Unit 4-5

Question 1

How can we plan to synthesize a flavor compound:

Answer 1

• retrosynthesis
• reverse engineering
• disconnection approach

Question 2

Target molecule:

Answer 2

The molecule to be synthesized

Question 3

An imaginary bond breaking corresponding to the reverse of a real reaction:

Answer 3

disconnection

Question 4

Functional group interconversion (FGI):

Answer 4

The process of interconverting one functional into another during retrosynthetic analysis

Question 5

The process of breaking down a target molecule into available starting materials by disconnection or FGI:

Answer 5

Synthesis backwards

Question 6

A double line arrow used to indicate the reverse of a synthetic reaction:

Answer 6

retrosynthetic arrow

Question 7

What is a synthon:

Answer 7

an idelised fragment (usually a cation or anion) resulting from a disconnection

Question 8

A real chemical compound (reagent) carrying out the function of a synthon:

Answer 8

synthetic equivalent

Question 9

__________________ is breaking (disconnecting) a target molecule (a molecule we want to synthesize in the lab) on the paper into 2 simpler fragments in such way that they can be reconnected by a known chemical transformation

Answer 9

retrosynthesis

Question 10

T or F: Heat causes the formation of heterocyclic compounds

Answer 10

T

Question 11

The overall flavor of foods results not only from carbohydrates, lipids, alcohols, phenols and carbonyl compounds, but also from the various _______________

Answer 11

heterocyclic compounds

Question 12

T or F: Heterocyclic compounds are present in flavors in such minute traces that before the advent of gas-liquid chromatography (GC), specially in combination with mass spectrometry (GC-MS), they were impossible to detect

Answer 12

T

Question 13

Although heterocyclic compounds are present only in minute amounts in foods, they constitute the most important character impact compounds (top notes) because of their ___________________

Answer 13

low threshold values

Question 14

T or F: almost half of the six thousand flavor compounds identified till now, are heterocyclic in nature

Answer 14

T

Question 15

Many N- and S- containing heterocyclic compounds have been identified in the aroma fraction of foods. In roasted products such as coffee and heat-treated foods (baked bread or fried meat). These heterocyclic compounds are formed from reducing sugars and amino acids by the _______________

Answer 15

Maillard reaction

Question 16

T or F: numerous furan and pyran derivatives, many of which originate from heat treatment of carbohydrates, largely determine the odor of _________________

Answer 16

processed food

Question 17

T or F; 2,5-dimethyl-4-hydroxy-2H-furan -3-one and maltol are used in fairly large quantities

Answer 17

T

Question 18

Furans are mainly associated with ______________________ notes

Answer 18

• caramel-like
• sweet
• fruity
• nutty
• meaty
• burnt

Question 19

Furans are formed in food by:

*they are almost present in all food aromas and essential oils

Answer 19

thermal degradation of cabohydrates and by the Maillard reaction

Question 20

Maltol is used in aroma compositions with a ______________ and as a taste intensifier in fruit flavors, particularly in strawberry flavor compositions

Answer 20

caramel note

Question 21

Thiophenes can significantly contribute to the sensory properties of foods, but they are not as numerous as __________

Answer 21

furans

Question 22

of the 26 sulfur containing compounds identified in pressure-cooked lean ground beef ___ were thiophenes

Answer 22

20