lipids

methyl group

-CH3

essential fatty acids are essential for

-forming vital body structures -in immune system function -in function -forming cell membranes

negative health consequences of saturated fats

-increase in plaque buildup in the arteries -increase in LDL cholesterol -increase in risk of heart disease & stroke

why are oils hydrogenated

-makes them more solid or film -longer shelf life (unsaturated fats go bad quickly) -once believed to be healthier than animal fats b/c they come from plant oils

benefits of essential fatty acids

-omega-3 fatty acids can lower blood triglycerides & slow growth of plaque on the arteries -disease risk of hypertension, heart disease, and diabetes

trouble with trans fats

-raise LDL cholesterol & lower hDL cholesterol -raise risk of disease even more than saturated fats

health benefits of coconut oil despite its high saturated fat content

-raises HDL cholesterol -medium length chain triglycerides do not get turned into body fat -good for brain health -helps burn body fat

why does hydrogenation result in a mixture of saturated & trans fat

-turns double bonds to singles -switches some hydrogen atoms to the other side of the molecule

triglycerides are composed of what

3 fatty acids & a glycerol backbone

medium chain

6-10 carbon atoms

carboxyl group

COOH

unsaturated fatty acid shape

a bend or "kink" in the shape - more double bonds = more bends

emulsion

a mixture of two liquid phases that don't normally mix

functions of fat in food

adds flavor in food, creates a rich, creamy mouthfeel, shorten baked goods, & aeration

phospholipids as emulsifiers

because they have hydrophobic & hydrophilic portions, phospholipids can coat the oil to suspend it in water

does shortening or butter melt faster?

butter

does shortening or butter make a chewier cookie?

butter - contains 20% of water which helps gluten formation

examples of sterols

cholesterol and vitamin d

phospholipids

compounds consisting of a glycerol backbone with two fatty acids and one phosphate-containing group

examples of polyunsaturated fats

corn oil, safflower oil, soybean oil, sunflower oil, and fish oils

low smoke point oils

dips and dressings

sesame oil

distinct nutty flavor

lipases

fat-specific enzymes that assist in the breaking down of triglycerides

what part of the phospholipid is hydrophobic?

fatty acid "tail" - face towards oil

omega-3

fatty acids that have the first double bond on the 3rd carbon from the omega end

omega-6

first double bond on the 6th carbon from the omega end

omega-9

first double bond on the 9th carbon from the omega end

sources of omega-3 fatty acids

fish, fish oil capsules, walnuts, flax seeds, or chia seeds

smoke point - chemical composition will change altering what

flavor

what part of the phospholipid is hydrophilic

glycerol & phosphate "head" - face towards water

medium smoke point oils

good for baking or stir-frying

saturated fatty acids

have all single bonds between carbon atoms

unsaturated fatty acids

have at least one double bond between carbon atoms

polyunsaturated fatty acids

have multiple double bonds

monounsaturated fatty acids

have one double bond

trans- configuration

hydrogen atoms are on opposite sides of the double bond (straight-chain shape similar to saturated fats)

cis- configuration

hydrogen atoms are on the same side the double bond (bent shape)

how are triglycerides broken down

hydrolysis

why are unsaturated fats liquids (oil) at roomp temp

kinked structure does not allow molecules to pack together tightly

triglycerides can vary in

length, saturation, and location of double bonds

short chain

less than 6 carbons

phospholipid function

make up cell membranes, act as emulsifiers to keep fats suspended in solution

long chain

more than 12 carbons

where do saturated fats come from

most come from animal sources (lard, butter, beef tallow) & some come from plant sources (palm oil, coconut oil)

canola, safflower, corn oil

neutral flavor

what do USDA dietary guidelines recommend for saturated fats

no more than 10% of calories (200 per day) should come from saturated fats

hydrophobic

not soluble in water

olive oil

olive flavor good for salad dressings or dips

examples of monounsaturated fats

olive oil, canola oil, avocado

essential fatty acids

omega-3 & omega-6

lipids

organic compounds composers of carbon, hydrogen, and oxygen that are insoluble in water

why are omega-3 & omega-6 fatty acids essential

our body doesn't manufacture them so they are supplied from our diet

lecithin

phospholipid found in eggs

where can omega-6 essential fatty acids be found

plant oils

fats are used in frying to

prevent sticking to the pan, transfer heart, produce characteristic flavor of the fat when heated

hydrophilic

soluble in water

sources of omega-6 fatty acids

soybean oil & other vegetable oils, nuts, eggs, chicken

saturated fatty acid shape

straight-chain

mono & diglycerides

synthetically made phospholipids

are trans fatty acids unsaturated or saturated?

technically unsaturated but have the properties of a saturated fat

why are saturated fats solids at room temp

the straight-chain fatty acids pack together to make a solid

smoke points

the temperature at which an oil starts to smoke and break down into free fatty acids

shortening

to create a crumbly, flakey texture

aeration

traps air to add to fluffy texture

types of lipids

triglycerides (fat/oil), phospholipids, sterols

unsaturated fats

triglycerides high in fatty acids with at least one double bond

saturated fats

triglycerides high in saturated fatty acids

coconut oil

tropical flavor

considerations of fat food for cooking

usage: frying vs fresh, cooking duration & temp, taste & flavor

high smoke point oils

used for searing, browning, or deep frying

cholesterol

used to make hormones and vitamin d

examples of hydrogenated oils

vegetable shortening (crisco) & margarine

sterols

waxy compounds that are insoluble in water & have structures with carbon rings

hydrogenation

when hydrogen is added to an unsaturated fat at high pressure