Unit 5 Flashcards
3 groups of fats
triglycerides
phospholipids
sterols
What is the most common form of fat
triglycerides
True or false: each species makes its own characteristic type of triglyceride
True
True or false: fats in the diet can affect the type of triglyceride made
True
Fatty acids are classified by (2)
Chain length
degree of saturation (double bonds)
FA lengths:
short =
medium =
long =
2-4
6-10
12+
(shorter/longer) chain FA tend to be softer and melt easier
shorter
True or false: most fatty acids have an odd number of carbon atoms
false
Higher saturation in FA means more or less H atoms attached?
more
the more unsaturated the fat, the more (liquid/solid) it tends to be at room temp
liquid
Vegetable and fish oils are rich in (mono/poly) unsaturated FA
poly
tropical oils (coconut) are (low/high) in unsaturated FA but (low/high) in saturated FA
low in unsaturated
high in saturated
Are plant or animal fats generally more saturated
Animal
Butyric acid is found in what
Butter
Stearic acid is found in what
Beef
Palmitic acid is found in what
palm oil and cocoa butter
Number of carbon atoms in: Butyric acid Palmitic acid Stearic acid Oleic acid Linoleic acid Linolenic acid
4 16 18 18 18 18
Number of double bonds in: Butyric acid Palmitic acid Stearic acid Oleic acid Linoleic acid Linolenic acid
0 0 0 1 2 3
Oleic acid is found in what types of oil
Olive and canola
Linoleic acid is found in what types of oil
canola and soybean
Linolenic acid is found in what types of oil
soybean and hempseed
True or false: unsaturated FA are always in cis form
false, can be cis or trans
What has a higher melting point, cis or trans FA
trans
True or false: Trans FA are man made
false, can be found naturally in meats and milk
What process creates trans FA
hydrogenation
What is hydrogenation
hydrogen is added to unsaturated FA
True or false: points of unsaturation are more vulnerable to oxidation
True
Oxidation of fats causes ____
rancidity
True or false: once hydrogenated, unsaturated FA lose their health benefits
True
True or false: Hydrogenation does not affect vitamins
False
What is the structural difference between triglycerides and phospholipids
triglycerides have 3 FA chains
phospholipids have 2 FA chains
What molecule on the phospholipid structure makes it soluble in water
phosphorus
phospholipids are emulsifiers, meaning ___
they keep fats dispersed in water (i.e. mixed together)
Lecithin is a _____ found in what food
phospholipid
egg yolk
What are sterols
large molecules made of interconnecting rings of carbon atoms with organic side chains (C,H,O)
Cholesterol is an example of a _____
sterol
The raw material in bile is ___
cholesterol
Cholesterol is important for ____ digestion
fat
The major part of plaques in arteries is what molecule
cholesterol
Is cholesterol an essential or non-essential nutrient
non-essential
Instead of cholesterol, plants make what sterol
phytosterols
True or false: Phytosterols interfere with the absorption of cholesterol
True
Vitamin D is an example of a _____
sterol
Cholesterol is a precursor for _____
sex and stress hormones
What is the winterization of fats
a process to produce salad oils that do not crystallize at cold temps
How does winterization of fats work
lower oil temp until triglycerides start to crystallize, and then filter them off. Whats left will be those with lower melting points
What 3 factors increase chances of rancidity
heat
oxygen
light
What is more susceptible to rancidity, unsaturated or saturated fats
unsaturated
name 3 foods that easily go rancid
nuts
wheat germ
whole wheat flour
what are the 2 types of rancidity
- Oxidative rancidity
2. Hydrolytic rancidity
Oxidative rancidity occurs most in ___
unsaturated FA
oxidative rancidity involves formation of ____
Hydroperoxide
Oxidative damage can be slowed by the use of ____
antioxidants
Hydrolytic rancidity involves addition of ___
water and enzyme activity
Hydrolytic rancidity involves formation of ____ and ____
glycerol and free short chain FA
What is a catalyst for hydrolytic rancidity
heat
What are fat replacers
ingredients that replace some or all of the functions of fat and may or may not provide energy
What are artificial fats
zero-energy fat replacers (resistant to digestion)
carbohydrate based fat replacers provide similar ____ to fats but do not ____ like fats
mouthfeel
taste
True or false: carbohydrate fat replacers cannot be used in frying
True
Protein based fat replacers are blended with ___ to form gels
gums
protein based fat replacers are often used in what type of foods
frozen and refrigerated dairy products
True or false: protein fat replacers cannot be used in frying
True
fat based fat replacers are made with fewer _____
carbon molecules (i.e. shorter FA chains)
long chain FA + sucrose =
sucrose polyester
Linoleic acid, linolenic acid are which types of FA
linoleic acid = omega 6 FA
linolenic acid = omega 3 FA
What are the only essential FA
linoleic and linolenic acid
What are eicosanoids, what are they made from?
biologically active compounds that regulate body functions
essential FAs
Foods containing omega 6 FA
veggie oils, nuts, seeds, whole grains
Foods containing omega 3 FA
flax, canola, fish
Should you consume more omega 3 or 6 FA?
omega 3
What are the 3 main types of omega 3 FA and where are they from?
ALA - plants
EPA - fish
DHA - fish
True or false: Fish found in fast food and frozen products tend to be species with lower DHA/EPA content
True
Fish oils tend to have high concentrations of which vitamins
A and D
What is the difference between regular and conjugated linoleic acid
regular = 2 double bonds separated by 2 single bonds conjugated = 2 double bonds separated by 1 single bond
In what foods is CLA found
animal products such as milk and meat
Which animals contain more CLA:
cows, chicken, turkey, sheep, pork
cows and sheep
What elements make up protein
C, H, O, N
Electric charge of an amino acid is determined by ___
the side chain
Globular amino acids are (soluble/insoluble) in water
soluble
Fibrous amino acids are (soluble/insoluble) in water
insoluble
explain the following stages of protein structure:
- primary
- secondary
- tertiary
- quaternary
primary = linear sequence of amino acids secondary = alpha helix or beta sheet tertiary = 3D shape, folded quaternary = globular proteins (multiple proteins)
True or false: plant based proteins are higher quality than meat proteins
false
True or false: legume proteins are more easily digested than plant/grain proteins
true
What cooking method most improves and hinders protein digestibility
wet heat improves
broiling (dry heat) hinders
what is protein complementation
combining 2+ plant sources to provide a more complete array of amino acids
The more charged the AA, the greater the ____ capacity
hydration
what are food foams
gas dispersed within a liquid
bromeliad and papain are enzymes used for ___
meat tenderizer
rennin or chymosin are enzymes used for ___
clotting of milk
3 methods to prevent browning
denature the enzyme with heat
cover to protect from O
adding ascorbic acid (vitamin C)
what are the 2 forms of non-enzymatic browning
Caramelization
Maillard reaction
What is the beginning and end stage of caramelization
dehydration
polymerization
What is the average temp needed for caramelization
200 degrees
The darker the caramel, the less/more sweet it is
less
What is the maillard reaction
reaction between the carbonyl group of carbs and the amine group of proteins at high temp