Week 4- Good Copy Flashcards
What are lipids?
a family of organic compounds that are not soluble in water
what are the 3 types of lipids?
- triglycerides (fats and oils)
- phospholipids (ex. lecithin)
- sterols (cholesterol)
What are the key functions of fats in the body?
- chief storage form for excess food energy (survival during feast or famine)
- energy for body’s work
- shock absorbers
- thermoregulation
- cell membranes
- needed nutrients
- aids in absoprtion of phytochemicals
- essential fatty acids
- energy density can be helpful
- contributes to satiety (feeling full)
What type of tissue is adipose tissue?
active fat tissue
Role of adipose tissue?
FAT CELLS. secretes hormones, expand and multiply, produces enzymes that influence food intake, and affect the body’s use of nutrients
What is the structure of tryglycerides?
3 fatty acids and glycerol
What are fatty acids?
organic acids composed of carbon chains of various lengths, each has an acid end with hydrogens attached to all carbon atoms on the chain. differs in length and degree of saturation
What is the role of glycerol in terms of tryglcerides?
serves as the backbone
What is the difference between MUFA and PUFA (also what are the two terms)?
- MUFA: monounsaturated fatty acid
- PUFA: polyunsaturated fatty acid
MUFA only has one carbon-carbon double bond, PUFA has more than one. This is what the “Degree of saturation” is.
What does it mean for the melting temperature if the fatty is unsaturated?
the more unsaturated the fatty acid, the more liquid the fat is at room temperature (ex. sunflower oil)
the more saturated the fatty acid, the firmer it is at room temp (ex. lard)
What is the most common fatty acid chain length in the diet?
12-24
What are medium chain fatty acid chains? what about short chains? Where are these found
medium: 6-10 carbons
short: less than 6 carbons
dairy products
True or False: triglycerides are usually only composed of one type of fatty acid.
FALSE
usually include a mixture of fatty acids
Length of carbon chain: increases or decreases with decreased firmness
shorter the carbon chain length, the decreased firmness
Why are saturated plant oils like cocoa butter and palm oil softer than animal fats?
- palm oil and cocoa have 12 carbons or shorter
- beef fat is maonly made of 18 carbons in length
What is the health recommendation when referring to saturated and unsaturated fats?
- limit saturated fats
- limit or avoid trans fats
- the harder the fat, the poorer the choice
- use monounsaturated fats or polyunsaturated fats instead
What types of oils are usually rich in polyunsaturated fatty acids?
- vegetable oils (safflower, sunflower, corn oil)
- fish oils
What vegetable oil is rich in monounsaturated fatty acids?
olive oil
which fats were usually the most saturated?
- animals fats
- tropical fats
- fatty meats: over 1/3 of fat in most meats is saturated
- whole milk products: over 1/2 of fat in whole milk is saturated (and other high fat dairy products)
- cocunut and palm oils (commerically prepared foods)
True or false: there is a benefit to cardiovascular risk when monounsaturared or polyunsaturated fats are used to replace saturated and trans fats in diet?
true
What is the connection between olive oil and health?
- rich in monounsaturated fatty acids
- evidence from mediterranean diet
- olive oil offers a degree of protection against heart disease when used in place of other fats
- dark colored olive oil means more phytochemicals
What is the oil that is the lowest in saturated fat?
canola oil, rich in both monounsaturated and polyunsaturated fatty acids
What is hydrogenation?
a chemical process by which hydrogens are added to monounsaturated or poluunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated (solid) and more resistent to oxidation
How are trans fatty acids formed?
- polyunsaturated fat is rarely hydrogenated completely during processing
- some double bonds remain
- double bonds change from the cis to trans formation
Where are naturally occuring trans fat usually occur?
milk and meat products
What is the disease reduction claim regarding saturated and trans fats?
a healthy diet low in saturated and trans fats may reduce the risk of heart disease
What are the advantages of hydrogenation and the commerical benefit?
- Protect against oxidation by making polyunsaturated fats more saturated
- commerical: increase shelf life - alter the texture of food by making liquid veggie oils more solid
- improve food texture
- hydrogented oil has higher smoking point
- more stable in high cooking temperatures
What are alternatives to hydrogenation?
- add BHA and BHT to react with oxygen before it can do damage
- keep refrigerated
True or False: it is now illegal for manufacturers to add PHOs (partially hydrogenated oils) to foods sold in canada
True
What is the structure of phospholipids?
2 fatty acids, glycerol, and a phosphorus containing molecule
Fatty acid is soluble in what? phosphorus is soluble in what?
fatty acid: fat
phosphorus: water
What does it mean that phospholipids are “emulsifiers”?
one end interacts with oil, while the other end with water.
it is a substance that mixes with both and water and disperses the fat in the water
What is something that has lecithin (phospholipid)?
mayo
Do Lecithin supplements benefit health?
- no
- body makes all if tneeds
*
Where is lecithin found?
eggs and peanuts
What are sterols (and their basic structure)?
large molecules consisting of interconnected rings of carbon atoms with side chains of carbon, hydrogen and ozygen
Where are steros found? What are the two types found?
present in foods derives from both plants and animals
* cholesterol: derived from animals
* phytosterols (plant sterols: plant derived compound, similar structure to cholesterol