1-lipid

Question 1

difference btw fat and oil?

Answer 1

different in melting point: fat has high melting point while oil has low MP and is liquid in room T.

Question 2

Is wax a fat?

Answer 2

No, wax is FA esterified with an alcohol.

Question 3

which category does jojoba oil and bee’s wax belong to?

Answer 3

Wax

Question 4

Liquid or solid? Jojoba oil and bee’s wax?

Answer 4

jojoba oil: liquid at room T

Bee’s wax: solid wax

Question 5

what is application use for wax for food use?

Answer 5

cheese—sealing agent

apple—–polishing agent

Question 6

How does wax being used in the market？

Answer 6

Cosmetics (monounsaturate long chain FA)

in FOOD: low-calorie food ingredient

Question 7

Which category does cholesterol ester belong to?

Answer 7

Wax.

FA esterified to a complex alcohol

Question 8

Give an example of FA esterified to a complex alcohol?

Answer 8

VA/retinol

cholesterol ester

Question 9

Is wax biologically active?

Answer 9

yes

Question 10

what is compound lipid?

Answer 10

simple lipid conjugated with non-lipid molecule.

Question 11

Give examples of compound lipids?

Answer 11

phospholipid, sphingolpid/ glycolipid, lipoprotein.

Question 12

How is phospholipid differ from triacylglyceral?

Answer 12

TAG: glycerol attached to 3 FA
Phospholipid: glycerol attached to 2 FA + 1 phosphate

Question 13

What is phosphoric acid?

Answer 13

phosphate group attached to the glycerol backbone

Question 14

What is a phosphatidic acid?

Answer 14

is the base structure of non-lipid moiety
when X=OH.
X=nitrogenous base when it is a phospholipid.

Question 15

what is the proportion of phospholipid comprised in the lipid material that found in food system?

Answer 15

5%

Question 16

Is phospholipid amphipathic?

Answer 16

Yes. both hydrophobic and hydrophilic

Question 17

what property does phospholipid has?

Answer 17

emulsifying property / emulsifier

Question 18

Classes of phospholipid?

Answer 18

• lecithin (phosphatidyl choline)
• cephalin (phosphatidyl ethanolamine)
• phosphatidyl inositol
• phosphatidyl serine

Question 19

which group does cardiolipin belong to? Food sourse?

Answer 19

diphosphatidyl glycerol.

found in beef heart

Question 20

where does glycolipid found?

Answer 20

In membrane lipid of plants and animals

Question 21

Give an example of food source of lipoprotein?

Answer 21

Egg

Question 22

Is HDL good for the body？Why?

Answer 22

yes, it accounts for 1/3 all blood-circulating chol and serve as protective mechanism for heart disease by carrying away chol from vessel walls and plaque to the liver for disposal.

Question 23

Is LDL neede in the body? WHY?

Answer 23

Yes, because it transport substances vital to cell function and development.

Question 24

why LDL bad for body?

Answer 24

when LDL is in excess in the blood, it can change its structure from body stress. when it accumulates in the blood vessel walls, they can lead to blockage in artery / unstable plaque build up which is prone to rupture and formation of blood clots.

Question 25

what is derived lipid?

Answer 25

Derived from simple/ compound class.

Question 26

Class of derived lipid?

Answer 26

Fatty acid, fatty alcohol, hydrocarbons (ex. oxygenated derivatives)

Question 27

how does short chain fatty acid important in the food system?

Answer 27

It can be used as flavor compounds.

Question 28

Can long chain free fatty acid be used as flavor compound? What can it be used as?

Answer 28

no.

• it can be used in the presence of mineral salts (soapy flavor)
• it can used for edible oil by lowering the smoke point for frying

Question 29

how can short chain alcohol be used? (derived lipid)

Answer 29

Contribute to flavor

Question 30

give an example of unsaturated hydrocarbon?

Answer 30

terpene (built from isoprene unit)

Question 31

what is the main component of essential oil?

Answer 31

terpene (monoterpene + sesquiterpene)

Question 32

Use of lipid?

Answer 32

serve as fuel; emulsifier; give creamy mouthfeel; solubilize many taste and aroma constituent of food; give desired texture;

Question 33

what class of lipid is of majority of the food system?

Answer 33

fats (95-96%) + phospholipid

Question 34

when a scientist refer to LIPIDS, what compound does he want to mention?

Answer 34

Triglyceride.