Technical challenges : part I : proteins

Question 1

What are the two categories of food ingredients ?

Answer 1

1. macrocomponents

2, microcomponents

Question 2

What is a food additive?

Answer 2

is any chemical substance that is added to food during the preparation or storage and either becomes a partof the food or affects its caracteristics.

Question 3

Does sugar and salt, starches are considered as food additives?

Answer 3

no

Question 4

Are vitamins added for technofunctional properties considered as food additives?

Answer 4

yes

Question 5

Are spices, seasonings, flavoring preparations are considered as food additives?

Answer 5

no

Question 6

What is the functionality of an ingredient ?

Answer 6

any property of a food ingredient that affects its utilization (not its nutritional value).

Question 7

True or false : the functionality can refer to the nutritonal value of a food?

Answer 7

false

Question 8

What are the basics guideline we can refer to for the selection of ingredients?

Answer 8

1- routine 
2- taste
3- functionality 
4- stability
5- form and effects

Question 9

what is the name of the mycoprotein based meat alternative?

Answer 9

fusarium venetatum

Question 10

is there a way to imitate the texture of meat in vegetable based products

Answer 10

with extrusion technology you can make texturized vegetable proteins

Question 11

What will give the proteins its functions?

Answer 11

1- a.a. composition
2- the primary structure
3. the secondary structure

Question 12

Why is the environment of protein particularly important?

Answer 12

because it will affect the technofunctionnality of the proteins as an ingredient

Question 13

what are the functional properties of proteins?

Answer 13

1- coagulation
2- gelation
3- structure formation 
4- emulsification 
5- water holding capacity 
6- foam formation
7- fiber formation 
8- fat absorption

Question 14

With a pH ____ from the isoelectric point, the wheat proteins tends to have more extensible properties

Answer 14

away

Question 15

What are the two properties when dealing with wheat proteins?

Answer 15

1. extensibility

2. elasticity

Question 16

What is elasticity ?

Answer 16

the deformation
reversbility under stress
providing more strenght ot the dought

Question 17

What is the extensibility

Answer 17

1. flexibility
2. elongation
3. provides more tenderness

Question 18

The wheat proteins near their isoelectric point will have more ___

Answer 18

strength (elasticity)

Question 19

The elasticity will provide more ____ and the ____ will provide more tenderness

Answer 19

elasticity : strenght

extensibility : tenderness

Question 20

For muffin and bakery, you want to favor the ____

Answer 20

extensibility

Question 21

when you are dealing with the bread you’l want to favor the ___

Answer 21

elasticity

Question 22

So if you isolate the wheat proteins near the isoelectric point, then you’,ll favor the ____

Answer 22

elasticity

Question 23

If you isolate far from the isoelectric point the protein you”ll favor the ____

Answer 23

extensibility

Question 24

_____ can be added to make it more softer and

high elasticity.

Answer 24

cystein

Question 25

why is cystein added to flour?

Answer 25

to make a dough more extensible by breaking the sulfhydrate groups between proteins

Question 26

T or F : denaturation is always bad in the case of protiens

Answer 26

false, in the case of gelation, you need to have denaturation to have a gel so it can be gppd.

Question 27

Give examples of food that are gel

Answer 27

hot dogs, yogourt, custard

Question 28

***so if I ask you what determine the rheologicl properties of my gel what is the answer ?

Answer 28

the ratio of protein-protein interaction and protein-water interaction. more protein-protein interaction and cross-linking the gel is strong and if more protein-waater you have a loose gel

Question 29

What are the three events that can be identified in the protein gelation process?

Answer 29

1. denaturation 2. aggregation 3. crosslinking

Question 30

The gelling ability of protein is influenced by : (4)

Answer 30

1. molecular weight 2. a.a composition 3. hydrophobicity 4. protein concentration

Question 31

the development of a 3D network during gel formation is influenced by :

Answer 31

1. method of prepation 2. processing conditions 3. environment factors sucj as pH and ionic strenght

Question 32

Gels formed at the isoelectric point are less ____ and ___ because of the lack of

Answer 32

firm and hydrated | lack of repulsive force

Question 33

What is the definition of the water holding capacity

Answer 33

The water holding capacity of foods can be defined as the ability tohold its own and added water during the formulation andthe application of forces, pressing, centrifugation or heating.

Question 34

what is the difference between the swelling and the water holding capacity ?

Answer 34

the swellin is the first step in the solvation and can be definied as a spontanenous uptake of water by protein matix.

Question 35

Water holding capacity is important for the ____

Answer 35

mouthfeel of the product, texture, taste and tenderness

Question 36

Water holding capacities are important to prevent ___

Answer 36

synerisis

Question 37

What is the swelling capacity?

Answer 37

The first step in the solvation of proteins and can be defined as the spontaneous uptake of water by a protein matrix.

Question 38

T or F : you can have proteins with the same swelling and not the same WHC

Answer 38

T

Question 39

T or F : You can have proteins with different swelling and the same WHC

Answer 39

T

Question 40

as we increase the temperautre, we ___ de WHC

Answer 40

decrease because of the exposition of hydrophobic amino acids

Question 41

What are the factors that will influence the WHC

Answer 41

1. protein concentration 2. pH 3. ionic strenght 4. temperature 5. presence of other components 6. lenght of heat treatment and storage conditions

Question 42

What are the two type of emulsifier we saw in class

Answer 42

1. small molecular weight surfactants | 2. proteins/polysaccharides

Question 43

What are small molecular weight surfactants

Answer 43

the small molecules has a high | ability to reduce the interfacial tensions because they can migrate really quickly and go reduce the surface tension.

Question 44

What are the protein/polysaccharide emulsifiers ?

Answer 44

the more big molecules like proteins and polysaccharides they can form a continous and viscoelastic membrane like film around of droplets and that will lead to stable emulsion.

Question 45

The caracteristic used to describ the emulsifying properties of proteins are :

Answer 45

1- emulsifying capacity (EC) 2- Emulsifying stability (ES) 3- Emulsifying index (EA m^2/g)

Question 46

What is the emulsifying capacity (EC) ?

Answer 46

The amount of oil (ml) that is emulsified under spectific conditions by 1 g of protein

Question 47

What is the ES ?

Answer 47

emulsifying stability : the capacity of emulsions droplets to remain disperesed without separation by creaming, coalescing, or flocullation.

Question 48

What are the 3 types of emulsion instability ?

Answer 48

1. creaming 2. coalescence 3. flocculation

Question 49

How can we measure the emulsifiation properties?

Answer 49

HLB = weight of hydrophilic / weifght of total * 100 / 5

Question 50

What is foaming ?

Answer 50

the creation and stabilization of gas bubbles in a liquid.

Question 51

What are example of product that are foam based

Answer 51

1- icecream 2- souffle 3- sponge cake 4-meringue

Question 52

The foaming capacity of the protein are often expressed as ____

Answer 52

overrun

Question 53

what is the formula of overrun

Answer 53

overrun = ( volume of foam - volume of initial liquid / volume of intial liquid ) * 100

Question 54

the overun will tell us :

Answer 54

how much of foam is going to be in the product as compared to the volume initial

Question 55

Foam stability is often expressed as :

Answer 55

the time required for 50%of the liquid to drain from a foam or for a 50% reduction in foamvolume.

Question 56

``` A unique class of proteins produced by filamentous fungi (Trichoderma reesei), possessing remarkable interfacial and foam stabilizing properties, are known as ___ ```

Answer 56

hydrophobins

Question 57

Why are the protein bar often flavorless?

Answer 57

because protein can bind flavors up to a certain amount and will be critical to the flavor delivery

Question 58

Below the critical concentration a protein might form a ___ instead of a ___

Answer 58

viscosity | gel