carbohydrates

Question 1

What is raffinose ?

Answer 1

trisaccharide : galactose, glucose and fructose

Question 2

What is stachyose ?

Answer 2

glucose, fructose and two galactose

Question 3

When you want to make a caramel flavor, you use a ___ solution

Answer 3

sucrose

Question 4

When you want to make a caramel color, you use a ___ solution

Answer 4

glucose

Question 5

2 aminoketones will give a ___

Answer 5

pyrazine

Question 6

the more a sugar is ____ the more it will be sweet

Answer 6

soluble

Question 7

how can you mix prevent the crystallization

Answer 7

mix the sugars

Question 8

****what can you do if you want to minimize the browning you use ____ in your maillard reaction

Answer 8

sucrose

Question 9

T or F : the sugar alcohol are more sweet than sucrose or glucose

Answer 9

false, they are less sweet

Question 10

what is the only sugar alcohol with a sweetness comparable to sucrose

Answer 10

xylitol

Question 11

the ____ is hydrogenated to form xylitol

Answer 11

xylose

Question 12

___ is the polymer of xylose

Answer 12

xylan

Question 13

In amylopectine, every ____ glucoses molecules, there will be a a glucose that has two glycosidic bonds (one in the 1-4 and one in the 1-6)

Answer 13

12-20

Question 14

____ (starch) is more soluble in water

Answer 14

amylopectin

Question 15

Loss of granular integrity generally occurs between _____ gelatinization temperature is a function of the starch source.

Answer 15

60˚C and 70˚C

Question 16

why is the invert sugar called inverted sugar

Answer 16

because of the rotation of the solution from +66 to -39˚C.

Question 17

What is the general formula of carbohydrates

Answer 17

Cx(H2O)x

Question 18

What are the two optical isomers of glucose

Answer 18

glucose-D and L-glucose

Question 19

what is the only carbon at which isomers are not considered to be different sugars ?

Answer 19

the n-1 carbon

Question 20

fructose has a hemiketal or a hemiacetal

Answer 20

hemiketal

Question 21

glucose has a hemiketal or a hemiacetal?

Answer 21

hemiacetal

Question 22

T or F : in the pyranose form, the fructose has a hemiacetal

Answer 22

false

Question 23

Beta and alpha glucose are two ____

Answer 23

anomers

Question 24

the crystaline form of thre sugars is always ____

Answer 24

cyclical

Question 25

In solutions, there is a dynamic equilibrium between ___ ___and __

Answer 25

alpha, beta, open chain.

Question 26

the alpha-glucopyranose has an optical roation of _____

Answer 26

112˚

Question 27

the beta glucopyranose has an optical rotation of ____

Answer 27

19˚

Question 28

the active aldehyde form is the _____ form

Answer 28

open-chain

Question 29

T or F : all aldehydes are reducing sugars

Answer 29

true, because they have a free ketone or a free aldehyde

Question 30

What is the most common test of reducing sugars

Answer 30

the fehling’s test (cuII in copper tartate (blue) to cuI oxide (red))

Question 31

What are the two ways water can be eliminated from a sugar molecule

Answer 31

1. by forming a glycosidic bond with another sugar (random polymerization)
2. Elimination of water from within a sugar molecule leading to unsaturated molecule.

Question 32

how many water molecules are lost to make HMF

Answer 32

3

Question 33

what is the key intermidiate in the following reactions :
Caramelization
Maillard Reaction

Answer 33

Caramelization : HMF
Maillard reaction : amadori compound

Question 34

How are sugar alcohol produced?

Answer 34

produced by reducing the aldehyde group by an hydroxyl group (hydrogenation).

Question 35

what is the effect of the presence of sugars in the gel formation

Answer 35

retard the gel formation and retrogradation because they compete for available water and interfere with starch to starch.

Question 36

surfactants forms complex with starch, it is more noticeable for _____

Answer 36

amylose