Week6

Question 1

T or F : when the FA undergo hydrogenation, the configuration necessarily change from cis to trans

Answer 1

no, not automatically

Question 2

What are the functional properties of fats and oils in food? (7)

Answer 2

1. Heat transfer agent
2. tenderize baked products
3. Lubricating agents
4. Aeration
5. Enhance flavors
6. Contribute to texture and mouthfeel
7. Feeling of satiety

Question 3

What causes the flakiness in baked product containing a lot of FATS?

Answer 3

The chewiness is caused by protein strands in flour and FATS cut the protein strands.

Question 4

What determine the flakiness?

Answer 4

Fat to flour ratio

Question 5

How does lipids create aeration in food products?

Answer 5

They both are hydrophobic so fat can retain water bubbles in a batter.

Question 6

T or F : fats and oils don’t have flavors on their own but they enhance flavors by dispersing flavor compounds

Answer 6

T

Question 7

What is the major factor that has an impact on the functionality of fat

Answer 7

the degree of plasticity. (determined by the SFC that depends on the lipid profile)

Question 8

Below the melting point, the lipid is ____

Answer 8

solid fat

Question 9

What is the solid fat content ?

Answer 9

SFC is the state of solid fat and liquid oil that happens to lipid in a certain temperature range around the melting point.

Question 10

Complete : olestra is a ____

Answer 10

sugar polyester

Question 11

What are the two types of deteriorative reactions that can happen to fats and oils?

Answer 11

1. Enzymatic rancidity

2. Oxidative rancidity

Question 12

What is autoxidation?

Answer 12

The normal saturation of the double bonds of fat and lipids that happens over time with O2

Question 13

What are the factors that influence the autoxidation?

Answer 13

1-High RH
2-light
3-metallic ions
4-heat

Question 14

Complete : The rate of autoxidation is very slow for____ but

increases exponentially with increasing number of ____

Answer 14

Saturated fats

Double bonds

Question 15

What can you do to a fat/oil mixture to reduce the autoxidation

Answer 15

1. Antioxidants like vitamin E

2. hydrogenate the fat (decrease double bonds number)

Question 16

What is rancidity?

Answer 16

The loss of quality of oil that occur with time (deterioative reaction) and results in unpleasant odors and tastes

Question 17

What is lipolysis?

Answer 17

A kind of deteriorative reaction that occurat high temperature and in the presence of water that gives free FA and glycerol by the enzymes found in plants and oils

Question 18

T or F : lipolysis and autoxidation in oils are bad for the health

Answer 18

False, lipolysis is not bad for the health but if the free FA content is higher than 1% the oil is non-consumable

Question 19

T or F : lipolysis and autoxidation occurs when frying food

Answer 19

True in the case of autoxidation because of high temperature and presence of oxygene and in the case of lipolysis because of high temperature and the presence of water

Question 20

What is the smoke point?

Answer 20

The temperature at wich fatty acid break appart and produce smoke. You also need to change the frying oil if the temperature went at the smoke point

Question 21

What is the flash point?

Answer 21

The temperature at wich the lipids flame

Question 22

What can you determine about a solution when you know its smoking point?

Answer 22

The degree of enzymatic or lipolysis that has occured in the sample

Question 23

T or F : when choosing a frying oil, it is better that you choose a oil that is rich in free FA

Answer 23

False, because it will reduce the smoke point of an oil and you will need to discard it at much lower temperatures

Question 24

What part of the pospholipid molecule can change and will dictate the type of phospholipid

Answer 24

The nitrogen based attached to the phosphate group at the C3 of glycerol

Question 25

T or F : A phospholipid is a glycerol base with 2 fatty acids and a
phosphorus-containing acid attached

Answer 25

T

Question 26

T or F : the flash point can be used to determine the degree of lipolysis that has occurred in a fat/oil sample

Answer 26

F, is is the smoke point (the T at which the FFA produce smoke)

Question 27

Lower is the smoke point and ____ is the free fatty acid content of a sample

Answer 27

higher