egg protein: egg custard 3/ pectin 4/ gelatin

Question 31

to prep unflavoured gelatin | cold -> hot -> cold -> swell

Answer 31

1. soak in cold water 2. raise temp above 35C by adding or suspend over hot water 3. remain (l) add cold 4. after gelatin swells, add fruit acid or suag

Question 31

to prep flavoured gelatin

Answer 31

add hot H20 to dissolve

Question 32

how to industrial manufacture of gelatin?

Answer 32

1. isolate collage from other components 2. purify, then refine in dry form

Question 33

in dry form, getlain has a high/low bacterial count. if add water, __ bacteria activity

Answer 33

low / increase

Question 34

what does gelation mean for felatin and starch?

Answer 34

gelatin: molec link tgt to form a **gel-typical** structure vs starch: **carb gel** formation

Question 35

what is gelatin?

Answer 35

hydrolysed from animal tissues: hides, skin, bones low protein, essential am.a => p much monessential

Question 36

effect of temp on gelatin: 1. below and above dispersion temp 2. rapid and slow cooling

Answer 36

1. all gelatin needs to cool below the dispersion temp 35C above 40C, weaker gell strength 2. rapid cooling -> sets gel faster -> softer gell

Question 37

effect of concentration on gelatin:

Answer 37

yields a faster rate of setting & firmer gel (usual % is 1.5 to 2)

Question 38

effect of pH on gelatin solution: diced fruits can_____

Answer 38

acidic-> soft gel, prevents gelation VS less acidic: stiff gel lemon juice & vinegat have strong effect diced fruits can break up gel

Question 39

# effect of ___ on gelatin salt: __ gel strength sugar: enzyme: | salt & sugar has a different effect

Answer 39

salt < gel strength while sugar yields a slower rate of setting E: bromelain a protease found in pineapple kiwi papaya can hydrolyse gelatin to balalnce, heat the protease first / use canned, heated processed frutis

Question 40

# usage of gelatin 1. foam ___ in whipped products _____ in pudding & pies 3. ___ control of ___ ___ in frozen __ & ____

Answer 40

as a basic gel (tasteless & ordourless) stabiliser thickener candy crystal size / desserts / syneresis