Enzymes food application

Question 1

describe amylose structure

Answer 1

linear/straight chain
500-2000 units
alpha 1,4 glycosidic linkages

Question 2

describe amylopectin structure

Answer 2

branched chain
alpha 1, 4 linked glucose branches
alpha 1,6 branch point linkages

Question 3

describe starch hydrolysis in acidic conditions

Answer 3

random pattern

Question 4

describe starch hydrolysis through enzymatic conditoins

Answer 4

conntrolled attack

Question 5

what does thermostable alpha amylase turn starch into

Answer 5

dextrins
branched and linear oligos

Question 6

what does thermostable CGTase turn starch into

Answer 6

cyclodextrins

Question 7

how do dextrins turn into maltose + maltotriose

Answer 7

fungal alpha amylase

Question 8

two stages of turning starch into sugar

Answer 8

liquefaction
saccharfication

Question 9

enzymes that turn dextrins into glucose + high glucose syrup

Answer 9

amyloglucosidase
pulluanase

Question 10

enzymes that turn dextrins into maltose + high maltose syrup

Answer 10

pullaulanase
beta amylase

Question 11

how to turn glucose + high glucose sugar into crytalline sugar

Answer 11

crystalisation

Question 12

what does glucose isomerase turn glucose + high glucose syrup into?

Answer 12

fructose syrup

Question 13

describe liquefaction

Answer 13

enzyme cuts long chain of starch into dextrins or cyclodextrins depending on the enzyme added

Question 14

what must happen to the starch before liquefaction

Answer 14

must gelatinise in order for amylase to be able to attack it

Question 15

Pectinmethylesterase carrie out what type of reaction

Answer 15

hydrolysis

Question 16

what part of pectin does PMe attack

Answer 16

methyl group

Question 17

products PME and Pectin

Answer 17

methanol
polygalacturonic acid

Question 18

what happens to the polygalactoronic acid after hydrolysis

Answer 18

attacked by another enzyme
polygalacturonase

Question 19

product of polygalacturonase activity

Answer 19

shorter chain sugar

Question 20

other enzymes that breakdown shorter chain

Answer 20

pectin lyase

Question 21

what does PME do by removing the methyl group from pectin

Answer 21

creates a negative charge

Question 22

how does calcium bind to the hydrolysed pectin

Answer 22

the negative charge left by removing the methyl group allows calcium to bind

Question 23

what happens when pectin (only homogalacturonan) undergoes b-elimination at >80C and ph >4.5

Answer 23

texture/viscosity loss

Question 24

what happens when pectin (only homogalacturonan) undergoes hydrolysis by PME

Answer 24

same as in carrots, results in a product with negative charge.

Question 25

what can the product produced by PME react with in tomatoes

Answer 25

calcium: improved texture
PG and acid hydrolysis (ph<3): texture loss but improved juice extraction
PL: tecture and viscosity loss