1
Q
What are the 3 ways to leaven a product?
A
1) physical leavening (stirring, kneeding)
2) chemical leaving (baking powder/soda)
3) biological leavening (yeast)
2
Q
Baking soda and powder are examples of which type of leaving
A
Chemical leavening
3
Q
Yeast is an example of which type of leavening
A
Biological leavening
4
Q
What are the 4 main types of leavening agents?
A
1) air
2) steam
3) CO2 - baking soda, baking powder
4) yeast fermentation
5
Q
For every degree temp rises, volume of air expands by _____
A
1/273x
6
Q
what water is heated and turned to gas, volume increases by ____x
A
1600x
7
Q
Why do gluten balls expand?
A
Because of steam
8
Q
What % moisture do you want in dough?
A
45-50%
once you have 50-55% moisture in the dough, you wont get any improvement
9
Q
What is the chemical reaction for CO2 as leavening agent?creates soapy taste)
A
2NahCO3 –> Na2CO3 + H2O + CO2
2 sodium bicarb –> 1 sodium carb + water + c.di
10
Q
what gives things a soapy taste?
A
sodium carbonate
11
Q
What is the chemical formula for leavening if you want to ensure there is no soapy taste due to sodium carbonate
A
1) NaHCO3 + HX –> NaX + H2CO3
(1 sodium bicarb + acid –> sodium salt of acid + carbonic acid
2) H2CO3 –> H2O + CO2
(Carbonic acid –> water + carbon dioxide)
12
Q
What is the chemical formula for leavening using cream of tartar?
A
NaHCO3 + HKC4H6O6 –> NaKC4H4O6 + H2O + O2
(sodium bicarb + cream of tartar –> sodium salt of tartaric acid + water + oxygen)
tartartic acid formula is C4H6O6
13
Q
what is the chemical formula for tartaric acid?
A
C4H6O6
14
Q
What is the difference between cream of tartar and tartaric acid?
A
For cream of tartar (?), one of the hydrogens has been replaced by a potassium ion. But it is still nice and acidic
15
Q
What is baking powder composed of?
A
- baking soda
- acid/acid salts
- inert filler
16
Q
BP is made up of baking soda, acid salts, and inert fillers.
What type of acid salts does baking powder usually contain?
A
Phosphate salts or sulphate salts:
1) calcium monophosphate - CaH4(PO4)2
2) Sodium Aluminum sulphate - Na2SO4 - Al2(SO4)3
17
Q
When it comes to leavening, what is the difference between single-acting baking powder and double-acting baking powder
A
Single-acting:
- contains 1 acid salt (ie made of sodium bicarb + cream of tartar)
- starts producing CO2 when hydrating, because cream of tartar is cold-water-soluble, so CO2 production begins during mixing process
Double-acting
- contains 2 different acids.
- cold-water-soluble salt like Calcium monophosphate CaH4(PO4)2
- Hot-water-soluble like sodium aluminum sulphate Na2SO4-AL2(SO4)3
18
Q
What is the chemical formula for yeast leavening?
A
C6H12O6 –> 2C2H5OH + 2CO2
1 glucose –> 2 ethanol + 2 carboin diox
19
Q
How does yeast leavening occur?
A
when you use yeast on glucose, the ethanol produced will enter gas phase and leave, and the CO2 will act as leavening agent
20
Q
What is the difference between active dry yeast and instant dry yeast
A
Active dry yeast:
- it is dehydrated product/needs rehydration at specific temp (43-46 degrees)
Instant dry yeast
- doesnt need rehydration
- water temp control isnt as important
21
Q
What water temperature do you need to use for active dry yeast?
A
43-46 degrees
22
Q
What makes instant dry yeast different than active dry yeast? (2 things)
A
1) smaller particle size - can dissolve easier in batter
2) can contain emulsifier
23
Q
How does shortening tenderize a flour mixture?
A
By limiting the length of the gluten protein structures that develop
24
Q
______ gluten strands lead to tender product, while ____ gluten strands lead to tough product
A
short = tender long = tough
25
How does shortening tenderize a flour mixture?
1) it cuts fat into the flour and introduces multiple layers of fat that separate the starch
2) the fat acts as a lubricant by limiting the association between the starch and protein --> llimits guten development
26
why is lard softer than beef tallow?
lard has 2 double bonds, making it unsaturated
beef tallow has less linoleic acid
27
vegetable shortening has the best spreadability between __ and ___ degrees celsius
15-35 degrees celsius
28
butter/margarine is made up of __ % fat and ___% moisture
80% fat
| 20% moisture
29
What are 3 reasons why vegetable shortening is good for pastry making?
1) good spreadability of fat
2) has been whipped with nitrogen gas (so there is air incorporation which helps with leavening)
3) has emulsifiers, which blend aqueous and hydrophobic phases
30
What type of emulsion is butter?
a water in oil emulsion
31
what are the 3 types of fat/water mixtures?
1) oil in water emulsion (salad dressing)
2) water in oil emulsion (butter)
3) low fat spread (when movie popcorn gets soggy)
32
what are the key characteristics of pastry?
1) flakiness
| 2) tender enough to cut with a fork
33
what are 4 examples of pastry crust?
1) pate brisee (all butter)
2) pate sucree (fat, sugar, egg)
3) pate sablee (fast, sugar, egg)
4) flaky pie dough
34
Which pie crust is cookie like - flaky and light, and has fat, sugar, and eggs
pate sucree
35
what pie crust is cookie like, crumbly like shortbread, and has sugar and fat
pate sablee
36
which pie crust only uses butter
pate brisee
37
What are 2 fat characteristics involved in the flakiness/tenderness of pie crust?
1) shortening power (more shortening power = more spreadable)
2) temperature sensitivty
38
which fat has the greatest shortening power?
liquid fats (more unsaturated bonds)
39
For pastry crust, what should the ratio of fat: flour be?
1 fat: 3 flour OR
| 1 fat: 2 flour
40
What are 3 things you want in the dough when pastry making
1) stiff dough
2) 1:3 or 1:2 ratio of fat to flour
3) low amount of handling
4) short gluten strands
41
what dictates the length of the gluten strand produced when making pie crust? (4 things)
1) choice of fat
2) temp of water
3) amount of handling
4) how the fat is cut into the mixture
42
What is the difference between cake flour and all purpose flour?
Cake flour:
- has less protein
- has less gluten
- comes from softer wheat
- more starch/more gelatinization
43
How does sugar affect cake products?
1) it introduces air during creaming
2) it delays starch gelatinization by binding water so its not available for other uses
3) it inhibits protein denaturation. more sugar = high temp needed for denaturing
44
What is the difference between a shortened and unshortened cake?
Shortened cake
- made with leavening agents like baking soda + baking powder (shorten glutens trands)
- has fat and butter
Unshortened cake
- lots of eggs/egg white
- beating eggs introduces air
45
Why is shortening/creaming (mixing fat and sugar) good for leavening?
it introducers air
46
Egg proteins have a ____ effect on baking
toughening effect. but this is offset by the fact that yolk contains emulsifers (lecithin)
47
Egg yolk contains this emulsifier
Lecithin (hydrophobic and hydrophilic components stabilize fat and make them stable
48
How many species of plants make up the bulk of crops?
14
49
What are Pulses?
Legumes, Chickpeas etc.
| Source of fibre, PUFAs
50
What is a fruit?
the mature ovary of a flower, including the seeds
51
What is the pericarp?
the flesh of the fruit
52
What is the carpal?
Seed area of fruit (etc: apple core area)
53
What is the bottom of an apple called?
Stamens/Sepal
54
The outer rind of a citrus fruit is called
Flavedo
55
Where are the essential oils and flavours of a citrus fruit located?
In the outer rind (Flavedo)
56
The white pithe on an orange that we pick off is called
The albedo
57
What is the albedo?
the white pithe we pick offo our oranges.
| Good source of pectin
58
What are the 3 types of fruit?
1) simple fruit
2) aggregate fruit
3) multiple fruit
59
when there is a single mature ovary in a single flower, this is called
a simple fruit
60
What is a simple fruit?
a single mature ovary in a single flower
Examples: Pomes, drupes
61
Apples, pears, and citrus are all examples of
Pomes (Simple fruit)
62
When you have multiple stamens/ovaries in a single flower, this is called:
Aggregate fruit
63
What are aggregate fruit?
Multiple stamens/ovaries in a single flower
Examples: berries
Have multiple juice sacs
64
Figs and pienapples are examples of this type of fruit
multiple fruit (produced by a cluster of multiple flowers)
65
What is multiple fruit?
Fruit produced from a cluster of multiple flowers
66
What is the difference between fruit and vegetables?
Different balance of sugar and starch as they mature:
- as fruit ripens - increased sugar, decreased starch
As veggies ripen - increased starch, decreased sugar
67
In what ways are fruits and veggies similar?
1) rigid cell wall
2) primary cell wall made of cellulose and hemicellulose
3) secondary cell wall made of lignans
4) pectins (interior of most fruit. in albedo of oranges. unripened fruit have more pectin
68
the bottom of asparagus has fibrous wood-like quality due to this:
lignans
69
_____ is an interior structure of most fruit
pectins
70
Name examples of bulb vegetables
Garlic, Leek, onion
71
Garlic, leek, and onions are examples of this type of vegetable
bulbs
72
beets, carrots, and radishes are examples of this type of vegetable
root
73
What is a tuber
- an underground stem structure
- can give rise to new plans
- Examples: white potato, sweet potato, artichoke
74
artichokes are examples of this type of vegetable
tuber
75
Brussel sprouts, celery and cabbage are example of this type of veggie
Stems
76
What are the different classifications of veggies (6)?
1) bulb
2) root
3) tubers
4) stems
5) leaves
6) pods and seeds
77
The outer part of the plant is called
cell wall
78
the inner surface of a plant is called
cytoplasmic membrane
79
what is the cytoplasmic membrane of a plant
the inner surface of the plant
80
Where are starch granules synthesized in plants?
Leucoplast
81
What do leucoplasts contain? what do they do?
they contain starch (amylose and amylopectin)
| they synthesize starch granules
82
Where is the chlorophyll contained in plants
Chloroplats (lipid solbule)
83
where are the carotenoids and lycopene found in plants
the chromoplast
84
___ increases in size as plant cell ages
Vacuoles
85
What doe the vacuoles of plants contain?
water and air
86
what do the vacuoles of plants do?
this is where the water soluble pigments are found like anthocyanins (reddish purples)
87
Whay gives fruits and veggies their firmness/crispness?
High water content!
88
what is the water content of wet crops vs dry crops
wet crops have 70-90% water content
| Dry crops have less than 20% water
89
Why cant you keep beans forever?
they have moisture!
90
Why does celery become limp?
evaporation of mositure from the plant.
| Loss of turgor pressure (positure in plant pushing against the cell wall)
91
When the moisture in a plant is pushing against the cell wall, this is called
turgor pressure
92
____ Make up 75% of the solid matter of plants
carbs
93
Carbs make up ____ of the solid matter in plants
75%
94
2 examples of dietary fibre in fruits and veggies
1) pectins (pithe of citrus)
| 2) cellulose
95
pectin is an example of
dietary fibre
96
cellulose is an example of
dietary fibre
97
How much protein does soft wheat contain?
7-9%
98
how much protein does hard wheat contain?
12-14%
99
What makes up the protein in wheat?
1) glutenin + gliadin = 80% of protein in wheat (water insoluble)
2) albumins + globulins = 20% of protein in wheat (water soluble in salt water)
100
soybeans contain which types of protein
globulin proteins
101
lipid content is expressed in terms of ______
dry weight basis
102
coconut oil and palm oil have _____ fatty acids
medium chain fatty acids
103
How many double bonds does olic acid have?
1
104
How many double bonds does linolenic acid have?
3
105
How many double bonds does linoleic acid have?
2
106
why is citric acid tart?
because it has 3 carboxylic acid groups (COOH), and each becomes ionized and will release 3 Hydrogen ions
107
which form of acid contributes to the flavour in apples and grapes?
malic acid
108
Malic acid has ___ carboxylic acid groups
2
109
_____ makes calcium less bioavailable because it binds the calcium, so there is less available for absorption
oxalic acid
110
Parsley and potatoes are good sources of:
ascorbic acid (Vitamin C)
111
vitamin C is: water soluble or insoluble?
water soluble
112
Vitamin C is an antioxidant and a reducing agent
113
What are the 2 forms of ascorbic acid (Vitamin C)?
L-ascorbic acid (natural form)
| D-dehydroascorbic acid (Oxidized form)
114
what are good sources of vitamin A?
vegetables!
115
what it the precursor for vitamin A?
beta carotene
116
Wheat flour is a good source of:
vitamin B
117
what is the best carotenoid for pro-vitamin activity?
beta carotene
118
What are the 3 types of carotenoids?
1) beta carotene = orange
2) lycopene = red
3) Astaxanthin = red
119
Astaxanthin belongs to this family of pigments
carotenoids
120
lycopene belongs to this family of pigments
carotenoids
121
How are caroetenoids affected by heat and acid?
Cuases the tans gemoetry of the double bond to convert to cis--> leads to duller colour
122
What does oxidation of carotenoids do?
it leads to decreased colour due to conjugated double bond system
123
Chlorophyll is: water soluble or fat soluble?
fat soluble
124
What are the different forms of chlorophyll?
1) chlorophyll A (2.5x) --> bluish green
| 2) Chlorophyll B (1x) --> green
125
How does heating and acid affect chlorophyll?
the magnesium ion is replaced by 2 hydrogen ions, and it changes chlorophyll to pheophytin --> dull, olive green
126
when chlorophyll is put into basic conditions, it converts into this
pheophytin
127
How do we prevent the formation of pheophytin from chlorophyll?
use a base like sodium bicarbonate
128
How does sodium bicarbonate keep the broccoli green?
it stabilizes the magnesium ion and removes the phytyl gtup, making CHOROPHYLLIN (water soluble version of the molecule)
129
what is the water soluble version of chlorophyll?
chlorophyillin (this is why [lants get mushy when you add sodium bicarbonate
130
Cyanidin and peonidin are 2 examples of:
anthocyanins
131
Why are anthocyanins less stable?
because they are pH sensitive
132
anthocyanins are part of which family of pigments?
family
133
anythocyanins are: water soluble/insoluble?
water soluble
| they are found in the vacuoles of plant cells
134
what is a flavillium cation?
it is an unsaturated carbon ring, with 1 oyxfgen.
| found with anthocyanins
135
when blueberries turn dalk blue in bake blueberyr muffin, this is due to:
the anthocyanins
136
why are freeze dried blackberries ligther in colour?
its dehydrated so moisture is removed --> decreases colour
137
which pigment is responsible for the whites and yellows of onion and cauliflower?
anthoxanthins / leucoxanthings
138
Under acidic conditions, anthoxanthins turn:
why
139
Anthoxanthinsa re part of this family of molecules
Flavenoids (unsaturated rigng with hydroxil group)
140
which pigment is responsible for the colour in beets?
Betalains
141
What are the 2 types of betalains (colour in beets):
betacyanin - red
| Betaxanthin - yellow
142
in basic conditions, betalains (beets) turn ___
in neutral conditions, betalains (beets) turn ___
in likely acidic conditions, betalains (beets) turn ___
in very acidic conditions, betalains (beets) turn ___
basic = yellow
Neutral = blue
acid - red
very acidic = violet
143
what is the difference between betalains and anthicyanins?
| betalain contains nitrogen, which has cation characteristic that dictates pH sensitivity
144
Enzymatic browning is due to:
oxygen exposure
145
What are some examples of enzymatic browning?
apple slices browning
146
Explain the process of enzymatic browning
Tyrosine --> converts to dopa-quinone --> melanin by polyphenol oxidase enzyme (PPO)
147
which enzyme is resonsible for enzymatic browning?
PPO
148
What are 4 ways to prevent enzymatic browning?
1) reduce the pH
2) decrease the water activity of reaction conditions by adding sugar or salt
3) reduce oxygen exposure by submerging in water
4) add reducing agent like ascorbic acid (vitamin c)
149
why does adding an acid (reducing pH) prevent enzymatic browning?
if you make the environment acidic then you are denaturing the protein responsible for enzymatic browning
150
Why does adding sugar or salt reduce enzymatic browning?
Sugar has hydroxyl groups that hydrogen bind to water, so water cant help tyrosine move into active site
NaCl hydrogen binds to water. Na+ reacts with the oxygen on molecule and Cl will react with hydrogen
151
which protein is responzible for enzymatic browning
tyrosine
152
why does submerging apples in water only work up to a point to prevent enzymatic browning?
once dopa-quinone is formed from tyrosine, it doesnt matter if you inhibit PPO or not, you will still get melanin formed
153
Why is unripened fruit firm?
- Due to the high pectin concentration
| - the starch components havent been changed to sugar yet
154
What is the ripening hormone in fruit called?
```
ethylene gas (CH2CH2)
- it is in higher concentration as fruit ripens
```
155
Why do you put unripened fruit next to ripened fruit in a bag?
Ripened fruit gives off ethylene gas
| If you put this next to an unripened fruit, it will help it ripen
156
What are 3 ways to slow down the ripening of a product?
A) decrease the temperature
B) controlled atmosphere storage
C) Modified atmosphere packaging (MAP)
157
what is controlled atmosphere storage?
- a way of slowing down the ripening of a product
- used for walk in fridges
- increase the concentration of CO2 to slow down metabolism
158
What is post harvest physiology?
It is the continued respiration and enzyme activity of plant tissues
159
Why do we refrigerate food?
to reduce the potential effect of metabolic heat given off by postharvest physiology
160
What is modified atmphoshere packaging (MAP)
- It is one way we slow down the ripening product of foods
- it involves altering the air around your fruit
- done with high value fruit like cherries
- need to ensure the environment doesnt become anaerobic
161
What type of method is used to slow down ripening of high value fruits like cherries?
modified atmosphere packaging
162
Increased respiration = _____ shelf life
decreased shelf life
163
what is senescence?
- when something gets past optimal ripeness
| - the early stages of fruit decay
164
Cold temps = _____ respiration rates = _____ storage life
cold temps = decreased respiration = increased storage life
165
what is climacteric rise (related to fruits)
a sudden increase in respiration rate as a product ripens
166
a sudden increase in respiration rate as a product ripens is called:
Climacteric rise
167
Avocados and bananas should be stored at:
10 degrees
168
when cucumbers get pitted skin, and damage to skin pigments, this is likely due to:
chilling injury
169
According to Canada's food guide, proteins should make up ____ of caloric intake
20%
170
what are examples of structural proteins?
1) keratin
2) actin
3) myosin
171
Keratin, actin, and myosin are all examples of:
structural proteins
172
What are examples of functional proteins?
a) enzymes (lysozome in eggwhite)
b) protein-based hormones (growth factors)
c) trypsin inhibitor
d) peptides (caseins)
173
growth factors are examples of:
protein based hormones
174
Why do we soak beans?
because they contain trypsin inhibitors - trypsin is needed for digestion. if you have an inhibitor, you're not getting the full nutrients.
175
What is the major digestion product from milk proteins?
Caseins
176
What is the biologically active peptide that helps calcium stay soluble in the small intestine?
casein phosphopeptides (isolated from caseins)
177
What are the 3 main casein phosphopeptides
1. As1 casein
2. As2 casein
3. B casein
178
What are the different types of proteins/amino acid composition?
1. simple proteins
| 2. conjugated proteins
179
What are simple proteins?
- basic polypeptide chains of amino acid residues
- has no sugar molecules
Example of a simple protein: olvalbumin (key egg white protein)
180
Olvalbumin is found in ____ and is this type of protein
found in egg white.
| It is a simple protein
181
Post-translationally modified proteins are called
Conjugated proteins
182
What are conjugated proteins
- they are post-translationally modified proteins
- they have gone from rough ER to golgi apparatus
- there are 2 types:
1) glycosylated conjugated proteins - when sugar groups are added to the proteins
2) phosphorylated conjugated proteins
183
what is an example of a phosphorylated conjugated protein?
Casein
184
What is an example of a glycosylated conjugated protein?
ovomucin (egg white protein)
185
How much protein does dairy milk contain?
3.6% protein (80% caseins, 20% whey)
186
How does yogurt form?
it is the result of lactic acid fermentation and of casein proteins that give us a semi-solid gel
187
meats are a good source of what type of iron
heme iron
188
there are 4 different levels of structures for protein.
The level that talks about alpha-helices and beta-pleated sheets is which level
secondary structure
189
what are the 4 types of secondary structure proteins?
- alpha helix
- beta pleated sheet
- beta bend
- random coil
190
what is happening at the tertiary level of proteins?
intramolecular bonding (within the same polypeptide chain)
191
what happens at the quaternatry structure of proteins?
intermolecular bonding
| example: actin reacting with myoslin in muscle contraction
192
What level of protein structure can denaturation occur in?
secondary, tertiary, quaternary (not primary)
193
what is coagulation
going from the native, soluble protein to an insoluble gel protein by adding heat
194
when you go from a native, soluble protein to a gel, insoluble protein with the addition of heat, this is called
coagulation
195
what is 'water holding capacity'?
the ability of a protein gel to hold water in its structure
196
making a baked custard and making an omelette are both examples of
coagulation
197
how many grams is a large egg?
50 grams
198
what is the main fatty acid in egg?
oleic acid (16 carbons, 1 double bond)
199
How do you get omega 3 eggs?
feed flaxseed to the hens
200
what is the relationship between cholestrol and eggs?
Cholesterol is important for cell membrane integrity and fluidity.
201
how do you convert kcal to kjoul?
x 4.168
202
What is the difference between a white egg shell and a brown egg shell?
```
Brown = rhode island reds
White = Leghorn chickens
```
203
What determines the colour of egg yolk?
feed of hen.
Paler yolk = wheat diet
rich yellow yolk = corn diet
orange yolk = carotenoid enrichment
204
where is the air cell of an egg located?
at the rounder part of the egg
205
what happens to the air cell as the egg ages?
the air cell will increase in size because the shell is porous so it can do gas exchange
206
Why do stale eggs float?
Due to the increase in the size of the air call.
Also, in fresh eggs the air cell is at the centre of the gg.
In stale eggs the air cell shifts
207
what is the pH of egg yolk?
| What is the pH of egg white?
pH of egg yolk = 6-6.1
| pH of egg white = 7.6-6.9
208
What is chalaza?
- the fibrous protein thread at the end of the yolk
| - anchors the yolk at the center of the egg
209
what is the fibrous protein that anchors the yolk to the centre of the egg called?
the chalaza
210
Riboflavin is found in which part of the egg?
the thick albumin
211
why is there a grey ring around the yolk of an egg
happens when you cool the egg slowly - the hydrogen sulphide from the eggwhite migrates to the yolk surface and interacts with iron in the egg yolk to create ferrous sulphide
212
What happens when an egg ages?
- air cell gets bigger and moves towards the end of the gg
- CO2 and pH go up
- Chalaza becomes weaker
- thick albumin becomes weaker
213
what is a naturally present contaminant in eggs?
Salmonella
214
how much feed do you need to get 12 good egs?
1.4kg of feed
215
how many days does it take to go form hen to retailer?
5-7
216
What do they do at the grading station for eggs?
- assess quality
- asses size
- washing eggs
- candling eggs
- weighing and sizing eggs
- packaging eggs
217
What does the grading of an egg as A, B, or C depend on
1) position of the yolk
2) size of air cell
3) quality of the shell
218
Egg white (albumin) is made up of the following 4 proteins:
1. ovalbumin (54%)
2. ovotransferrin
3. Ovomucoid
4. Ovomucin
219
this egg white protein binds Fe2+ or Fe3+ in the egg white
ovotransferrin
220
this egg white protein is a conjugated glycoprotein (has a sugar group on it)
ovomucoid
221
This egg white protein is a filamentous protein. and is found in much higher concentration in the thick albumin than the thin ambulin
ovomucin
222
this eggwhite protein is important for the aesthetics of freshness of the egg
ovomucin
223
this egg white protein is a water soluble simple protein
ovalbumin
224
Egg yolk is made up of which proteins?
lipoproteins (phospholipids)
225
what is the key emulsifier/phospholipid in egg yolk?
lecithin aka phosphatidylcholine
226
What are 5 factors that affect the denaturation of egg proteins?
1) dilution - if you dilute with milk, temp for denaturation goes up
2) heating - direct heating vs. indirect heating
3) method of agitation - slow constant stirring vs no stirring
4) sugar - needs higher temp
5) salt - enahnces denaturation
227
what is the first step in cheese production
rennet enzyme production
228
milk fat is synthesized by
the smooth Endoplasmic reticulum
229
lactose is synthesized by
the golgii apparatus
230
milk has to be reduced from ____ degrees to ____ degrees
37 degrees to 4 degrees
231
milk is ___ % water
86-88%
232
what are the main proteins in milk?
caseins
233
How do farmers cool milk from 37 degrees to 4 degrees?
they use heat exchangers - stainless steel plates with cold water running through it
234
Which caseins are important for cheese making?
Kappa caseins
235
____ are easy to denature at temperatures about 70 degrees
whey proteins
236
what are the different types of whey proteins?
a) B-lactoglobulins
b) a-lactalbumins
c) blood proteins (like immunoglobulins)
237
what type of emulsion is milk
oil in water
238
what are the 2 primary proteins found in milk
a) Caseins
| b) whey
239
Where are milk proteins synthesized
mammary glands
240
what is responsible for the film that forms when you heat milk?
whey proteins
241
_____ makes up half of total whey proteins
beta lactoglobulin
242
What is the freezing point of milk?
- 0.57 degrees
243
Why does heating milk have a 'cooked flavour?
because
a) it releases H2S (hydrogen sulphide)
b) it causes sulphur-containing amino acids to interact with eachother
244
Why does skin formation on milk happe
245
What are the 2 general frequencies for microwaves?
2450 MHz
| 915 MHz
246
Microwaves are _______
short wavelength radio waves
247
Which has better penetration, microwaves with 2450 MHz or microwaves with 915 MHz?
915 MHz has better penetration!
915 MHz has higher wavelength --> lower frequency --> better penetration
2450 MHz has short wavelength --> greater frequency --> worse pentetration
248
What is the power output for small vs big microwaves?
small microwaves = 400-500 watts
| big microwaves = 600-700 watts
249
Why can we use glass, paper, ceramics in the microwave but not other things?
because those materials are transparent to microwave energy, so the microwave can penetrate it
250
what element for some metal to be used in a microwave, and helps with crisping?
heat susceptors on packaging (ie pupcorn bag says this side down).
Heat susceptors are thin film that is well insulated.
251
How does food heat up in a microwave?
the water molecules in the food flip back and forth (because they are polar - one side is electronegative and one side is electro-positive) and generate heat.
252
what is nonenzymatic browning?
the chemical reaction between amino sources and carbs
253
Why dont you get browning with microwaves?
because when you heat something in the micrwave the water turns into gas. it cant evaporate because it is in an enclosed enviornment.
254
how can we describe electromagnetic radiation? (2 ways)
1) frequency of the waves
| 2) length of the waves
255
How did microwaves start?
as food service application for pre-cooking bacon
256
What. is the specific heat of food (MIcrowaves)
it is the amount of caloric energy that is needed to raise the temp of 1 gram of a product by 1 degree celsius
257
Name examples of 2 coagulants
calcium sulphate and chalcium chloride
258
what does a tofu mold do?
it allows you to retain the solid tofu and let the liquid drain out the bottom
259
how do you get different textures of tufe?
it depends how much moisture you let drain away
260
What is Yuba? how does it come about?
- it is a soy protein sheet
| - comes about by letting liquid soy sit long enough --> get surface dehydration --> its the skin on top
261
What are anadromous fish?
fish born in freshwater, who live most of their lives in salt water and come back to fresh water
aka salmon
262
what type of fish are salmon
anadromous fish
FND Part 2
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