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129 Cards in this Set
- Front
- Back
True solutions
|
small molecules, invisible
no gels |
|
Ex of True solutions
|
kool-aid
salt water |
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Colloidal dispersions
|
small groups of molecules, macromolecules
Translucent/opaque forms gels |
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Ex of Colloidal dispersions
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proteins, cellulose, gums
|
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Suspensions
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large groups of molecules
temporary, settle out Opaque no gels |
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Ex of suspensions
|
uncooked starch
|
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Hydrophobic
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non-polar
|
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Hydrophilic
|
polar
|
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Are colloids attracted to water?
Examples |
some are, some aren't
oil in vinegar of dressings (not) gelatin in water (is attracted) |
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Where do colligative properties come into play in solutions?
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Affect true solutions
Somewhat affect colloids |
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Solid in liquid
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Solid-dispersed
Liquid-continuous Sol |
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Examples of sols
|
Skim milk (protein in water)
warm gravy |
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Liquid in liquid
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Liquid-dispersed, continuous
emulsion |
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Examples of emulsions
|
mayonnaise
french dressing |
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Gas in liquid
|
gas-dispersed
Liquid-continuous foam |
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Examples of foams
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meringue, whipped toppings
|
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Liquid in solid
|
liquid-dispersed
solid-continuous gel |
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Examples of gels
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jellies
cold gravy |
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Emulsion
|
colloidal dispersion of one liquid in another liquid, molecules of the two liquids immiscible
oil in water, water in oil |
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Emulsifiers
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helps form an emulsion, made of a polar head and non-polar tail
|
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absorption
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take a substance and make it a part of existing whole
|
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adsorption
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adhere to or hold onto the surface of a substance
|
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surfactants
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substances that adsorb onto interfaces
emulsifiers |
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D-sugar vs L-sugar
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L sugar the OH group is on the left, D sugar it is on the right
If in ring-L goes up, D goes down |
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Anomeric carbon
|
carbon which becomes assymetric when open-chain structure closes to form the ring structure
alpha or beta linkages |
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Alpha-linkage vs Beta-linkage
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Alpha-goes down
Beta-goes up |
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Monosaccharide
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simple, single sugar
|
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Disaccharide
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2 monosaccharides
|
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Oligosaccharide
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3-10 monosaccharides
|
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Polysaccharide
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10+ monosaccharides
|
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glucose + glucose
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maltose
|
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maltose
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glucose + glucose
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glucose + fructose
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sucrose
|
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sucrose
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glucose + fructose
|
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galactose + glucose
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lactose
|
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lactose
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galactose + glucose
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Invert sugar
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equimolar mixture of d-glucose and d-fructose formed by hydrolysis of sucrose
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Reducing sugar
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carb that can reduce Fehlings Reagent or Benedicts Reagent
|
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Which sugar isn't a reducing sugar
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sucrose
|
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Sweetness scale
|
lactose, galactose, maltose, glucose, sucrose, fructose
|
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Crystalline ex
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fudges, fondants, nougats, rock candy
|
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Amorphous chewy ex
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taffy, caramels, toffees, jelly bean core
|
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Amorphous hard
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taffy, caramels, brittles, toffees, lollipops, butterscotch
|
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Dextrose equivalent
|
measure of the degree of hydrolysis in corn syrups
% of reducing sugars in corn syrup |
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Crystalline def
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molecules fit into a regular geometric arrangement
|
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Amorphous def
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molecules have aggregrated in a random, disordered form
|
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Divinity, marshmallows are...
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airated non-crystalline
|
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Differences in types of candies
|
more water in crystalline
lower temp in crystalline higher ratio of interfering agents in non crystalline higher ratio of sucrose to water in noncrystalline |
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more water in (candy)
|
crystalline
|
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lower temp in (candy)
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crystalline
|
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higher ratio of interfering agents in (candy)
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amorphous
|
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higher ratio of sucrose to water in (candy)
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noncrystalline
|
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All food acids have what functional group?
|
carboxylic acid
|
|
Acids __ H+
Bases __ H+ |
give up
accept |
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Bases usually have
|
OH-
|
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Total acidity, instrument used
|
all ionized and unionized protons
titrating |
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Active acidity
|
only ionized protons, pH meter
|
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Normality
|
total acidity, molarity x ionizable H+
n=mol/L x [H+] |
|
High-low cut off in food acids
|
4.6
|
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4.6-how to cook at diff pHs
|
lower than 4.6 won't have microbes, use boiling water
greater than 4.6 pressurize steam by pressure cooker |
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buffer system
|
weak acid and salt
resists pH change |
|
most foods are __ acids
|
weak
|
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aggregate fruit
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fleshy fruit, several ovaries in one flower
|
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simple fruit
drupes pomes |
developed from one ovary in one flower
pomes-simple fruit containing a core plus seeds drupes-simple fruit containing a stone or pit enclosing a seed |
|
multiple fruit
|
cluster of several flowers
|
|
ex of aggregate fruit
|
raspberries, strawberries, blackberries
|
|
ex of simple fruit
pomes drupes |
apples, pears,
plums, cherries, peaches |
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ex of multiple fruit
|
pineapple, figs
|
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pomes-
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simple fruit containing a core plus seeds
|
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drupes-
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simple fruit containing a stone or pit enclosing a seed
|
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Parenchyma cells
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edible parts of plant tissue, food synthesized or stored
|
|
cell wall
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cellulose, hemicellulose, lignin, pectin
|
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vacuole
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water soluble compounds
|
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cytoplasm
|
protoplasm of a cell
water soluble compounds-salts, sugars |
|
plastids
|
different types contain fat soluble pigments, starch, oils
|
|
middle lamella
|
cements cells together
pectic substances, calcium, cellulose |
|
hemicellulose
|
polymers of xylose and glucose
softens when heated in basic solution dietary fiber |
|
lignin
|
polymers containing benzene derivatives
not soften when heated, woody characteristic to plants dietary fiber |
|
composition of fruits
|
water, carbs, protein, fat, minerals, vitamins, organic acids
|
|
changes in fruit during ripening
|
color
texture acidity pectic substances flavor form of carb |
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color change in ripening
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chlorophyll decreases, other pigments predominate
|
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texture change in ripening
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softens
|
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acidity change in ripening
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acidity decreases
|
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pectic substances in ripening
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remain constant-pectin decreases and pectic acid increases
|
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flavor change in ripening of fruit
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flavor volatiles increase
|
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form of carb in ripening of fruit
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starch decreases and sugars increase
|
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pectic substances
|
polymers of galacturonic acid and its methyl ester
|
|
during ripening (pectin substances)
__ --> __ --> __ |
protopectin --> pectin --> pectic acid
|
|
ethylene gas
|
plant hormone, induces ripening in some fruits
|
|
slowing fruit ripening
|
low temperature
controlled atmosphere storage-low oxygen, high CO2 modified atmosphere packaging-excludes oxygen, builds up CO2 |
|
post-harvest factors affecting quality of fruit
|
moisture loss
exposure to oxygen bruising time before processing processing: cutting, peeling, washing |
|
enzymatic browning reaction
|
polyphenols + O2 -phenolase-> quinones + H2O -polymerization-> brown pigments
|
|
preventing enzymatic browning
|
avoid oxygen-required as substrate
add salt-Cl ion interferes with enzyme keep product cool-inhibits enzyme alter pH-inhibits enzyme blanch-heat inactivates enzyme add reducing agent-reverses reaction |
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leaves
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lettuce, cabbage
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seeds
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peas, beans, corn
|
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roots
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carrots, rutabaga
|
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tubers
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short, thickened fleshy part of an underground stem
irish potato, jerusalem artichoke |
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bulb
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onion, garlic
|
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flowers
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broccoli, cauliflower
|
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fruit (part of vegetables)
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cucumber, okra, squash
|
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stem or shoot
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celery, asparagus
|
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RH
|
Relative humidity
|
|
raw vegetable short term storage
leafy vegetables |
water vapor resistant packaging
|
|
raw vegetable short term storage
carrots, cabbage |
32F
90-95% RH |
|
raw vegetable short term storage
avocados |
40-56F
|
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raw vegetable short term storage
potatoes |
55F, high RH, dark
|
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substrate
|
acted on by enzyme
|
|
compartmentation
|
enzyme and substrate-disrupted cells- enzyme and substrate mix-product
|
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effects of cooking vegetables on flavor/odor
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mild vegetables-minimal water to retain flavor
stronger vegetables-want weaker odor/flavor cook long without lid, want strong flavor cook in little water with lid |
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effects of cooking vegetables on texture
|
during cooking, texture softens
-determines doneness -can be bad if too soft--mushy |
|
firming effect of calcium
|
pectin associates through a salt bridge
|
|
waxy texture
|
translucent appearance
pasty and wet |
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mealy texture
|
glisteny appearance
feels granular and dry in mouth mashed/baked potato |
|
specific gravity indication of texture
|
floaters-waxy, sinkers-mealy
|
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loss of minerals from vegetables
|
leaching into water
paring-trimming, removing peel |
|
loss of vitamins from vegetables
|
leaching
paring heat (hastens chemical reaction) air (oxidation) enzymes (oxidation) |
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ice cream def
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10% milk fat, non milk fat solids
|
|
soft serve
|
ice cream mixture before it leaves freezer, 30-60% frozen
|
|
frozen yogurt
|
cultured product frozen with sugars, flavors
|
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steps in making ice cream
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blending
pasteurization homogenization aging mix freezing to soft serve packaging hardening |
|
pasteurization
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heats to destroy pathogens
|
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homogenization
|
reduces fat, suspension to a colloid
|
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function in ice cream
sugar |
flavor, lowers freezing point
|
|
function in ice cream
milk fat |
finer texture, interferes
smoother texture-lubrication |
|
nonfat milk solids
function in ice cream |
increases viscosity
incorporates air bubbles |
|
emulsifier
function in ice cream |
air incorporation, disperses fat
stiffer, dryer |
|
stabilizer
function in ice cream |
stops ice crystals growing by binding water, smoothness
|
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freezing rate on ice crystal formation
|
faster freezing rate, greater number and smaller size of ice crystals
|
|
temperature fluctuations on ice crystals
|
larger, fewer ice crystals
|