Enzymes : food industry

Question 1

What are the advantages of using enzymes in food industry

Answer 1

1. perceived as natrual by consumer
2. specificity
3. activity under mild conditions
4. ease of control after desired process

Question 2

Where does the proteolytic enzymes cute the caseins of milk

Answer 2

kappa casein between the methionine 106 and the phenylalanine 105

Question 3

name the role of amylase in the baking industry

Answer 3

can break down the CHO into sugars that yeast can use

Question 4

name the role of lipase (lipoxygenase) in the baking industry

Answer 4

can break down the carotenoids pigments and bleach the flour

Question 5

name the role of protease in the baking industry

Answer 5

can break down gluten to make the dough more plaible

Question 6

what is the use of proteases in the meat industry

Answer 6

tenderization

Question 7

what is the role of transferase in the food industry

Answer 7

texturization because they can form bigger proteins.

Question 8

what is the difference between an exoprotease and an endoprotease

Answer 8

endoprotease : act randomly on the protein. They are used to if you want extensives changes.
exoprotease : act at the end of proteins. They don’t bring extensive changes in the peptide molecules

Question 9

___ are used to debitter proteins

Answer 9

exoproteases

Question 10

What are the two types of exoproteases?

Answer 10

aminoprotease

carboxyprotease

Question 11

What are the two major carbohydrates found in foods?

Answer 11

starch and cellulose

Question 12

___ is a CHO that is more resistant to enzymatic hydrolysis

Answer 12

cellulose

Question 13

What type of linkage is found in cellulose

Answer 13

beta-1-4 glycodisic bonds

Question 14

What type of linkage is found in cellulose

Answer 14

alpha 1-4 glycosidic bonds

Question 15

T or F : lipolytic enzymes cause degradation or modification of fats & oils

Answer 15

true, lipoytic enzymes is a synonym of lipase.

Question 16

T or F : action of lipase is of interest in the food industry because they create flavor compounds

Answer 16

false, Usually in food processing, action of lipases is undesirable, as the FFAs formed are less stable than the acyl glycerides, and are responsible for undesirable rancid odors. However, some product require lipolysis like cheese, milk, chocolat etc..

Question 17

What are the results of using enzymes on food

Answer 17

1. changes in solubility
2. changes in functinoal properties
3. changes in flavor

Question 18

name the industrial application of proteases

Answer 18

1. removal of bitterness
2. whey proteins hydrolysate
3. hydrolysis of gluten to use a flavorant
4. modfication of collagen and gelatin (collagenase)
5. alcoholic bev (chillproofing)
6. baking (removal of gluten for plability)
7. recovery of proteins from offal, bones and blood.

Question 19

state other lesser known application of enzymes

Answer 19

1. Removal of dental plaque with toothpaste containing dextranases;
2. Elimination of hair with keratinase;
3. Solubilization of cold tea solids with tannases;
4. Synthesis of protein-like molecules.

Question 20

why is cold tea less bitter than hot teas

Answer 20

because of the use of tannase to solubilise the tanins (bitter)

Question 21

What is the plastein reaction?

Answer 21

amino acids and low molecular peptides are put together by proteases to form gel-like protein curds products. How is it possible ? The hydrolysis by the proteases requires water (proteins to amino acids ) so without water, the inverse reaction can happen (amino acids to proteins )

Question 22

What are the methods use to control enzymatic reactions in foods

Answer 22

1. temperature
2. Aw
3. chemicals
4. high pressure treatment
5. enzyme treatment
6. enzymes inhibitors
7. chemical modifications
8. ionizing radiation

Question 23

how does the water activity reduction works to control enzymes

Answer 23

addition of substances like salt and sugar act to strip the moisture film surrounding enzymes and cause inactivation or to loose their activity.

Question 24

how does the chemicals works to control enzymes

Answer 24

Addition of chemicals acids / alkalis cause pH extremes where there is irreversible enzymes inactivation

Question 25

how does the high pressure works to control enzymes

Answer 25

cause compaction (reduced volume) of enzymes that results in changes in 3D configuration of enzyme and inactivation

Question 26

how does the chemical modification works to control enzymes

Answer 26

usually attaching alcohol to the proteins.

Question 27

how does the ionizing radiations works to control enzymes

Answer 27

can cause antioxydants and then causes the denatureation of enzymes.