Carbohydrates

Question 1

Define a carbohydrate.

Answer 1

Polyhydroxy aldehydes, polyhydroxy ketons, and compounds derived from simple carbohydrates through reduction, oxidation, substitution, and condensation

Question 2

T or F. All carbohydrates are sweet.

Answer 2

False

Question 3

T or F. Monosaccharides are the simplest carbohydrates.

Answer 3

True.

Question 4

T or F. All aldohexoses are reducing sugars.

Answer 4

True

Question 5

A uronic acid id produced when hydroxyl group in a hexose is oxidized at what carbon?

Answer 5

C6

Question 6

The Fehling’s test is used to determine what?

Answer 6

reducing sugars

Question 7

Polyols are produced from sugars by what process?

Answer 7

reduction

Question 8

Required substrate(s) for caramelization reactions is?

Answer 8

only carbohydrates

Question 9

Carbohydrates that may serve as substrate in Maillard reactions are:

Answer 9

reducing sugars

Question 10

The molecule for sucrose is:

Answer 10

aGlucose (1-2)BFructose

Question 11

The molecule for lactose is:

Answer 11

BGalactose(1-4)Glucose

Question 12

Which of these is a tetrasaccharide?

a. sucrose
b. maltotriose
c. manitol
d. raffinose
e. stachyose

Answer 12

e. stachyose

Question 13

If all solutions were prepared with the same concentration of sugars and amino acids and were heated 2 hrs at 100 degree C, which one will have the most Maillard reaction product:

a. glucose, lysine, pH 9, in water
b. maltose, tyrosine, pH 7, in water with sulfites
c. lactose, proline, pH 4, in water
d. fructose, glycine, pH 9, in water
e. sucrose, cysteine, pH 11, in water

Answer 13

a. glucose, lysine, pH 9, in water

Question 14

What is a reducing power of maltotetrose compared to reducing power of glucose?

Answer 14

25%

Question 15

T or F. Addition of ammonia compounds is allowed in production of certain types of caramels.

Answer 15

True

Question 16

T or F. When sugar caramelizes, its caloric value decreases.

Answer 16

True

Question 17

Caramelization reactions include:

Answer 17

melting, dehydration, fragmentation, and condensation

Question 18

T or F. Glycosidic bond is more susceptible to acid hydrolysis than peptide bonds.

Answer 18

True

Question 19

Which sweetener will provide cooling effect while being dissolved?

Answer 19

some polyols - xylitol

Question 20

T or F. If two polysaccharides, one linear and one highly branched, have the same molecular weight and make solutions of the same concentration, solutions of the linear polysaccharide will be more viscous.

Answer 20

True

Question 21

Oxidation of monosaccharaides results in formation of:

Answer 21

polyhydroxy alcohols

Question 22

High amylose starch contains:

Answer 22

50-70% amylose

Question 23

Diameter of starch granules is:

Answer 23

2-100 micrometer

Question 24

In waxy starches, amylose content is:

Answer 24

< 2%

Question 25

What is the reducing power of maltopentose compared to reducing power of glucose?

Answer 25

1/5 (20%)

Question 26

The largest starch granule is what?

Answer 26

potato

Question 27

Consider two corn syrups with DE of 25 and 85. The corn syrup that has thicker texture (more viscous) and less sweetness is which one?

Answer 27

DE ~ 25

Question 28

Define gelatinization.

Answer 28

The irreversible swelling of starch granules under the influence of heat in an aqueous medium to give a starch paste

Question 29

The last enzyme used in production of HFCS is:

Answer 29

isomerase

Question 30

B-amylase hydrolyzes amylopectin at:

Answer 30

a 1-4 bonds, two glucose from non-reducing end

Question 31

Maltodextrins have a DE of:

Answer 31

5-25