week11C1: enzymes

Question 1

what is the enzyme that can hydrolyse all the way to glucose

Answer 1

the glucoamylase

Question 2

what is the name of the enzyme that hydrolyse the alpha-1-6 bonds

Answer 2

pullulunase

Question 3

what is the end product of the alpha-amylase

Answer 3

maltose, maltotriose and dextrins.

Question 4

what is the end product of the beta-amylase

Answer 4

maltose

Question 5

what is the target of pectinase

Answer 5

hydrolyse the methyl ester linkage of pectin.

Question 6

what is the pH range of papain

Answer 6

3-11 and it is stable at multiple temperatures

Question 7

what is the pH range of trypsin and chymotrypsin

Answer 7

7-9

Question 8

what is the enzyme used in chillproofing

Answer 8

papain. Pepsin can also be used.

Question 9

what is the pH range of pepsin

Answer 9

1.8

Question 10

what is the target of the chymosin

Answer 10

hydrolyse the bond between the phe-105 and the meth-106 of the k-casein

Question 11

give an example of bacterial protease and the use of it

Answer 11

subtilisin from bacillus subtilisin can be used for beer chillproofing.

Question 12

what is the target of the lipases

Answer 12

the ester bonds between FA and the glycerol

Question 13

where does lipase work?

Answer 13

at the water-oil interface

Question 14

what are the two classes of lipases

Answer 14

1-3-lipases

2-lipases

Question 15

what is the target of lipoxygenase

Answer 15

cis,cis-1.4-pentadiaene unit

Question 16

what are the two uses of the lipoxygenase in food

Answer 16

1-can bleach wheat

2- can contribute to the formation of s-s bonds in gluten in dough.

Question 17

what is the target of polyphenol oxidase

Answer 17

oxidation of phenolic compounds.

Question 18

what are the inhibitors of PPO

Answer 18

removing o2
pH under 4.5 
Ascorbic acid (vitamin-C). 
Bi-sulfites 
EDTA