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Question 1

nutrition: FAT CONTAINS

fat: 9kcal/g
essential f.a (definition):
___ : vit
for which organs

Answer 1

• cannot produce them oruselves, get from food
• linoleic (omg6) vs linolenic (omg3)
• antioxidants: vit E & C
• for brain nerve retinal cell; also impact eye health

Question 2

classification- 3

can be either @ roomp temp
which has double bond?

Answer 2

sat = no DOUBLE BOND; solid @ roomp temp
monounsat: at least one; liquid

cis H atoms on same side; trans OPP

Question 3

id test to find the unsat degree of fat

Answer 3

= iodine values
sat fat’d take no idoine while polyunsat fat will take lots

Question 4

qualities:
______
f.a attract
- if symmetrical & _______, crystals

Answer 4

polymorphic = can take on many forms
_____ van der waal forces to bond crystal as it cools
& similar C length, form more crystals

Question 5

3 main forms of crystals: __ & ____ & ____
het vs homo (all 3 f.a chains in glycerol backbone all =)
give an e.g

e.g milk fat vs lard

Answer 5

forms: alpha, beta, beta-prime to determine which fat work best in specific food
het (diff) yield more beta prime crystal
e.g in milk at when makign forsting -> creamy txture

homo: mroe beta crystals i.e in lard

Question 6

melting point depends on___
influenced by type of fat
assym fat have lower MP

Answer 6

strength of bonding forces btw f.a: < attraction, easier to crystalise -> higher MP

• (l) fat have lower mP vs (s): longer chain; higher MP
• cis fat has more kinks -> less energ to melt vs sat fat highrr MP

Question 7

smoke point =
depends on what?
higher SP

Answer 7

temp @ which smoke comes form fat surface when heated

• depends on thermal stability when contact air
• depends on ease of glycerol hydrolysis & # of free glycerol:

higher SP _> better for high temp COOKING i.e baking

Question 8

what happens in heating of fat & smoke?

Answer 8

due to excess heating & smoke, free glycerol demp to H20 + acrolein

Question 9

compare flash point vs fire point

Answer 9

flash point = temp of volatines being ignited; cannot sustain combust
fire point = ___sustaining combus

oil once heated reach SMOKE point 0-> FLASH point -> Fire point

Question 10

plasticity =
like

Answer 10

= when it doesnt change shape permanently til stress or force applied
like solid fat, beta prime crystals in het fat

if compsoed of liquid & crystal, flexible
bt the small combo of (l) & (s) allow fat to flex

Question 11

general abt refining:
remove the phospholipid, carb protein water

Answer 11

start w/ crude oil,
wannt oxidative stable (so not susceptible to rancidity), provide nutr w/ function aspect

…..bt keep essential f.a, antioxidants, vit

Question 12

additives to protect quality in prolong storage?

3f parta

Answer 12

lecithin as emulsifier
citric acid (metal chelating) to inhibit oxidation
polyclyerol ester: to inhibit crystalisation

Question 13

rendering

Answer 13

extract fat from lve stock by melting down or reprocessing meat bone / animal byproduct
via heat or steam

Question 14

tallow: deoderised vs undeodorised
use of yellow grease_

Answer 14

is the result of rendering cattle & sheep

• deoderise (doesnt impac the taste) vs udeo (to enhance food flavour)

there is edible and indedible tallwo (or yellow grease) -> make bioful, soap & detergent

Question 15

what is so good abt marine oil?

Answer 15

typically long polyunsat fat
high in vit D & A, susceptible to oxidation
source of EPA & DHA

Question 16

which fat has 4 fat crystals?

most fat are in small_____

Answer 16

milk fat- alpha, beta, beta prime 1 & 2
most fat’re in smal globulel, surrounded by protein ^ phospholipid bilayer membrane

Question 17

what is butter

Answer 17

a phase invert
cream oil in water emulsion -> agitated -> form butter as water in oil emulsion
smaller crystal -> harder butter
winter butter harder than spring bcs seasonal cattle feed

Question 18

compare hydrolytic vs oxidative randicity?

hydrolytic: what are the catalysts?

Answer 18

hydrolytic: hydrolyzing f.a from glycerol backbone, make free f.a needs H20
w/ heat & lipase as catalysts + H20, release free f.a w. no OFF odour & taste unless short chain f.a

oxidative: has an OFF flavour & taste; w/ O exposure, in heat or light

Question 19

processing: first 3-

third is neutralise

Answer 19

• settle: separate crude oil from phospholipid, carb protein fat
• degum: remove the gum -> which can darken
• neutralise: remove free F.A w/ NaOH & residual phospholipid
  => leftover can be used to make soap

Question 20

processing: second 3-

bleach / ____ / distill steam related

Answer 20

bleach: the chlorophyll
winterisation or dewax: filter f.a -> improve the clarity
oil can look cloudier depending on trigly: bcs some molec has higher MP, crystalize -> filter
deodourisation: distill steam w/ low P to remove voltaile comp; which can vaporise

Question 21

add H+ til sat

can increase the

Answer 21

hydrogenation:

take (l) fat turn int into solid or plastic
=> < thermal and oxidative staibility
=> for shortening

Question 22

why is partial hydrogenation bad?

Answer 22

create trans f.a NOT ALLOWED
H2 bubbled through (l) oil in the presence w/ nickel catalyst -> trad hydrogenation

Question 23

interesterification

diff btw inter vs intra?

Answer 23

add f.a or rearrange glycerol backbone -> create new trig
bronds broken on f.a & reesterified on = glycerol (intra) or diff (inter)

Question 24

how to reduce trans f.a by 50%

Answer 24

low temp
high P
catalyst

Question 25

separate trigly by difference in MP, solubility & volatility

Answer 25

fractioning for processing palm oil

Question 26

what does antioxidant do? what are they specifically? | veggie fats/ synergists

Answer 26

donate H+ to free radical in veggie fat- stripped during processing 1. VIT E C b-carotene / BHA BHT propyl gallate synergists < its effeciveness by chelating w/ metals

Question 27

milk fat can 1) destabilize & coaslesce vs flocculate vs partial coalesce | crytal (liquid) fat

Answer 27

1) irreversible < in fat globule size by clumping and clustering; bt loose your id 2) is reversible clustering of fat globules w/ no loss to id partial: fat globules are held tgt by crystal and (l) fat as long as crystal structure is maintained.

Question 28

changes during frying 3. surfactats: easier to xodiate

Answer 28

1. polymerization: polyun f.a form large molec of polymers < viscosity & darken fat 2. SF lowers 3. surfactants: lower surface tension -> allow O to interact more w/ oil -> oxidate -> help w. heat transfer 4. darken

Question 29

some words on chocoalte, 3/4 of it comes from west africa cacao beans ripen on treees ____

Answer 29

comes from cacao on cacao tree: contains theobromine, a mild stimulant cacao beans ripen on trees til pods have golden orange - red color: inside nibs, polyphenol

Question 30

first step of choc processing ___ bitter ___ acid taste

Answer 30

ferment & dry: - remoes pulp, forms flavour precursor - ferment via yeast, bacteria fungi - then sun dryL to essen the bitter, astringent, acid taste

Question 31

what are acrylamides

Answer 31

colorless, crystalline solids prolly carcinogenic formed by high temp or frying using sillicone BT boiling/ steaming/ microwaving doesnt form acylamides

Question 32

T or F: roast cocoa nibs in 150-200C for 30 min.

Answer 32

F: 105 to 150. dvlop flavour through maillard browning

Question 33

# choc processing winnow, grind, mill, refine | pass through rolelr

Answer 33

- winnow: crack the bean, separate the shell -> yield the nibs - pass through a grinder: heat melst he fat -> choc mass/liquour if press, remove cocoa butter -> dry cake if grind, cocoa powder

Question 34

what is special abt duch processed cocoa powder

Answer 34

alkaline treated, ph 6-8 less bitter less polyphenols w. brown reddish color

Question 35

milk choc vs yt choc

Answer 35

milk choc contains milk sugar vs yt chocl has cocoa butter w/ no cocoa solids

Question 36

conching vs tempering | tempering produce which type of fat crystal?

Answer 36

stirring of cocoa mass @ controlled temp for up to 3 days aeration dvlop flavor = control temp to make stable, beta, V fat crystal this glossy, stable, snappy choc

Question 37

temporary vs permant emulsion

Answer 37

an emulshion when shaken then separate like vinegar dressing vs need an emulsifier like mayo

Question 38

when an emulsion breaks, it coaslece and separates into 2 layers: oil & H20. this is more likely to occur if____ | oil stirring and to fix

Answer 38

1. oil is added too quickly or too much to water 2. not enonugh agitation to reverse use a new yolk or add tbs of H20 / vingefar

Question 39

an emulfifier can be _____ & _____ | less than 6 / bigger than 8

Answer 39

1. amphiphilic : both attract to fat & oil more attrac to water in oil in water emulsion & vice versa 2. HLB (hydrophilic lipolhilic balance) - sacle of 1-20 less than 6 in water in oil emulsion; bigger than 8 in opp