FOODEMULSIFIERS

Question 1

Surfactants (surface-active agents) are molecules that

Answer 1

migrate to the interface between two phases

Question 2

FUNCTIONS OF EMULSIFIER: facilitate formation of

Answer 2

smaller oil droplets during emulsification process

Question 3

FUNCTIONS OF EMULSIFIER: stabilising

Answer 3

the emulsion once it has formed

Question 4

1) FACILITATE FORMATION OF EMULSION with high

Answer 4

interfacial tension at an oil-water interface

Question 5

Emulsifiers adsorb

Answer 5

onto the interface during emulsification

Question 6

Reduce the interfacial tension and increase

Answer 6

interfacial area between oil &water

Question 7

2) Emulsifiers stabilize emulsions by accumulating

Answer 7

at the interface of the two phases where they
form a barrier that prevents the droplets of the discontinuous phase from coalescing

Question 8

Amphoteric: hv both

Answer 8

positively and negatively charged ions

Question 9

Emulsifiers that are easily soluble in water (more hydrophilic)

Answer 9

produce o/w emulsions.

Question 10

The emulsifier interacts strongly with the water

Answer 10

reducing the surface tension of the water
approaches zero

Question 11

Lipophilic emulsifiers are not water-soluble and

Answer 11

interact with the oil phase

Question 12

the surface tension of the water is not
significantly reduced so

Answer 12

it remains as discrete droplets in the oil,
producing a w/o emulsion

Question 13

3 classifications of emulsifiers based on their molecular weight

Answer 13

solid, high, low

Question 14

solid

Answer 14

stabilize oil droplets in emulsions through adsorption at the interface (eg starch nanocrystals)

Question 15

High molecular weight

Answer 15

Contain both hydrophobic and
hydrophilic moieties in their
polymer chain (eg protein, gum arabic, certain pectins)

Question 16

Low molecular weight

Answer 16

Have hydrophilic head & hydrophobic tail (lecithin)

Question 17

SYNTHETIC EMULSIFIERS are made from

Answer 17

fats, oils, glycerols, organic acids,

Question 18

Monoglycerides as synthetic emulsifiers

Answer 18

produced by esterification or alcoholysis of edible fats and oils or fatty acid with glycerol in the presence of a catalyst

Question 19

NATURAL EMULSIFIERS

Answer 19

• Polysaccharide
• Protein-based

Question 20

Many proteins are surface active because

Answer 20

they contain a mixture of hydrophilic and hydrophobic amino acids along their polypeptide chains.

Question 21

protein can adsorb….. and coat…..

Answer 21

adsorb to oil–water interfaces and coat the oil droplets formed during homogenization

Question 22

protein Stabilize droplets from aggregation by

Answer 22

electrostatic repulsion [negative (COO−) or positive(NH3+)charges] & steric repulsion (thick layer)

Question 23

eg of protein emulsifier

Answer 23

Caseins , whey proteins (a-lactalbumin, b-lactoglobulin, immunoglobulins), gelatin, soy proteins, and pea proteins

Question 24

Most polysaccharides are

Answer 24

highly hydrophilic molecules that are not particularly surface-active, and are therefore not good emulsifiers

Question 25

Polysaccharides tend to stabilize

Answer 25

emulsions by increasing aqueous phase viscosity and thereby inhibiting droplet movement

Question 26

A number of natural or modified polysaccharides have hydrophobic groups

Answer 26

attached to a hydrophilic chain

Question 27

Phospholipids are derived from

Answer 27

the cell membranes of plant, animal, or microbial tissues.

Question 28

The phospholipids used in food and beverage applications are usually referred to

Answer 28

as lecithins

Question 29

An emulsifier modifies gluten molecules and enhances its

Answer 29

film-forming power resulting in good spreadability and improvement of working efficiency. Thus, easy-rising bread can be obtained

Question 30

When fats and oils form into crystal, an emulsifier promotes and inhibits

Answer 30

the crystal growth which prevents the formation of abnormal crystal